From 8adcf5083ffc12532ecca7594a2192acd954dd3a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Thu, 15 Oct 2020 23:32:07 +0900
Subject: [PATCH 01/23] wip

---
 Cargo.lock           | 302 +++++++++++++++++++++++++++++++++++++++++++
 Cargo.toml           |   1 +
 helix-lsp/Cargo.toml |  15 +++
 helix-lsp/src/lib.rs |  71 ++++++++++
 4 files changed, 389 insertions(+)
 create mode 100644 helix-lsp/Cargo.toml
 create mode 100644 helix-lsp/src/lib.rs

diff --git a/Cargo.lock b/Cargo.lock
index 0a3137d9..9333a518 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -21,6 +21,18 @@ version = "0.4.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4d25d88fd6b8041580a654f9d0c581a047baee2b3efee13275f2fc392fc75034"
 
+[[package]]
+name = "arrayref"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4c527152e37cf757a3f78aae5a06fbeefdb07ccc535c980a3208ee3060dd544"
+
+[[package]]
+name = "arrayvec"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cff77d8686867eceff3105329d4698d96c2391c176d5d03adc90c7389162b5b8"
+
 [[package]]
 name = "async-channel"
 version = "1.5.1"
@@ -132,12 +144,29 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cdb031dd78e28731d87d56cc8ffef4a8f36ca26c38fe2de700543e627f8a464a"
 
+[[package]]
+name = "base64"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3441f0f7b02788e948e47f457ca01f1d7e6d92c693bc132c22b087d3141c03ff"
+
 [[package]]
 name = "bitflags"
 version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 
+[[package]]
+name = "blake2b_simd"
+version = "0.5.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8fb2d74254a3a0b5cac33ac9f8ed0e44aa50378d9dbb2e5d83bd21ed1dc2c8a"
+dependencies = [
+ "arrayref",
+ "arrayvec",
+ "constant_time_eq",
+]
+
 [[package]]
 name = "blocking"
 version = "1.0.2"
@@ -212,6 +241,23 @@ dependencies = [
  "cache-padded",
 ]
 
+[[package]]
+name = "constant_time_eq"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "245097e9a4535ee1e3e3931fcfcd55a796a44c643e8596ff6566d68f09b87bbc"
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3c7c73a2d1e9fc0886a08b93e98eb643461230d5f1925e4036204d5f2e261a8"
+dependencies = [
+ "autocfg",
+ "cfg-if",
+ "lazy_static",
+]
+
 [[package]]
 name = "crossterm"
 version = "0.18.0"
@@ -238,6 +284,27 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "dirs"
+version = "2.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13aea89a5c93364a98e9b37b2fa237effbb694d5cfe01c5b70941f7eb087d5e3"
+dependencies = [
+ "cfg-if",
+ "dirs-sys",
+]
+
+[[package]]
+name = "dirs-sys"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e93d7f5705de3e49895a2b5e0b8855a1c27f080192ae9c32a6432d50741a57a"
+dependencies = [
+ "libc",
+ "redox_users",
+ "winapi",
+]
+
 [[package]]
 name = "event-listener"
 version = "2.5.1"
@@ -290,6 +357,23 @@ dependencies = [
  "waker-fn",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.1.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc587bc0ec293155d5bfa6b9891ec18a1e330c234f896ea47fbada4cadbe47e6"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "glob"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
+
 [[package]]
 name = "hashbrown"
 version = "0.9.1"
@@ -312,6 +396,18 @@ dependencies = [
  "unicode-width",
 ]
 
+[[package]]
+name = "helix-lsp"
+version = "0.1.0"
+dependencies = [
+ "glob",
+ "lsp-types",
+ "pathdiff",
+ "shellexpand",
+ "smol",
+ "url",
+]
+
 [[package]]
 name = "helix-syntax"
 version = "0.1.0"
@@ -354,6 +450,17 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "idna"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "02e2673c30ee86b5b96a9cb52ad15718aa1f966f5ab9ad54a8b95d5ca33120a9"
+dependencies = [
+ "matches",
+ "unicode-bidi",
+ "unicode-normalization",
+]
+
 [[package]]
 name = "indexmap"
 version = "1.6.0"
@@ -373,6 +480,12 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "itoa"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc6f3ad7b9d11a0c00842ff8de1b60ee58661048eb8049ed33c73594f359d7e6"
+
 [[package]]
 name = "jobserver"
 version = "0.1.21"
@@ -412,12 +525,32 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "lsp-types"
+version = "0.82.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "db895abb8527cf59e3de893ab2acf52cf904faeb65e60ea6f373e11fe86464e8"
+dependencies = [
+ "base64",
+ "bitflags",
+ "serde",
+ "serde_json",
+ "serde_repr",
+ "url",
+]
+
 [[package]]
 name = "mac"
 version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c41e0c4fef86961ac6d6f8a82609f55f31b05e4fce149ac5710e439df7619ba4"
 
+[[package]]
+name = "matches"
+version = "0.1.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7ffc5c5338469d4d3ea17d269fa8ea3512ad247247c30bd2df69e68309ed0a08"
+
 [[package]]
 name = "memchr"
 version = "2.3.3"
@@ -526,6 +659,18 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "pathdiff"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "877630b3de15c0b64cc52f659345724fbf6bdad9bd9566699fc53688f3c34a34"
+
+[[package]]
+name = "percent-encoding"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d4fd5641d01c8f18a23da7b6fe29298ff4b55afcccdf78973b24cf3175fee32e"
+
 [[package]]
 name = "pin-project-lite"
 version = "0.1.10"
@@ -545,12 +690,41 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "proc-macro2"
+version = "1.0.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e0704ee1a7e00d7bb417d0770ea303c1bccbabf0ef1667dae92b5967f5f8a71"
+dependencies = [
+ "unicode-xid",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa563d17ecb180e500da1cfd2b028310ac758de548efdd203e18f283af693f37"
+dependencies = [
+ "proc-macro2",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.1.57"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "41cc0f7e4d5d4544e8861606a285bb08d3e70712ccc7d2b84d7c0ccfaf4b05ce"
 
+[[package]]
+name = "redox_users"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "de0737333e7a9502c789a36d7c7fa6092a49895d4faa31ca5df163857ded2e9d"
+dependencies = [
+ "getrandom",
+ "redox_syscall",
+ "rust-argon2",
+]
+
 [[package]]
 name = "regex"
 version = "1.4.1"
@@ -578,12 +752,81 @@ dependencies = [
  "smallvec",
 ]
 
+[[package]]
+name = "rust-argon2"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9dab61250775933275e84053ac235621dfb739556d5c54a2f2e9313b7cf43a19"
+dependencies = [
+ "base64",
+ "blake2b_simd",
+ "constant_time_eq",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "ryu"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e"
+
 [[package]]
 name = "scopeguard"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
+[[package]]
+name = "serde"
+version = "1.0.116"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "96fe57af81d28386a513cbc6858332abc6117cfdb5999647c6444b8f43a370a5"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.116"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f630a6370fd8e457873b4bd2ffdae75408bc291ba72be773772a4c2a065d9ae8"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "serde_json"
+version = "1.0.59"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dcac07dbffa1c65e7f816ab9eba78eb142c6d44410f4eeba1e26e4f5dfa56b95"
+dependencies = [
+ "itoa",
+ "ryu",
+ "serde",
+]
+
+[[package]]
+name = "serde_repr"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2dc6b7951b17b051f3210b063f12cc17320e2fe30ae05b0fe2a3abb068551c76"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "shellexpand"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a2b22262a9aaf9464d356f656fea420634f78c881c5eebd5ef5e66d8b9bc603"
+dependencies = [
+ "dirs",
+]
+
 [[package]]
 name = "signal-hook"
 version = "0.1.16"
@@ -641,6 +884,17 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "syn"
+version = "1.0.44"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e03e57e4fcbfe7749842d53e24ccb9aa12b7252dbe5e91d2acad31834c8b8fdd"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-xid",
+]
+
 [[package]]
 name = "tendril"
 version = "0.4.1"
@@ -669,6 +923,12 @@ dependencies = [
  "lazy_static",
 ]
 
+[[package]]
+name = "tinyvec"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "238ce071d267c5710f9d31451efec16c5ee22de34df17cc05e56cbc92e967117"
+
 [[package]]
 name = "tree-sitter"
 version = "0.17.0"
@@ -691,6 +951,24 @@ dependencies = [
  "unicode-width",
 ]
 
+[[package]]
+name = "unicode-bidi"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "49f2bd0c6468a8230e1db229cff8029217cf623c767ea5d60bfbd42729ea54d5"
+dependencies = [
+ "matches",
+]
+
+[[package]]
+name = "unicode-normalization"
+version = "0.1.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6fb19cf769fa8c6a80a162df694621ebeb4dafb606470b2b2fce0be40a98a977"
+dependencies = [
+ "tinyvec",
+]
+
 [[package]]
 name = "unicode-segmentation"
 version = "1.6.0"
@@ -703,6 +981,24 @@ version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9337591893a19b88d8d87f2cec1e73fad5cdfd10e5a6f349f498ad6ea2ffb1e3"
 
+[[package]]
+name = "unicode-xid"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7fe0bb3479651439c9112f72b6c505038574c9fbb575ed1bf3b797fa39dd564"
+
+[[package]]
+name = "url"
+version = "2.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "829d4a8476c35c9bf0bbce5a3b23f4106f79728039b726d292bb93bc106787cb"
+dependencies = [
+ "idna",
+ "matches",
+ "percent-encoding",
+ "serde",
+]
+
 [[package]]
 name = "utf-8"
 version = "0.7.5"
@@ -727,6 +1023,12 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9d5b2c62b4012a3e1eca5a7e077d13b3bf498c4073e33ccd58626607748ceeca"
 
+[[package]]
+name = "wasi"
+version = "0.9.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
+
 [[package]]
 name = "wepoll-sys"
 version = "3.0.0"
diff --git a/Cargo.toml b/Cargo.toml
index 25dbe725..d7dab22e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,6 +4,7 @@ members = [
   "helix-view",
   "helix-term",
   "helix-syntax",
+  "helix-lsp",
 ]
 
 # Build helix-syntax in release mode to make the code path faster in development.
diff --git a/helix-lsp/Cargo.toml b/helix-lsp/Cargo.toml
new file mode 100644
index 00000000..6fd59bf4
--- /dev/null
+++ b/helix-lsp/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "helix-lsp"
+version = "0.1.0"
+authors = ["Blaž Hrastnik <blaz@mxxn.io>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+lsp-types = { version = "0.82", features = ["proposed"] }
+smol = "1.2"
+url = "2.1.1"
+pathdiff = "0.2.0"
+shellexpand = "2.0.0"
+glob = "0.3.0"
diff --git a/helix-lsp/src/lib.rs b/helix-lsp/src/lib.rs
new file mode 100644
index 00000000..14d53bea
--- /dev/null
+++ b/helix-lsp/src/lib.rs
@@ -0,0 +1,71 @@
+use std::{
+    collections::HashMap,
+    process::{ChildStderr, ChildStdin, ChildStdout, Command, Stdio},
+};
+
+use smol::io::{BufReader, BufWriter};
+use smol::prelude::*;
+use smol::Unblock;
+
+struct Client {
+    // process: Command,
+    reader: BufReader<Unblock<ChildStdout>>,
+}
+
+impl Client {
+    fn start(cmd: &str, args: &[String]) -> Self {
+        let mut process = Command::new(cmd)
+            .args(args)
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped())
+            .spawn()
+            .expect("Failed to start language server");
+        // TODO: impl drop that kills the process
+
+        // TODO: do we need bufreader/writer here? or do we use async wrappers on unblock?
+        let writer = BufWriter::new(Unblock::new(
+            process.stdin.take().expect("Failed to open stdin"),
+        ));
+        let reader = BufReader::new(Unblock::new(
+            process.stdout.take().expect("Failed to open stdout"),
+        ));
+        let stderr = BufReader::new(Unblock::new(
+            process.stderr.take().expect("Failed to open stderr"),
+        ));
+
+        Client { reader }
+    }
+
+    async fn receiver(&mut self) -> Result<(), std::io::Error> {
+        let mut headers: HashMap<String, String> = HashMap::default();
+        loop {
+            // read headers
+            loop {
+                let mut header = String::new();
+                // detect pipe closed if 0
+                self.reader.read_line(&mut header).await?;
+                let header = header.trim();
+
+                if header.is_empty() {
+                    break;
+                }
+
+                let parts: Vec<&str> = header.split(": ").collect();
+                if parts.len() != 2 {
+                    // return Err(Error::new(ErrorKind::Other, "Failed to parse header"));
+                    panic!()
+                }
+                headers.insert(parts[0].to_string(), parts[1].to_string());
+            }
+
+            // find content-length
+
+            // read data
+            // decode via serde_json decoding into jsonrpc_core Output
+            break;
+        }
+
+        Ok(())
+    }
+}

From f03830b047f0db9d9bb4576f771b5988329be46f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Sun, 18 Oct 2020 18:01:06 +0900
Subject: [PATCH 02/23] wip: Basic LSP lifecycle requests/notifications.

---
 Cargo.lock             | 106 +++++++++++
 helix-lsp/Cargo.toml   |   9 +-
 helix-lsp/src/lib.rs   | 394 ++++++++++++++++++++++++++++++++++++-----
 helix-term/Cargo.toml  |   1 +
 helix-term/src/main.rs |  11 +-
 5 files changed, 472 insertions(+), 49 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 9333a518..999a55b1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -330,6 +330,12 @@ dependencies = [
  "new_debug_unreachable",
 ]
 
+[[package]]
+name = "futures"
+version = "0.1.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c7e4c2612746b0df8fed4ce0c69156021b704c9aefa360311c04e6e9e002eed"
+
 [[package]]
 name = "futures-core"
 version = "0.3.6"
@@ -357,6 +363,43 @@ dependencies = [
  "waker-fn",
 ]
 
+[[package]]
+name = "futures-macro"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f57ed14da4603b2554682e9f2ff3c65d7567b53188db96cb71538217fc64581b"
+dependencies = [
+ "proc-macro-hack",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "futures-task"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4dd26820a9f3637f1302da8bceba3ff33adbe53464b54ca24d4e2d4f1db30f94"
+dependencies = [
+ "once_cell",
+]
+
+[[package]]
+name = "futures-util"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a894a0acddba51a2d49a6f4263b1e64b8c579ece8af50fa86503d52cd1eea34"
+dependencies = [
+ "futures-core",
+ "futures-macro",
+ "futures-task",
+ "pin-project",
+ "pin-utils",
+ "proc-macro-hack",
+ "proc-macro-nested",
+ "slab",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.1.15"
@@ -400,9 +443,14 @@ dependencies = [
 name = "helix-lsp"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
+ "futures-util",
  "glob",
+ "jsonrpc-core",
  "lsp-types",
  "pathdiff",
+ "serde",
+ "serde_json",
  "shellexpand",
  "smol",
  "url",
@@ -424,6 +472,7 @@ dependencies = [
  "clap",
  "crossterm",
  "helix-core",
+ "helix-lsp",
  "helix-view",
  "num_cpus",
  "smol",
@@ -495,6 +544,19 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "jsonrpc-core"
+version = "15.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0745a6379e3edc893c84ec203589790774e4247420033e71a76d3ab4687991fa"
+dependencies = [
+ "futures",
+ "log",
+ "serde",
+ "serde_derive",
+ "serde_json",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
@@ -671,12 +733,38 @@ version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d4fd5641d01c8f18a23da7b6fe29298ff4b55afcccdf78973b24cf3175fee32e"
 
+[[package]]
+name = "pin-project"
+version = "0.4.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2ffbc8e94b38ea3d2d8ba92aea2983b503cd75d0888d75b86bb37970b5698e15"
+dependencies = [
+ "pin-project-internal",
+]
+
+[[package]]
+name = "pin-project-internal"
+version = "0.4.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "65ad2ae56b6abe3a1ee25f15ee605bacadb9a764edaba9c2bf4103800d4a1895"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "pin-project-lite"
 version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e555d9e657502182ac97b539fb3dae8b79cda19e3e4f8ffb5e8de4f18df93c95"
 
+[[package]]
+name = "pin-utils"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
+
 [[package]]
 name = "polling"
 version = "2.0.1"
@@ -690,6 +778,18 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "proc-macro-hack"
+version = "0.5.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "99c605b9a0adc77b7211c6b1f722dcb613d68d66859a44f3d485a6da332b0598"
+
+[[package]]
+name = "proc-macro-nested"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eba180dafb9038b050a4c280019bbedf9f2467b61e5d892dcad585bb57aadc5a"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.24"
@@ -848,6 +948,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "slab"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
+
 [[package]]
 name = "smallvec"
 version = "1.4.2"
diff --git a/helix-lsp/Cargo.toml b/helix-lsp/Cargo.toml
index 6fd59bf4..1942fc24 100644
--- a/helix-lsp/Cargo.toml
+++ b/helix-lsp/Cargo.toml
@@ -9,7 +9,12 @@ edition = "2018"
 [dependencies]
 lsp-types = { version = "0.82", features = ["proposed"] }
 smol = "1.2"
-url = "2.1.1"
+url = "2"
 pathdiff = "0.2.0"
 shellexpand = "2.0.0"
-glob = "0.3.0"
+glob = "0.3"
+anyhow = "1"
+serde_json = "1.0"
+serde = { version = "1.0", features = ["derive"] }
+jsonrpc-core = "15.1"
+futures-util = "0.3"
diff --git a/helix-lsp/src/lib.rs b/helix-lsp/src/lib.rs
index 14d53bea..b371f337 100644
--- a/helix-lsp/src/lib.rs
+++ b/helix-lsp/src/lib.rs
@@ -1,19 +1,44 @@
-use std::{
-    collections::HashMap,
-    process::{ChildStderr, ChildStdin, ChildStdout, Command, Stdio},
-};
+use std::collections::HashMap;
 
+use jsonrpc_core as jsonrpc;
+use lsp_types as lsp;
+
+use serde::{Deserialize, Serialize};
+use serde_json::Value;
+
+use smol::channel::{Receiver, Sender};
 use smol::io::{BufReader, BufWriter};
 use smol::prelude::*;
-use smol::Unblock;
+use smol::process::{Child, ChildStderr, ChildStdin, ChildStdout, Command, Stdio};
+use smol::Executor;
 
-struct Client {
-    // process: Command,
-    reader: BufReader<Unblock<ChildStdout>>,
+use futures_util::{select, FutureExt};
+
+/// A type representing all possible values sent from the server to the client.
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(deny_unknown_fields)]
+#[serde(untagged)]
+enum Message {
+    /// A regular JSON-RPC request output (single response).
+    Output(jsonrpc::Output),
+    /// A notification.
+    Notification(jsonrpc::Notification),
+    /// A JSON-RPC request
+    Call(jsonrpc::Call),
+}
+
+pub struct Client {
+    process: Child,
+    stderr: BufReader<ChildStderr>,
+    outgoing: Sender<Payload>,
+
+    pub request_counter: u64,
+
+    capabilities: Option<lsp::ServerCapabilities>,
 }
 
 impl Client {
-    fn start(cmd: &str, args: &[String]) -> Self {
+    pub fn start(ex: &Executor, cmd: &str, args: &[String]) -> Self {
         let mut process = Command::new(cmd)
             .args(args)
             .stdin(Stdio::piped())
@@ -21,51 +46,332 @@ impl Client {
             .stderr(Stdio::piped())
             .spawn()
             .expect("Failed to start language server");
-        // TODO: impl drop that kills the process
+        // smol makes sure the process is reaped on drop, but using kill_on_drop(true) maybe?
 
         // TODO: do we need bufreader/writer here? or do we use async wrappers on unblock?
-        let writer = BufWriter::new(Unblock::new(
-            process.stdin.take().expect("Failed to open stdin"),
-        ));
-        let reader = BufReader::new(Unblock::new(
-            process.stdout.take().expect("Failed to open stdout"),
-        ));
-        let stderr = BufReader::new(Unblock::new(
-            process.stderr.take().expect("Failed to open stderr"),
-        ));
+        let writer = BufWriter::new(process.stdin.take().expect("Failed to open stdin"));
+        let reader = BufReader::new(process.stdout.take().expect("Failed to open stdout"));
+        let stderr = BufReader::new(process.stderr.take().expect("Failed to open stderr"));
 
-        Client { reader }
+        let (incoming, outgoing) = Transport::start(ex, reader, writer);
+
+        Client {
+            process,
+            stderr,
+            outgoing,
+
+            request_counter: 0,
+
+            capabilities: None,
+        }
     }
 
-    async fn receiver(&mut self) -> Result<(), std::io::Error> {
-        let mut headers: HashMap<String, String> = HashMap::default();
-        loop {
-            // read headers
-            loop {
-                let mut header = String::new();
-                // detect pipe closed if 0
-                self.reader.read_line(&mut header).await?;
-                let header = header.trim();
+    fn next_request_id(&mut self) -> jsonrpc::Id {
+        let id = jsonrpc::Id::Num(self.request_counter);
+        self.request_counter += 1;
+        id
+    }
 
-                if header.is_empty() {
-                    break;
-                }
+    fn to_params(value: Value) -> anyhow::Result<jsonrpc::Params> {
+        use jsonrpc::Params;
 
-                let parts: Vec<&str> = header.split(": ").collect();
-                if parts.len() != 2 {
-                    // return Err(Error::new(ErrorKind::Other, "Failed to parse header"));
-                    panic!()
-                }
-                headers.insert(parts[0].to_string(), parts[1].to_string());
-            }
+        let params = match value {
+            Value::Null => Params::None,
+            Value::Bool(_) | Value::Number(_) | Value::String(_) => Params::Array(vec![value]),
+            Value::Array(vec) => Params::Array(vec),
+            Value::Object(map) => Params::Map(map),
+        };
 
-            // find content-length
+        Ok(params)
+    }
 
-            // read data
-            // decode via serde_json decoding into jsonrpc_core Output
-            break;
-        }
+    pub async fn request<R: lsp::request::Request>(
+        &mut self,
+        params: R::Params,
+    ) -> anyhow::Result<R::Result>
+    where
+        R::Params: serde::Serialize,
+        R::Result: core::fmt::Debug, // TODO: temporary
+    {
+        let params = serde_json::to_value(params)?;
+
+        let request = jsonrpc::MethodCall {
+            jsonrpc: Some(jsonrpc::Version::V2),
+            id: self.next_request_id(),
+            method: R::METHOD.to_string(),
+            params: Self::to_params(params)?,
+        };
+
+        let (tx, rx) = smol::channel::bounded::<anyhow::Result<Value>>(1);
+
+        self.outgoing
+            .send(Payload::Request {
+                chan: tx,
+                value: request,
+            })
+            .await?;
+
+        let response = rx.recv().await??;
+
+        let response = serde_json::from_value(response)?;
+
+        // TODO: we should pass request to a sender thread via a channel
+        // so it can't be interleaved
+
+        // TODO: responses can be out of order, we need to register a single shot response channel
+
+        Ok(response)
+    }
+
+    pub async fn notify<R: lsp::notification::Notification>(
+        &mut self,
+        params: R::Params,
+    ) -> anyhow::Result<()>
+    where
+        R::Params: serde::Serialize,
+    {
+        let params = serde_json::to_value(params)?;
+
+        let notification = jsonrpc::Notification {
+            jsonrpc: Some(jsonrpc::Version::V2),
+            method: R::METHOD.to_string(),
+            params: Self::to_params(params)?,
+        };
+
+        self.outgoing
+            .send(Payload::Notification(notification))
+            .await?;
 
         Ok(())
     }
+
+    // -------------------------------------------------------------------------------------------
+    // General messages
+    // -------------------------------------------------------------------------------------------
+
+    pub async fn initialize(&mut self) -> anyhow::Result<()> {
+        // TODO: delay any requests that are triggered prior to initialize
+
+        #[allow(deprecated)]
+        let params = lsp::InitializeParams {
+            process_id: Some(u64::from(std::process::id())),
+            root_path: None,
+            // root_uri: Some(lsp_types::Url::parse("file://localhost/")?),
+            root_uri: None, // set to project root in the future
+            initialization_options: None,
+            capabilities: lsp::ClientCapabilities::default(),
+            trace: None,
+            workspace_folders: None,
+            client_info: None,
+        };
+
+        let response = self.request::<lsp::request::Initialize>(params).await?;
+        self.capabilities = Some(response.capabilities);
+
+        // next up, notify<initialized>
+        self.notify::<lsp::notification::Initialized>(lsp::InitializedParams {})
+            .await?;
+
+        Ok(())
+    }
+
+    pub async fn shutdown(&mut self) -> anyhow::Result<()> {
+        self.request::<lsp::request::Shutdown>(()).await
+    }
+
+    pub async fn exit(&mut self) -> anyhow::Result<()> {
+        self.notify::<lsp::notification::Exit>(()).await
+    }
+
+    // -------------------------------------------------------------------------------------------
+    // Text document
+    // -------------------------------------------------------------------------------------------
+
+    pub async fn text_document_did_open(&mut self) -> anyhow::Result<()> {
+        self.notify::<lsp::notification::DidOpenTextDocument>(lsp::DidOpenTextDocumentParams {
+            text_document: lsp::TextDocumentItem {
+                uri: lsp::Url::parse(".")?,
+                language_id: "rust".to_string(),
+                version: 0,
+                text: "".to_string(),
+            },
+        })
+        .await
+    }
+
+    pub async fn text_document_did_change(&mut self) -> anyhow::Result<()> {
+        unimplemented!()
+    }
+
+    // will_save / will_save_wait_until
+
+    pub async fn text_document_did_save(&mut self) -> anyhow::Result<()> {
+        unimplemented!()
+    }
+
+    pub async fn text_document_did_close(&mut self) -> anyhow::Result<()> {
+        unimplemented!()
+    }
+}
+
+enum Payload {
+    Request {
+        chan: Sender<anyhow::Result<Value>>,
+        value: jsonrpc::MethodCall,
+    },
+    Notification(jsonrpc::Notification),
+}
+
+struct Transport {
+    incoming: Sender<Message>,
+    outgoing: Receiver<Payload>,
+
+    pending_requests: HashMap<jsonrpc::Id, Sender<anyhow::Result<Value>>>,
+    headers: HashMap<String, String>,
+
+    writer: BufWriter<ChildStdin>,
+    reader: BufReader<ChildStdout>,
+}
+
+impl Transport {
+    pub fn start(
+        ex: &Executor,
+        reader: BufReader<ChildStdout>,
+        writer: BufWriter<ChildStdin>,
+    ) -> (Receiver<Message>, Sender<Payload>) {
+        let (incoming, rx) = smol::channel::unbounded();
+        let (tx, outgoing) = smol::channel::unbounded();
+
+        let transport = Self {
+            reader,
+            writer,
+            incoming,
+            outgoing,
+            pending_requests: Default::default(),
+            headers: Default::default(),
+        };
+
+        ex.spawn(transport.duplex()).detach();
+
+        (rx, tx)
+    }
+
+    async fn recv(
+        reader: &mut (impl AsyncBufRead + Unpin),
+        headers: &mut HashMap<String, String>,
+    ) -> Result<Message, std::io::Error> {
+        // read headers
+        loop {
+            let mut header = String::new();
+            // detect pipe closed if 0
+            reader.read_line(&mut header).await?;
+            let header = header.trim();
+
+            if header.is_empty() {
+                break;
+            }
+
+            let parts: Vec<&str> = header.split(": ").collect();
+            if parts.len() != 2 {
+                // return Err(Error::new(ErrorKind::Other, "Failed to parse header"));
+                panic!()
+            }
+            headers.insert(parts[0].to_string(), parts[1].to_string());
+        }
+
+        // find content-length
+        let content_length = headers.get("Content-Length").unwrap().parse().unwrap();
+
+        let mut content = vec![0; content_length];
+        reader.read_exact(&mut content).await?;
+        let msg = String::from_utf8(content).unwrap();
+
+        // read data
+
+        // try parsing as output (server response) or call (server request)
+        let output: serde_json::Result<Message> = serde_json::from_str(&msg);
+
+        Ok(output?)
+    }
+
+    pub async fn send_payload(&mut self, payload: Payload) -> anyhow::Result<()> {
+        match payload {
+            Payload::Request { chan, value } => {
+                self.pending_requests.insert(value.id.clone(), chan);
+
+                let json = serde_json::to_string(&value)?;
+                self.send(json).await
+            }
+            Payload::Notification(value) => {
+                let json = serde_json::to_string(&value)?;
+                self.send(json).await
+            }
+        }
+    }
+
+    pub async fn send(&mut self, request: String) -> anyhow::Result<()> {
+        println!("-> {}", request);
+
+        // send the headers
+        self.writer
+            .write_all(format!("Content-Length: {}\r\n\r\n", request.len()).as_bytes())
+            .await?;
+
+        // send the body
+        self.writer.write_all(request.as_bytes()).await?;
+
+        self.writer.flush().await?;
+
+        Ok(())
+    }
+
+    pub async fn recv_response(&mut self, output: jsonrpc::Output) -> anyhow::Result<()> {
+        match output {
+            jsonrpc::Output::Success(jsonrpc::Success { id, result, .. }) => {
+                println!("<- {}", result);
+
+                let tx = self
+                    .pending_requests
+                    .remove(&id)
+                    .expect("pending_request with id not found!");
+                tx.send(Ok(result)).await?;
+            }
+            jsonrpc::Output::Failure(_) => panic!("recv fail"),
+            msg => unimplemented!("{:?}", msg),
+        }
+        Ok(())
+    }
+
+    pub async fn duplex(mut self) {
+        loop {
+            select! {
+                // client -> server
+                msg = self.outgoing.next().fuse() => {
+                    if msg.is_none() {
+                        break;
+                    }
+                    let msg = msg.unwrap();
+
+                    self.send_payload(msg).await.unwrap();
+                }
+                // server <- client
+                msg = Self::recv(&mut self.reader, &mut self.headers).fuse() => {
+                    if msg.is_err() {
+                        break;
+                    }
+                    let msg = msg.unwrap();
+
+                    match msg {
+                        Message::Output(output) => self.recv_response(output).await.unwrap(),
+                        Message::Notification(_) => {
+                            // dispatch
+                        }
+                        Message::Call(_) => {
+                            // dispatch
+                        }
+                    };
+                }
+            }
+        }
+    }
 }
diff --git a/helix-term/Cargo.toml b/helix-term/Cargo.toml
index ed546090..aa91a095 100644
--- a/helix-term/Cargo.toml
+++ b/helix-term/Cargo.toml
@@ -14,6 +14,7 @@ path = "src/main.rs"
 [dependencies]
 helix-core = { path = "../helix-core" }
 helix-view = { path = "../helix-view", features = ["term"]}
+helix-lsp = { path = "../helix-lsp"}
 
 anyhow = "1"
 
diff --git a/helix-term/src/main.rs b/helix-term/src/main.rs
index e14a328f..c35c84d2 100644
--- a/helix-term/src/main.rs
+++ b/helix-term/src/main.rs
@@ -26,9 +26,14 @@ fn main() -> Result<(), Error> {
         std::thread::spawn(move || smol::block_on(EX.run(smol::future::pending::<()>())));
     }
 
-    smol::block_on(EX.run(async {
-        Application::new(args).unwrap().run().await;
-    }));
+    let mut lsp = helix_lsp::Client::start(&EX, "rust-analyzer", &[]);
+
+    smol::block_on(async {
+        let res = lsp.initialize().await;
+        // Application::new(args).unwrap().run().await;
+
+        loop {}
+    });
 
     Ok(())
 }

From 13cb442850ac3cd4b884a62711f0eb8740270d74 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Mon, 19 Oct 2020 16:09:44 +0900
Subject: [PATCH 03/23] wip: Fetching diagnostics, parsing notifications.

---
 Cargo.lock                 |  21 ++--
 helix-lsp/Cargo.toml       |   2 +
 helix-lsp/log              |  45 +++++++
 helix-lsp/src/lib.rs       | 245 ++++++++++---------------------------
 helix-lsp/src/transport.rs | 189 ++++++++++++++++++++++++++++
 helix-term/src/main.rs     |   6 +-
 6 files changed, 317 insertions(+), 191 deletions(-)
 create mode 100644 helix-lsp/log
 create mode 100644 helix-lsp/src/transport.rs

diff --git a/Cargo.lock b/Cargo.lock
index 999a55b1..c4beee76 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -128,9 +128,9 @@ dependencies = [
 
 [[package]]
 name = "async-task"
-version = "4.0.2"
+version = "4.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ab27c1aa62945039e44edaeee1dc23c74cc0c303dd5fe0fb462a184f1c3a518"
+checksum = "e91831deabf0d6d7ec49552e489aed63b7456a7a3c46cff62adad428110b0af0"
 
 [[package]]
 name = "atomic-waker"
@@ -446,6 +446,7 @@ dependencies = [
  "anyhow",
  "futures-util",
  "glob",
+ "helix-core",
  "jsonrpc-core",
  "lsp-types",
  "pathdiff",
@@ -767,9 +768,9 @@ checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 
 [[package]]
 name = "polling"
-version = "2.0.1"
+version = "2.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ab773feb154f12c49ffcfd66ab8bdcf9a1843f950db48b0d8be9d4393783b058"
+checksum = "a2a7bc6b2a29e632e45451c941832803a18cce6781db04de8a04696cdca8bde4"
 dependencies = [
  "cfg-if",
  "libc",
@@ -878,18 +879,18 @@ checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
 [[package]]
 name = "serde"
-version = "1.0.116"
+version = "1.0.117"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "96fe57af81d28386a513cbc6858332abc6117cfdb5999647c6444b8f43a370a5"
+checksum = "b88fa983de7720629c9387e9f517353ed404164b1e482c970a90c1a4aaf7dc1a"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.116"
+version = "1.0.117"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f630a6370fd8e457873b4bd2ffdae75408bc291ba72be773772a4c2a065d9ae8"
+checksum = "cbd1ae72adb44aab48f325a02444a5fc079349a8d804c1fc922aed3f7454c74e"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -992,9 +993,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.44"
+version = "1.0.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e03e57e4fcbfe7749842d53e24ccb9aa12b7252dbe5e91d2acad31834c8b8fdd"
+checksum = "ea9c5432ff16d6152371f808fb5a871cd67368171b09bb21b43df8e4a47a3556"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/helix-lsp/Cargo.toml b/helix-lsp/Cargo.toml
index 1942fc24..b34c139f 100644
--- a/helix-lsp/Cargo.toml
+++ b/helix-lsp/Cargo.toml
@@ -7,6 +7,8 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+helix-core = { path = "../helix-core" }
+
 lsp-types = { version = "0.82", features = ["proposed"] }
 smol = "1.2"
 url = "2"
diff --git a/helix-lsp/log b/helix-lsp/log
new file mode 100644
index 00000000..d8370f16
--- /dev/null
+++ b/helix-lsp/log
@@ -0,0 +1,45 @@
+Sun Oct 18 21:15:33 2020:["lsp#register_server", "server registered", "typescript-language-server"]
+Sun Oct 18 21:15:33 2020:["lsp#register_server", "server registered", "elixir-ls"]
+Sun Oct 18 21:15:33 2020:["lsp#register_server", "server registered", "vue-language-server"]
+Sun Oct 18 21:15:33 2020:["lsp#register_server", "server registered", "rust-analyzer"]
+Sun Oct 18 21:15:33 2020:["s:on_text_document_did_open()", 1, "", "/Users/speed/src/helix/helix-lsp", ""]
+Sun Oct 18 21:15:34 2020:["s:on_text_document_did_close()", 1]
+Sun Oct 18 21:15:34 2020:["s:on_text_document_did_open()", 1, "rust", "/Users/speed/src/helix", "file:///Users/speed/src/helix/helix-lsp/src/lib.rs"]
+Sun Oct 18 21:15:34 2020:["Starting server", "rust-analyzer", ["rust-analyzer"]]
+Sun Oct 18 21:15:34 2020:[{"response": {"data": {"__data__": "vim-lsp", "lsp_id": 7, "server_name": "rust-analyzer"}, "message": "started lsp server successfully"}}]
+Sun Oct 18 21:15:34 2020:["--->", 7, "rust-analyzer", {"method": "initialize", "params": {"rootUri": "file:///Users/speed/src/helix/helix-lsp", "capabilities": {"workspace": {"configuration": true, "applyEdit": true}, "textDocument": {"implementation": {"linkSupport": true}, "documentSymbol": {"symbolKind": {"valueSet": [10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 1, 2, 3, 4, 5, 6, 7, 8, 9]}, "hierarchicalDocumentSymbolSupport": false}, "semanticHighlightingCapabilities": {"semanticHighlighting": false}, "codeAction": {"codeActionLiteralSupport": {"codeActionKind": {"valueSet": ["", "quickfix", "refactor", "refactor.extract", "refactor.inline", "refactor.rewrite", "source", "source.organizeImports"]}}, "dynamicRegistration": false}, "completion": {"completionItem": {"snippetSupport": false, "documentationFormat": ["plaintext"]}, "completionItemKind": {"valueSet": [10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 1, 2, 3, 4, 5, 6, 7, 8, 9]}}, "foldingRange": {"lineFoldingOnly": true}, "typeDefinition": {"linkSupport": true}, "typeHierarchy": false, "declaration": {"linkSupport": true}, "definition": {"linkSupport": true}}}, "rootPath": "/Users/speed/src/helix/helix-lsp", "processId": 22973, "trace": "off"}}]
+Sun Oct 18 21:15:34 2020:["<---", 7, "rust-analyzer", {"response": {"id": 1, "jsonrpc": "2.0", "result": {"capabilities": {"documentHighlightProvider": true, "hoverProvider": true, "typeDefinitionProvider": true, "workspaceSymbolProvider": true, "referencesProvider": true, "signatureHelpProvider": {"triggerCharacters": ["(", ","]}, "foldingRangeProvider": true, "callHierarchyProvider": true, "codeActionProvider": {"codeActionKinds": ["", "quickfix", "refactor", "refactor.extract", "refactor.inline", "refactor.rewrite"]}, "textDocumentSync": {"save": {}, "change": 2, "openClose": true}, "codeLensProvider": {"resolveProvider": true}, "implementationProvider": true, "documentOnTypeFormattingProvider": {"moreTriggerCharacter": [".", ">"], "firstTriggerCharacter": "="}, "definitionProvider": true, "selectionRangeProvider": true, "semanticTokensProvider": {"legend": {"tokenTypes": ["comment", "keyword", "string", "number", "regexp", "operator", "namespace", "type", "struct", "class", "interface", "enum", "typeParameter", "function", "member", "property", "macro", "variable", "parameter", "label", "attribute", "boolean", "builtinType", "enumMember", "escapeSequence", "formatSpecifier", "generic", "lifetime", "punctuation", "selfKeyword", "typeAlias", "union", "unresolvedReference"], "tokenModifiers": ["documentation", "declaration", "definition", "static", "abstract", "deprecated", "readonly", "constant", "controlFlow", "injected", "mutable", "unsafe", "attribute"]}, "documentProvider": true, "rangeProvider": true}, "documentFormattingProvider": true, "documentSymbolProvider": true, "experimental": {"parentModule": true, "onEnter": true, "runnables": {"kinds": ["cargo"]}, "ssr": true, "joinLines": true}, "renameProvider": {"prepareProvider": true}, "completionProvider": {"triggerCharacters": [":", "."]}}, "serverInfo": {"version": "???????", "name": "rust-analyzer"}}}, "request": {"id": 1, "jsonrpc": "2.0", "method": "initialize", "params": {"rootUri": "file:///Users/speed/src/helix/helix-lsp", "capabilities": {"workspace": {"configuration": true, "applyEdit": true}, "textDocument": {"implementation": {"linkSupport": true}, "documentSymbol": {"symbolKind": {"valueSet": [10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 1, 2, 3, 4, 5, 6, 7, 8, 9]}, "hierarchicalDocumentSymbolSupport": false}, "semanticHighlightingCapabilities": {"semanticHighlighting": false}, "codeAction": {"codeActionLiteralSupport": {"codeActionKind": {"valueSet": ["", "quickfix", "refactor", "refactor.extract", "refactor.inline", "refactor.rewrite", "source", "source.organizeImports"]}}, "dynamicRegistration": false}, "completion": {"completionItem": {"snippetSupport": false, "documentationFormat": ["plaintext"]}, "completionItemKind": {"valueSet": [10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 1, 2, 3, 4, 5, 6, 7, 8, 9]}}, "foldingRange": {"lineFoldingOnly": true}, "typeDefinition": {"linkSupport": true}, "typeHierarchy": false, "declaration": {"linkSupport": true}, "definition": {"linkSupport": true}}}, "rootPath": "/Users/speed/src/helix/helix-lsp", "processId": 22973, "trace": "off"}}}]
+Sun Oct 18 21:15:34 2020:["--->", 7, "rust-analyzer", {"method": "initialized", "params": {}}]
+Sun Oct 18 21:15:34 2020:[{"response": {"data": {"__data__": "vim-lsp", "server_name": "rust-analyzer"}, "message": "configuration sent"}}]
+Sun Oct 18 21:15:34 2020:["s:update_file_content()", 1]
+Sun Oct 18 21:15:34 2020:["--->", 7, "rust-analyzer", {"method": "textDocument/didOpen", "params": {"textDocument": {"uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1, "languageId": "rust", "text": "use std::collections::HashMap;\n\nuse jsonrpc_core as jsonrpc;\nuse lsp_types as lsp;\n\nuse serde::{Deserialize, Serialize};\nuse serde_json::Value;\n\nuse smol::channel::{Receiver, Sender};\nuse smol::io::{BufReader, BufWriter};\nuse smol::prelude::*;\nuse smol::process::{Child, ChildStderr, ChildStdin, ChildStdout, Command, Stdio};\nuse smol::Executor;\n\nuse futures_util::{select, FutureExt};\n\n/// A type representing all possible values sent from the server to the client.\n#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]\n#[serde(deny_unknown_fields)]\n#[serde(untagged)]\nenum Message {\n    /// A regular JSON-RPC request output (single response).\n    Output(jsonrpc::Output),\n    /// A notification.\n    Notification(jsonrpc::Notification),\n    /// A JSON-RPC request\n    Call(jsonrpc::Call),\n}\n\npub struct Client {\n    process: Child,\n    stderr: BufReader<ChildStderr>,\n    outgoing: Sender<Payload>,\n\n    pub request_counter: u64,\n\n    capabilities: Option<lsp::ServerCapabilities>,\n}\n\nimpl Client {\n    pub fn start(ex: &Executor, cmd: &str, args: &[String]) -> Self {\n        let mut process = Command::new(cmd)\n            .args(args)\n            .stdin(Stdio::piped())\n            .stdout(Stdio::piped())\n            .stderr(Stdio::piped())\n            .spawn()\n            .expect(\"Failed to start language server\");\n        // smol makes sure the process is reaped on drop, but using kill_on_drop(true) maybe?\n\n        // TODO: do we need bufreader/writer here? or do we use async wrappers on unblock?\n        let writer = BufWriter::new(process.stdin.take().expect(\"Failed to open stdin\"));\n        let reader = BufReader::new(process.stdout.take().expect(\"Failed to open stdout\"));\n        let stderr = BufReader::new(process.stderr.take().expect(\"Failed to open stderr\"));\n\n        let (incoming, outgoing) = Transport::start(ex, reader, writer);\n\n        Client {\n            process,\n            stderr,\n            outgoing,\n\n            request_counter: 0,\n\n            capabilities: None,\n        }\n    }\n\n    fn next_request_id(&mut self) -> jsonrpc::Id {\n        let id = jsonrpc::Id::Num(self.request_counter);\n        self.request_counter += 1;\n        id\n    }\n\n    fn to_params(value: Value) -> anyhow::Result<jsonrpc::Params> {\n        use jsonrpc::Params;\n\n        let params = match value {\n            Value::Null => Params::None,\n            Value::Bool(_) | Value::Number(_) | Value::String(_) => Params::Array(vec![value]),\n            Value::Array(vec) => Params::Array(vec),\n            Value::Object(map) => Params::Map(map),\n        };\n\n        Ok(params)\n    }\n\n    pub async fn request<R: lsp::request::Request>(\n        &mut self,\n        params: R::Params,\n    ) -> anyhow::Result<R::Result>\n    where\n        R::Params: serde::Serialize,\n        R::Result: core::fmt::Debug, // TODO: temporary\n    {\n        let params = serde_json::to_value(params)?;\n\n        let request = jsonrpc::MethodCall {\n            jsonrpc: Some(jsonrpc::Version::V2),\n            id: self.next_request_id(),\n            method: R::METHOD.to_string(),\n            params: Self::to_params(params)?,\n        };\n\n        let (tx, rx) = smol::channel::bounded::<anyhow::Result<Value>>(1);\n\n        self.outgoing\n            .send(Payload::Request {\n                chan: tx,\n                value: request,\n            })\n            .await?;\n\n        let response = rx.recv().await??;\n\n        let response = serde_json::from_value(response)?;\n\n        // TODO: we should pass request to a sender thread via a channel\n        // so it can't be interleaved\n\n        // TODO: responses can be out of order, we need to register a single shot response channel\n\n        Ok(response)\n    }\n\n    pub async fn notify<R: lsp::notification::Notification>(\n        &mut self,\n        params: R::Params,\n    ) -> anyhow::Result<()>\n    where\n        R::Params: serde::Serialize,\n    {\n        let params = serde_json::to_value(params)?;\n\n        let notification = jsonrpc::Notification {\n            jsonrpc: Some(jsonrpc::Version::V2),\n            method: R::METHOD.to_string(),\n            params: Self::to_params(params)?,\n        };\n\n        self.outgoing\n            .send(Payload::Notification(notification))\n            .await?;\n\n        Ok(())\n    }\n\n    // -------------------------------------------------------------------------------------------\n    // General messages\n    // -------------------------------------------------------------------------------------------\n\n    pub async fn initialize(&mut self) -> anyhow::Result<()> {\n        // TODO: delay any requests that are triggered prior to initialize\n\n        #[allow(deprecated)]\n        let params = lsp::InitializeParams {\n            process_id: Some(u64::from(std::process::id())),\n            root_path: None,\n            // root_uri: Some(lsp_types::Url::parse(\"file://localhost/\")?),\n            root_uri: None, // set to project root in the future\n            initialization_options: None,\n            capabilities: lsp::ClientCapabilities::default(),\n            trace: None,\n            workspace_folders: None,\n            client_info: None,\n        };\n\n        let response = self.request::<lsp::request::Initialize>(params).await?;\n        self.capabilities = Some(response.capabilities);\n\n        // next up, notify<initialized>\n        self.notify::<lsp::notification::Initialized>(lsp::InitializedParams {})\n            .await?;\n\n        Ok(())\n    }\n\n    pub async fn shutdown(&mut self) -> anyhow::Result<()> {\n        self.request::<lsp::request::Shutdown>(()).await\n    }\n\n    pub async fn exit(&mut self) -> anyhow::Result<()> {\n        self.notify::<lsp::notification::Exit>(()).await\n    }\n\n    // -------------------------------------------------------------------------------------------\n    // Text document\n    // -------------------------------------------------------------------------------------------\n\n    pub async fn text_document_did_open(\n        &mut self,\n        state: &helix_core::State,\n    ) -> anyhow::Result<()> {\n        self.notify::<lsp::notification::DidOpenTextDocument>(lsp::DidOpenTextDocumentParams {\n            text_document: lsp::TextDocumentItem {\n                uri: lsp::Url::from_file_path(\n                    std::fs::canonicalize(state.path.as_ref().unwrap()).unwrap(),\n                )\n                .unwrap(),\n                language_id: \"rust\".to_string(), // TODO: hardcoded for now\n                version: 0,\n                text: String::from(&state.doc),\n            },\n        })\n        .await\n    }\n\n    // TODO: trigger any time history.commit_revision happens\n    pub async fn text_document_did_change(\n        &mut self,\n        state: &helix_core::State,\n    ) -> anyhow::Result<()> {\n        self.notify::<lsp::notification::DidSaveTextDocument>(lsp::DidSaveTextDocumentParams {\n            text_document: lsp::TextDocumentIdentifier::new(\n                lsp::Url::from_file_path(state.path.as_ref().unwrap()).unwrap(),\n            ),\n            text: None, // TODO?\n        })\n        .await\n    }\n\n    pub async fn text_document_did_close(&mut self) -> anyhow::Result<()> {\n        unimplemented!()\n    }\n\n    // will_save / will_save_wait_until\n\n    pub async fn text_document_did_save(&mut self) -> anyhow::Result<()> {\n        unimplemented!()\n    }\n}\n\nenum Payload {\n    Request {\n        chan: Sender<anyhow::Result<Value>>,\n        value: jsonrpc::MethodCall,\n    },\n    Notification(jsonrpc::Notification),\n}\n\nstruct Transport {\n    incoming: Sender<Message>,\n    outgoing: Receiver<Payload>,\n\n    pending_requests: HashMap<jsonrpc::Id, Sender<anyhow::Result<Value>>>,\n    headers: HashMap<String, String>,\n\n    writer: BufWriter<ChildStdin>,\n    reader: BufReader<ChildStdout>,\n}\n\nimpl Transport {\n    pub fn start(\n        ex: &Executor,\n        reader: BufReader<ChildStdout>,\n        writer: BufWriter<ChildStdin>,\n    ) -> (Receiver<Message>, Sender<Payload>) {\n        let (incoming, rx) = smol::channel::unbounded();\n        let (tx, outgoing) = smol::channel::unbounded();\n\n        let transport = Self {\n            reader,\n            writer,\n            incoming,\n            outgoing,\n            pending_requests: Default::default(),\n            headers: Default::default(),\n        };\n\n        ex.spawn(transport.duplex()).detach();\n\n        (rx, tx)\n    }\n\n    async fn recv(\n        reader: &mut (impl AsyncBufRead + Unpin),\n        headers: &mut HashMap<String, String>,\n    ) -> Result<Message, std::io::Error> {\n        // read headers\n        loop {\n            let mut header = String::new();\n            // detect pipe closed if 0\n            reader.read_line(&mut header).await?;\n            let header = header.trim();\n\n            if header.is_empty() {\n                break;\n            }\n\n            let parts: Vec<&str> = header.split(\": \").collect();\n            if parts.len() != 2 {\n                // return Err(Error::new(ErrorKind::Other, \"Failed to parse header\"));\n                panic!()\n            }\n            headers.insert(parts[0].to_string(), parts[1].to_string());\n        }\n\n        // find content-length\n        let content_length = headers.get(\"Content-Length\").unwrap().parse().unwrap();\n\n        let mut content = vec![0; content_length];\n        reader.read_exact(&mut content).await?;\n        let msg = String::from_utf8(content).unwrap();\n\n        // read data\n\n        // try parsing as output (server response) or call (server request)\n        let output: serde_json::Result<Message> = serde_json::from_str(&msg);\n\n        Ok(output?)\n    }\n\n    pub async fn send_payload(&mut self, payload: Payload) -> anyhow::Result<()> {\n        match payload {\n            Payload::Request { chan, value } => {\n                self.pending_requests.insert(value.id.clone(), chan);\n\n                let json = serde_json::to_string(&value)?;\n                self.send(json).await\n            }\n            Payload::Notification(value) => {\n                let json = serde_json::to_string(&value)?;\n                self.send(json).await\n            }\n        }\n    }\n\n    pub async fn send(&mut self, request: String) -> anyhow::Result<()> {\n        println!(\"-> {}\", request);\n\n        // send the headers\n        self.writer\n            .write_all(format!(\"Content-Length: {}\\r\\n\\r\\n\", request.len()).as_bytes())\n            .await?;\n\n        // send the body\n        self.writer.write_all(request.as_bytes()).await?;\n\n        self.writer.flush().await?;\n\n        Ok(())\n    }\n\n    pub async fn recv_response(&mut self, output: jsonrpc::Output) -> anyhow::Result<()> {\n        match output {\n            jsonrpc::Output::Success(jsonrpc::Success { id, result, .. }) => {\n                println!(\"<- {}\", result);\n\n                let tx = self\n                    .pending_requests\n                    .remove(&id)\n                    .expect(\"pending_request with id not found!\");\n                tx.send(Ok(result)).await?;\n            }\n            jsonrpc::Output::Failure(_) => panic!(\"recv fail\"),\n            msg => unimplemented!(\"{:?}\", msg),\n        }\n        Ok(())\n    }\n\n    pub async fn duplex(mut self) {\n        loop {\n            select! {\n                // client -> server\n                msg = self.outgoing.next().fuse() => {\n                    if msg.is_none() {\n                        break;\n                    }\n                    let msg = msg.unwrap();\n\n                    self.send_payload(msg).await.unwrap();\n                }\n                // server <- client\n                msg = Self::recv(&mut self.reader, &mut self.headers).fuse() => {\n                    if msg.is_err() {\n                        break;\n                    }\n                    let msg = msg.unwrap();\n\n                    match msg {\n                        Message::Output(output) => self.recv_response(output).await.unwrap(),\n                        Message::Notification(_) => {\n                            // dispatch\n                        }\n                        Message::Call(_) => {\n                            // dispatch\n                        }\n                    };\n                }\n            }\n        }\n    }\n}\n"}}}]
+Sun Oct 18 21:15:34 2020:[{"response": {"data": {"__data__": "vim-lsp", "server_name": "rust-analyzer"}, "message": "server already started"}}]
+Sun Oct 18 21:15:34 2020:[{"response": {"data": {"__data__": "vim-lsp", "init_result": {"id": 1, "jsonrpc": "2.0", "result": {"capabilities": {"documentHighlightProvider": true, "hoverProvider": true, "typeDefinitionProvider": true, "workspaceSymbolProvider": true, "referencesProvider": true, "signatureHelpProvider": {"triggerCharacters": ["(", ","]}, "foldingRangeProvider": true, "callHierarchyProvider": true, "codeActionProvider": {"codeActionKinds": ["", "quickfix", "refactor", "refactor.extract", "refactor.inline", "refactor.rewrite"]}, "textDocumentSync": {"save": {}, "change": 2, "openClose": true}, "codeLensProvider": {"resolveProvider": true}, "implementationProvider": true, "documentOnTypeFormattingProvider": {"moreTriggerCharacter": [".", ">"], "firstTriggerCharacter": "="}, "definitionProvider": true, "selectionRangeProvider": true, "semanticTokensProvider": {"legend": {"tokenTypes": ["comment", "keyword", "string", "number", "regexp", "operator", "namespace", "type", "struct", "class", "interface", "enum", "typeParameter", "function", "member", "property", "macro", "variable", "parameter", "label", "attribute", "boolean", "builtinType", "enumMember", "escapeSequence", "formatSpecifier", "generic", "lifetime", "punctuation", "selfKeyword", "typeAlias", "union", "unresolvedReference"], "tokenModifiers": ["documentation", "declaration", "definition", "static", "abstract", "deprecated", "readonly", "constant", "controlFlow", "injected", "mutable", "unsafe", "attribute"]}, "documentProvider": true, "rangeProvider": true}, "documentFormattingProvider": true, "documentSymbolProvider": true, "experimental": {"parentModule": true, "onEnter": true, "runnables": {"kinds": ["cargo"]}, "ssr": true, "joinLines": true}, "renameProvider": {"prepareProvider": true}, "completionProvider": {"triggerCharacters": [":", "."]}}, "serverInfo": {"version": "???????", "name": "rust-analyzer"}}}, "server_name": "rust-analyzer"}, "message": "lsp server already initialized"}}]
+Sun Oct 18 21:15:34 2020:[{"response": {"data": {"__data__": "vim-lsp", "server_name": "rust-analyzer"}, "message": "configuration sent"}}]
+Sun Oct 18 21:15:34 2020:[{"response": {"data": {"path": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "__data__": "vim-lsp", "server_name": "rust-analyzer"}, "message": "already opened"}}]
+Sun Oct 18 21:15:34 2020:[{"response": {"data": {"path": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "__data__": "vim-lsp", "server_name": "rust-analyzer"}, "message": "not dirty"}}]
+Sun Oct 18 21:15:34 2020:["--->", 7, "rust-analyzer", {"method": "textDocument/foldingRange", "on_notification": "---funcref---", "bufnr": 1, "params": {"textDocument": {"uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs"}}, "sync": 0}]
+Sun Oct 18 21:15:34 2020:[{"response": {"data": {"path": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "__data__": "vim-lsp", "filetype": "rust", "server_name": "rust-analyzer"}, "message": "textDocument/open sent"}}]
+Sun Oct 18 21:15:34 2020:[{"response": {"data": {"path": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "__data__": "vim-lsp", "server_name": "rust-analyzer"}, "message": "not dirty"}}]
+Sun Oct 18 21:15:35 2020:["<---", 7, {"id": 0, "jsonrpc": "2.0", "method": "client/registerCapability", "params": {"registrations": [{"id": "textDocument/didSave", "registerOptions": {"includeText": false, "documentSelector": [{"pattern": "**/*.rs"}, {"pattern": "**/Cargo.toml"}, {"pattern": "**/Cargo.lock"}]}, "method": "textDocument/didSave"}]}}]
+Sun Oct 18 21:15:35 2020:["--->", 7, "rust-analyzer", {"id": 0, "error": {"code": -32601, "message": "Method not found"}}]
+Sun Oct 18 21:15:35 2020:["<---", 7, "rust-analyzer", {"response": {"id": 2, "jsonrpc": "2.0", "result": [{"startLine": 2, "kind": "imports", "endLine": 3}, {"startLine": 5, "kind": "imports", "endLine": 6}, {"startLine": 8, "kind": "imports", "endLine": 12}, {"startLine": 20, "endLine": 27}, {"startLine": 29, "endLine": 37}, {"startLine": 39, "endLine": 230}, {"startLine": 40, "endLine": 66}, {"startLine": 57, "endLine": 65}, {"startLine": 68, "endLine": 72}, {"startLine": 74, "endLine": 85}, {"startLine": 77, "endLine": 81}, {"startLine": 87, "endLine": 89}, {"startLine": 94, "endLine": 123}, {"startLine": 97, "endLine": 101}, {"startLine": 107, "endLine": 110}, {"startLine": 107, "endLine": 109}, {"startLine": 117, "kind": "comment", "endLine": 118}, {"startLine": 125, "endLine": 127}, {"startLine": 131, "endLine": 145}, {"startLine": 134, "endLine": 137}, {"startLine": 147, "kind": "comment", "endLine": 149}, {"startLine": 151, "endLine": 175}, {"startLine": 155, "endLine": 164}, {"startLine": 177, "endLine": 179}, {"startLine": 181, "endLine": 183}, {"startLine": 185, "kind": "comment", "endLine": 187}, {"startLine": 189, "endLine": 191}, {"startLine": 192, "endLine": 205}, {"startLine": 193, "endLine": 203}, {"startLine": 193, "endLine": 202}, {"startLine": 194, "endLine": 201}, {"startLine": 195, "endLine": 197}, {"startLine": 208, "endLine": 210}, {"startLine": 211, "endLine": 219}, {"startLine": 212, "endLine": 217}, {"startLine": 212, "endLine": 216}, {"startLine": 213, "endLine": 214}, {"startLine": 221, "endLine": 223}, {"startLine": 227, "endLine": 229}, {"startLine": 232, "endLine": 238}, {"startLine": 233, "endLine": 235}, {"startLine": 240, "endLine": 249}, {"startLine": 251, "endLine": 392}, {"startLine": 252, "endLine": 255}, {"startLine": 256, "endLine": 272}, {"startLine": 260, "endLine": 266}, {"startLine": 274, "endLine": 276}, {"startLine": 277, "endLine": 310}, {"startLine": 279, "endLine": 295}, {"startLine": 285, "endLine": 287}, {"startLine": 290, "endLine": 293}, {"startLine": 312, "endLine": 325}, {"startLine": 313, "endLine": 324}, {"startLine": 314, "endLine": 319}, {"startLine": 320, "endLine": 323}, {"startLine": 327, "endLine": 341}, {"startLine": 343, "endLine": 358}, {"startLine": 344, "endLine": 356}, {"startLine": 345, "endLine": 353}, {"startLine": 360, "endLine": 391}, {"startLine": 361, "endLine": 390}, {"startLine": 362, "endLine": 389}, {"startLine": 364, "endLine": 371}, {"startLine": 365, "endLine": 367}, {"startLine": 373, "endLine": 388}, {"startLine": 374, "endLine": 376}, {"startLine": 379, "endLine": 386}, {"startLine": 381, "endLine": 383}, {"startLine": 384, "endLine": 386}]}, "request": {"id": 2, "jsonrpc": "2.0", "method": "textDocument/foldingRange", "params": {"textDocument": {"uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs"}}}}]
+Sun Oct 18 21:15:36 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "range": {"end": {"character": 15, "line": 355}, "start": {"character": 12, "line": 355}}, "code": "unreachable_patterns", "message": "unreachable pattern\n`#[warn(unreachable_patterns)]` on by default", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1}}}]
+Sun Oct 18 21:15:36 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "tags": [1], "range": {"end": {"character": 28, "line": 618}, "start": {"character": 24, "line": 618}}, "code": "unused_variables", "message": "unused variable: `view`\n`#[warn(unused_variables)]` on by default", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-view/src/commands.rs"}}}]
+Sun Oct 18 21:15:36 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "range": {"end": {"character": 15, "line": 355}, "start": {"character": 12, "line": 355}}, "code": "unreachable_patterns", "message": "unreachable pattern\n`#[warn(unreachable_patterns)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 21, "line": 55}, "start": {"character": 13, "line": 55}}, "code": "unused_variables", "message": "unused variable: `incoming`\n`#[warn(unused_variables)]` on by default", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1}}}]
+Sun Oct 18 21:15:36 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "range": {"end": {"character": 15, "line": 355}, "start": {"character": 12, "line": 355}}, "code": "unreachable_patterns", "message": "unreachable pattern\n`#[warn(unreachable_patterns)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 21, "line": 55}, "start": {"character": 13, "line": 55}}, "code": "unused_variables", "message": "unused variable: `incoming`\n`#[warn(unused_variables)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 18, "line": 30}, "start": {"character": 4, "line": 30}}, "code": "dead_code", "message": "field is never read: `process`\n`#[warn(dead_code)]` on by default", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1}}}]
+Sun Oct 18 21:15:36 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "range": {"end": {"character": 15, "line": 355}, "start": {"character": 12, "line": 355}}, "code": "unreachable_patterns", "message": "unreachable pattern\n`#[warn(unreachable_patterns)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 21, "line": 55}, "start": {"character": 13, "line": 55}}, "code": "unused_variables", "message": "unused variable: `incoming`\n`#[warn(unused_variables)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 18, "line": 30}, "start": {"character": 4, "line": 30}}, "code": "dead_code", "message": "field is never read: `process`\n`#[warn(dead_code)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 34, "line": 31}, "start": {"character": 4, "line": 31}}, "code": "dead_code", "message": "field is never read: `stderr`", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1}}}]
+Sun Oct 18 21:15:36 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "range": {"end": {"character": 15, "line": 355}, "start": {"character": 12, "line": 355}}, "code": "unreachable_patterns", "message": "unreachable pattern\n`#[warn(unreachable_patterns)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 21, "line": 55}, "start": {"character": 13, "line": 55}}, "code": "unused_variables", "message": "unused variable: `incoming`\n`#[warn(unused_variables)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 18, "line": 30}, "start": {"character": 4, "line": 30}}, "code": "dead_code", "message": "field is never read: `process`\n`#[warn(dead_code)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 34, "line": 31}, "start": {"character": 4, "line": 31}}, "code": "dead_code", "message": "field is never read: `stderr`", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 29, "line": 241}, "start": {"character": 4, "line": 241}}, "code": "dead_code", "message": "field is never read: `incoming`", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1}}}]
+Sun Oct 18 21:15:39 2020:["lsp#register_server", "server registered", "typescript-language-server"]
+Sun Oct 18 21:15:39 2020:["lsp#register_server", "server registered", "elixir-ls"]
+Sun Oct 18 21:15:39 2020:["lsp#register_server", "server registered", "vue-language-server"]
+Sun Oct 18 21:15:39 2020:["lsp#register_server", "server registered", "rust-analyzer"]
+Sun Oct 18 21:15:39 2020:["s:on_text_document_did_open()", 1, "vim", "/Users/speed/src/helix/helix-lsp", "file:///Users/speed/.vimrc"]
+Sun Oct 18 21:15:40 2020:["s:on_text_document_did_change()", 1]
+Sun Oct 18 21:15:40 2020:["s:send_didchange_queue() will be triggered"]
+Sun Oct 18 21:15:40 2020:["s:on_text_document_did_change()", 1]
+Sun Oct 18 21:15:41 2020:["s:on_text_document_did_save()", 1]
+Sun Oct 18 21:15:41 2020:["s:on_text_document_did_close()", 1]
+Sun Oct 18 21:15:55 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "range": {"end": {"character": 15, "line": 355}, "start": {"character": 12, "line": 355}}, "code": "unreachable_patterns", "message": "unreachable pattern\n`#[warn(unreachable_patterns)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 21, "line": 55}, "start": {"character": 13, "line": 55}}, "code": "unused_variables", "message": "unused variable: `incoming`\n`#[warn(unused_variables)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 18, "line": 30}, "start": {"character": 4, "line": 30}}, "code": "dead_code", "message": "field is never read: `process`\n`#[warn(dead_code)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 34, "line": 31}, "start": {"character": 4, "line": 31}}, "code": "dead_code", "message": "field is never read: `stderr`", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 29, "line": 241}, "start": {"character": 4, "line": 241}}, "code": "dead_code", "message": "field is never read: `incoming`", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1}}}]
+Sun Oct 18 21:15:57 2020:["s:on_text_document_did_close()", 1]
+Sun Oct 18 21:15:57 2020:["s:on_exit", 7, "rust-analyzer", "exited", 143]
diff --git a/helix-lsp/src/lib.rs b/helix-lsp/src/lib.rs
index b371f337..41b3fdb2 100644
--- a/helix-lsp/src/lib.rs
+++ b/helix-lsp/src/lib.rs
@@ -1,18 +1,22 @@
+mod transport;
+
+use transport::{Payload, Transport};
+
 use std::collections::HashMap;
 
 use jsonrpc_core as jsonrpc;
 use lsp_types as lsp;
-
-use serde::{Deserialize, Serialize};
 use serde_json::Value;
 
-use smol::channel::{Receiver, Sender};
-use smol::io::{BufReader, BufWriter};
-use smol::prelude::*;
-use smol::process::{Child, ChildStderr, ChildStdin, ChildStdout, Command, Stdio};
-use smol::Executor;
+use serde::{Deserialize, Serialize};
 
-use futures_util::{select, FutureExt};
+use smol::prelude::*;
+use smol::{
+    channel::{Receiver, Sender},
+    io::{BufReader, BufWriter},
+    process::{Child, ChildStderr, Command, Stdio},
+    Executor,
+};
 
 /// A type representing all possible values sent from the server to the client.
 #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
@@ -27,14 +31,40 @@ enum Message {
     Call(jsonrpc::Call),
 }
 
+#[derive(Debug, PartialEq, Clone)]
+enum Notification {}
+
+impl Notification {
+    pub fn parse(method: &str, params: jsonrpc::Params) {
+        use lsp::notification::Notification as _;
+
+        match method {
+            lsp::notification::PublishDiagnostics::METHOD => {
+                let params: lsp::PublishDiagnosticsParams = params
+                    .parse()
+                    .expect("Failed to parse PublishDiagnostics params");
+
+                println!("{:?}", params);
+
+                // TODO: need to loop over diagnostics and distinguish them by URI
+            }
+            _ => println!("unhandled notification: {}", method),
+        }
+    }
+}
+
 pub struct Client {
     process: Child,
     stderr: BufReader<ChildStderr>,
+
     outgoing: Sender<Payload>,
+    incoming: Receiver<Message>,
 
     pub request_counter: u64,
 
     capabilities: Option<lsp::ServerCapabilities>,
+    // TODO: handle PublishDiagnostics Version
+    diagnostics: HashMap<lsp::Url, Vec<lsp::Diagnostic>>,
 }
 
 impl Client {
@@ -58,11 +88,14 @@ impl Client {
         Client {
             process,
             stderr,
+
             outgoing,
+            incoming,
 
             request_counter: 0,
 
             capabilities: None,
+            diagnostics: HashMap::new(),
         }
     }
 
@@ -187,19 +220,39 @@ impl Client {
     // Text document
     // -------------------------------------------------------------------------------------------
 
-    pub async fn text_document_did_open(&mut self) -> anyhow::Result<()> {
+    pub async fn text_document_did_open(
+        &mut self,
+        state: &helix_core::State,
+    ) -> anyhow::Result<()> {
         self.notify::<lsp::notification::DidOpenTextDocument>(lsp::DidOpenTextDocumentParams {
             text_document: lsp::TextDocumentItem {
-                uri: lsp::Url::parse(".")?,
-                language_id: "rust".to_string(),
+                uri: lsp::Url::from_file_path(
+                    std::fs::canonicalize(state.path.as_ref().unwrap()).unwrap(),
+                )
+                .unwrap(),
+                language_id: "rust".to_string(), // TODO: hardcoded for now
                 version: 0,
-                text: "".to_string(),
+                text: String::from(&state.doc),
             },
         })
         .await
     }
 
-    pub async fn text_document_did_change(&mut self) -> anyhow::Result<()> {
+    // TODO: trigger any time history.commit_revision happens
+    pub async fn text_document_did_change(
+        &mut self,
+        state: &helix_core::State,
+    ) -> anyhow::Result<()> {
+        self.notify::<lsp::notification::DidSaveTextDocument>(lsp::DidSaveTextDocumentParams {
+            text_document: lsp::TextDocumentIdentifier::new(
+                lsp::Url::from_file_path(state.path.as_ref().unwrap()).unwrap(),
+            ),
+            text: None, // TODO?
+        })
+        .await
+    }
+
+    pub async fn text_document_did_close(&mut self) -> anyhow::Result<()> {
         unimplemented!()
     }
 
@@ -208,170 +261,4 @@ impl Client {
     pub async fn text_document_did_save(&mut self) -> anyhow::Result<()> {
         unimplemented!()
     }
-
-    pub async fn text_document_did_close(&mut self) -> anyhow::Result<()> {
-        unimplemented!()
-    }
-}
-
-enum Payload {
-    Request {
-        chan: Sender<anyhow::Result<Value>>,
-        value: jsonrpc::MethodCall,
-    },
-    Notification(jsonrpc::Notification),
-}
-
-struct Transport {
-    incoming: Sender<Message>,
-    outgoing: Receiver<Payload>,
-
-    pending_requests: HashMap<jsonrpc::Id, Sender<anyhow::Result<Value>>>,
-    headers: HashMap<String, String>,
-
-    writer: BufWriter<ChildStdin>,
-    reader: BufReader<ChildStdout>,
-}
-
-impl Transport {
-    pub fn start(
-        ex: &Executor,
-        reader: BufReader<ChildStdout>,
-        writer: BufWriter<ChildStdin>,
-    ) -> (Receiver<Message>, Sender<Payload>) {
-        let (incoming, rx) = smol::channel::unbounded();
-        let (tx, outgoing) = smol::channel::unbounded();
-
-        let transport = Self {
-            reader,
-            writer,
-            incoming,
-            outgoing,
-            pending_requests: Default::default(),
-            headers: Default::default(),
-        };
-
-        ex.spawn(transport.duplex()).detach();
-
-        (rx, tx)
-    }
-
-    async fn recv(
-        reader: &mut (impl AsyncBufRead + Unpin),
-        headers: &mut HashMap<String, String>,
-    ) -> Result<Message, std::io::Error> {
-        // read headers
-        loop {
-            let mut header = String::new();
-            // detect pipe closed if 0
-            reader.read_line(&mut header).await?;
-            let header = header.trim();
-
-            if header.is_empty() {
-                break;
-            }
-
-            let parts: Vec<&str> = header.split(": ").collect();
-            if parts.len() != 2 {
-                // return Err(Error::new(ErrorKind::Other, "Failed to parse header"));
-                panic!()
-            }
-            headers.insert(parts[0].to_string(), parts[1].to_string());
-        }
-
-        // find content-length
-        let content_length = headers.get("Content-Length").unwrap().parse().unwrap();
-
-        let mut content = vec![0; content_length];
-        reader.read_exact(&mut content).await?;
-        let msg = String::from_utf8(content).unwrap();
-
-        // read data
-
-        // try parsing as output (server response) or call (server request)
-        let output: serde_json::Result<Message> = serde_json::from_str(&msg);
-
-        Ok(output?)
-    }
-
-    pub async fn send_payload(&mut self, payload: Payload) -> anyhow::Result<()> {
-        match payload {
-            Payload::Request { chan, value } => {
-                self.pending_requests.insert(value.id.clone(), chan);
-
-                let json = serde_json::to_string(&value)?;
-                self.send(json).await
-            }
-            Payload::Notification(value) => {
-                let json = serde_json::to_string(&value)?;
-                self.send(json).await
-            }
-        }
-    }
-
-    pub async fn send(&mut self, request: String) -> anyhow::Result<()> {
-        println!("-> {}", request);
-
-        // send the headers
-        self.writer
-            .write_all(format!("Content-Length: {}\r\n\r\n", request.len()).as_bytes())
-            .await?;
-
-        // send the body
-        self.writer.write_all(request.as_bytes()).await?;
-
-        self.writer.flush().await?;
-
-        Ok(())
-    }
-
-    pub async fn recv_response(&mut self, output: jsonrpc::Output) -> anyhow::Result<()> {
-        match output {
-            jsonrpc::Output::Success(jsonrpc::Success { id, result, .. }) => {
-                println!("<- {}", result);
-
-                let tx = self
-                    .pending_requests
-                    .remove(&id)
-                    .expect("pending_request with id not found!");
-                tx.send(Ok(result)).await?;
-            }
-            jsonrpc::Output::Failure(_) => panic!("recv fail"),
-            msg => unimplemented!("{:?}", msg),
-        }
-        Ok(())
-    }
-
-    pub async fn duplex(mut self) {
-        loop {
-            select! {
-                // client -> server
-                msg = self.outgoing.next().fuse() => {
-                    if msg.is_none() {
-                        break;
-                    }
-                    let msg = msg.unwrap();
-
-                    self.send_payload(msg).await.unwrap();
-                }
-                // server <- client
-                msg = Self::recv(&mut self.reader, &mut self.headers).fuse() => {
-                    if msg.is_err() {
-                        break;
-                    }
-                    let msg = msg.unwrap();
-
-                    match msg {
-                        Message::Output(output) => self.recv_response(output).await.unwrap(),
-                        Message::Notification(_) => {
-                            // dispatch
-                        }
-                        Message::Call(_) => {
-                            // dispatch
-                        }
-                    };
-                }
-            }
-        }
-    }
 }
diff --git a/helix-lsp/src/transport.rs b/helix-lsp/src/transport.rs
new file mode 100644
index 00000000..c44ffa91
--- /dev/null
+++ b/helix-lsp/src/transport.rs
@@ -0,0 +1,189 @@
+use std::collections::HashMap;
+
+use crate::{Message, Notification};
+
+use jsonrpc_core as jsonrpc;
+use lsp_types as lsp;
+use serde_json::Value;
+
+use smol::prelude::*;
+
+use smol::{
+    channel::{Receiver, Sender},
+    io::{BufReader, BufWriter},
+    process::{ChildStderr, ChildStdin, ChildStdout},
+    Executor,
+};
+
+pub(crate) enum Payload {
+    Request {
+        chan: Sender<anyhow::Result<Value>>,
+        value: jsonrpc::MethodCall,
+    },
+    Notification(jsonrpc::Notification),
+}
+
+pub(crate) struct Transport {
+    incoming: Sender<Message>,
+    outgoing: Receiver<Payload>,
+
+    pending_requests: HashMap<jsonrpc::Id, Sender<anyhow::Result<Value>>>,
+    headers: HashMap<String, String>,
+
+    writer: BufWriter<ChildStdin>,
+    reader: BufReader<ChildStdout>,
+}
+
+impl Transport {
+    pub fn start(
+        ex: &Executor,
+        reader: BufReader<ChildStdout>,
+        writer: BufWriter<ChildStdin>,
+    ) -> (Receiver<Message>, Sender<Payload>) {
+        let (incoming, rx) = smol::channel::unbounded();
+        let (tx, outgoing) = smol::channel::unbounded();
+
+        let transport = Self {
+            reader,
+            writer,
+            incoming,
+            outgoing,
+            pending_requests: Default::default(),
+            headers: Default::default(),
+        };
+
+        ex.spawn(transport.duplex()).detach();
+
+        (rx, tx)
+    }
+
+    async fn recv(
+        reader: &mut (impl AsyncBufRead + Unpin),
+        headers: &mut HashMap<String, String>,
+    ) -> Result<Message, std::io::Error> {
+        // read headers
+        loop {
+            let mut header = String::new();
+            // detect pipe closed if 0
+            reader.read_line(&mut header).await?;
+            let header = header.trim();
+
+            if header.is_empty() {
+                break;
+            }
+
+            let parts: Vec<&str> = header.split(": ").collect();
+            if parts.len() != 2 {
+                // return Err(Error::new(ErrorKind::Other, "Failed to parse header"));
+                panic!()
+            }
+            headers.insert(parts[0].to_string(), parts[1].to_string());
+        }
+
+        // find content-length
+        let content_length = headers.get("Content-Length").unwrap().parse().unwrap();
+
+        let mut content = vec![0; content_length];
+        reader.read_exact(&mut content).await?;
+        let msg = String::from_utf8(content).unwrap();
+
+        // read data
+
+        // try parsing as output (server response) or call (server request)
+        let output: serde_json::Result<Message> = serde_json::from_str(&msg);
+
+        Ok(output?)
+    }
+
+    pub async fn send_payload(&mut self, payload: Payload) -> anyhow::Result<()> {
+        match payload {
+            Payload::Request { chan, value } => {
+                self.pending_requests.insert(value.id.clone(), chan);
+
+                let json = serde_json::to_string(&value)?;
+                self.send(json).await
+            }
+            Payload::Notification(value) => {
+                let json = serde_json::to_string(&value)?;
+                self.send(json).await
+            }
+        }
+    }
+
+    pub async fn send(&mut self, request: String) -> anyhow::Result<()> {
+        println!("-> {}", request);
+
+        // send the headers
+        self.writer
+            .write_all(format!("Content-Length: {}\r\n\r\n", request.len()).as_bytes())
+            .await?;
+
+        // send the body
+        self.writer.write_all(request.as_bytes()).await?;
+
+        self.writer.flush().await?;
+
+        Ok(())
+    }
+
+    pub async fn recv_msg(&mut self, msg: Message) -> anyhow::Result<()> {
+        match msg {
+            Message::Output(output) => self.recv_response(output).await?,
+            Message::Notification(jsonrpc::Notification { method, params, .. }) => {
+                let notification = Notification::parse(&method, params);
+
+                println!("<- {} {:?}", method, notification);
+                // dispatch
+            }
+            Message::Call(call) => {
+                println!("<- {:?}", call);
+                // dispatch
+            }
+            _ => unreachable!(),
+        };
+        Ok(())
+    }
+
+    pub async fn recv_response(&mut self, output: jsonrpc::Output) -> anyhow::Result<()> {
+        match output {
+            jsonrpc::Output::Success(jsonrpc::Success { id, result, .. }) => {
+                println!("<- {}", result);
+
+                let tx = self
+                    .pending_requests
+                    .remove(&id)
+                    .expect("pending_request with id not found!");
+                tx.send(Ok(result)).await?;
+            }
+            jsonrpc::Output::Failure(_) => panic!("recv fail"),
+            msg => unimplemented!("{:?}", msg),
+        }
+        Ok(())
+    }
+
+    pub async fn duplex(mut self) {
+        use futures_util::{select, FutureExt};
+        loop {
+            select! {
+                // client -> server
+                msg = self.outgoing.next().fuse() => {
+                    if msg.is_none() {
+                        break;
+                    }
+                    let msg = msg.unwrap();
+
+                    self.send_payload(msg).await.unwrap();
+                }
+                // server <- client
+                msg = Self::recv(&mut self.reader, &mut self.headers).fuse() => {
+                    if msg.is_err() {
+                        break;
+                    }
+                    let msg = msg.unwrap();
+
+                    self.recv_msg(msg).await.unwrap();
+                }
+            }
+        }
+    }
+}
diff --git a/helix-term/src/main.rs b/helix-term/src/main.rs
index c35c84d2..07f1ffff 100644
--- a/helix-term/src/main.rs
+++ b/helix-term/src/main.rs
@@ -30,9 +30,11 @@ fn main() -> Result<(), Error> {
 
     smol::block_on(async {
         let res = lsp.initialize().await;
-        // Application::new(args).unwrap().run().await;
-
+        let state = helix_core::State::load("test.rs".into(), &[]).unwrap();
+        let res = lsp.text_document_did_open(&state).await;
         loop {}
+
+        // Application::new(args).unwrap().run().await;
     });
 
     Ok(())

From b2b3083a623ec3dc5e2d1ea9c6ba35970efe19a3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Mon, 19 Oct 2020 16:20:59 +0900
Subject: [PATCH 04/23] Support multiple open views.

---
 helix-term/src/application.rs | 13 +++++--------
 helix-view/src/editor.rs      | 18 +++++++++++++++---
 2 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index 1e719f5f..9c90b6f3 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -354,7 +354,7 @@ impl Application {
     fn render(&mut self) {
         let viewport = Rect::new(OFFSET, 0, self.terminal.size.0, self.terminal.size.1 - 2); // - 2 for statusline and prompt
 
-        if let Some(view) = &mut self.editor.view {
+        if let Some(view) = self.editor.view_mut() {
             self.terminal.render_view(view, viewport);
             if let Some(prompt) = &self.prompt {
                 if prompt.should_close {
@@ -368,11 +368,8 @@ impl Application {
         self.terminal.draw();
 
         // TODO: drop unwrap
-        self.terminal.render_cursor(
-            self.editor.view.as_ref().unwrap(),
-            self.prompt.as_ref(),
-            viewport,
-        );
+        self.terminal
+            .render_cursor(self.editor.view().unwrap(), self.prompt.as_ref(), viewport);
     }
 
     pub async fn event_loop(&mut self) {
@@ -392,7 +389,7 @@ impl Application {
                     self.terminal.resize(width, height);
 
                     // TODO: simplistic ensure cursor in view for now
-                    if let Some(view) = &mut self.editor.view {
+                    if let Some(view) = self.editor.view_mut() {
                         view.size = self.terminal.size;
                         view.ensure_cursor_in_view()
                     };
@@ -408,7 +405,7 @@ impl Application {
                             .handle_input(event, &mut self.editor);
 
                         self.render();
-                    } else if let Some(view) = &mut self.editor.view {
+                    } else if let Some(view) = self.editor.view_mut() {
                         let keys = vec![event];
                         // TODO: sequences (`gg`)
                         // TODO: handle count other than 1
diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index c292caed..08fd1f0c 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -5,20 +5,32 @@ use std::path::PathBuf;
 use anyhow::Error;
 
 pub struct Editor {
-    pub view: Option<View>,
+    pub views: Vec<View>,
+    pub focus: usize,
     pub should_close: bool,
 }
 
 impl Editor {
     pub fn new() -> Self {
         Self {
-            view: None,
+            views: Vec::new(),
+            focus: 0,
             should_close: false,
         }
     }
 
     pub fn open(&mut self, path: PathBuf, size: (u16, u16)) -> Result<(), Error> {
-        self.view = Some(View::open(path, size)?);
+        let pos = self.views.len();
+        self.views.push(View::open(path, size)?);
+        self.focus = pos;
         Ok(())
     }
+
+    pub fn view(&self) -> Option<&View> {
+        self.views.get(self.focus)
+    }
+
+    pub fn view_mut(&mut self) -> Option<&mut View> {
+        self.views.get_mut(self.focus)
+    }
 }

From 64b5b23315f12125a2c5b2f810fe5ac285bdfa79 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Mon, 19 Oct 2020 17:18:03 +0900
Subject: [PATCH 05/23] Move theme from view to editor, support multiple views
 in editor.

---
 helix-core/src/state.rs       |  2 +-
 helix-term/src/application.rs | 30 ++++++++++++++++--------------
 helix-view/src/editor.rs      |  9 ++++++++-
 helix-view/src/lib.rs         |  1 +
 helix-view/src/view.rs        | 16 +++++++---------
 5 files changed, 33 insertions(+), 25 deletions(-)

diff --git a/helix-core/src/state.rs b/helix-core/src/state.rs
index 1b0a67ae..35e20aef 100644
--- a/helix-core/src/state.rs
+++ b/helix-core/src/state.rs
@@ -23,7 +23,7 @@ pub struct State {
 
     pub restore_cursor: bool,
 
-    //
+    // TODO: move these to a Document wrapper?
     pub syntax: Option<Syntax>,
     /// Pending changes since last history commit.
     pub changes: ChangeSet,
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index 9c90b6f3..d65e7e2e 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -1,6 +1,6 @@
 use clap::ArgMatches as Args;
 use helix_core::{indent::TAB_WIDTH, state::Mode, syntax::HighlightEvent, Position, Range, State};
-use helix_view::{commands, keymap, prompt::Prompt, Editor, View};
+use helix_view::{commands, keymap, prompt::Prompt, Editor, Theme, View};
 
 use std::{
     borrow::Cow,
@@ -15,8 +15,7 @@ use anyhow::Error;
 
 use crossterm::{
     cursor,
-    cursor::position,
-    event::{self, read, Event, EventStream, KeyCode, KeyEvent},
+    event::{read, Event, EventStream, KeyCode, KeyEvent},
     execute, queue,
     terminal::{self, disable_raw_mode, enable_raw_mode},
 };
@@ -75,19 +74,18 @@ impl Renderer {
         self.cache = Surface::empty(area);
     }
 
-    pub fn render_view(&mut self, view: &mut View, viewport: Rect) {
-        self.render_buffer(view, viewport);
-        self.render_statusline(view);
+    pub fn render_view(&mut self, view: &mut View, viewport: Rect, theme: &Theme) {
+        self.render_buffer(view, viewport, theme);
+        self.render_statusline(view, theme);
     }
 
     // TODO: ideally not &mut View but highlights require it because of cursor cache
-    pub fn render_buffer(&mut self, view: &mut View, viewport: Rect) {
+    pub fn render_buffer(&mut self, view: &mut View, viewport: Rect, theme: &Theme) {
         let area = Rect::new(0, 0, self.size.0, self.size.1);
         self.surface.reset(); // reset is faster than allocating new empty surface
 
         //  clear with background color
-        self.surface
-            .set_style(area, view.theme.get("ui.background"));
+        self.surface.set_style(area, theme.get("ui.background"));
 
         // TODO: inefficient, should feed chunks.iter() to tree_sitter.parse_with(|offset, pos|)
         let source_code = view.state.doc().to_string();
@@ -150,7 +148,7 @@ impl Renderer {
                     use helix_core::graphemes::{grapheme_width, RopeGraphemes};
 
                     let style = match spans.first() {
-                        Some(span) => view.theme.get(view.theme.scopes()[span.0].as_str()),
+                        Some(span) => theme.get(theme.scopes()[span.0].as_str()),
                         None => Style::default().fg(Color::Rgb(164, 160, 232)), // lavender
                     };
 
@@ -214,7 +212,7 @@ impl Renderer {
                 }
             }
         }
-        let style: Style = view.theme.get("ui.linenr");
+        let style: Style = theme.get("ui.linenr");
         let last_line = view.last_line();
         for (i, line) in (view.first_line..last_line).enumerate() {
             self.surface
@@ -222,7 +220,7 @@ impl Renderer {
         }
     }
 
-    pub fn render_statusline(&mut self, view: &View) {
+    pub fn render_statusline(&mut self, view: &View, theme: &Theme) {
         let mode = match view.state.mode() {
             Mode::Insert => "INS",
             Mode::Normal => "NOR",
@@ -231,7 +229,7 @@ impl Renderer {
         // statusline
         self.surface.set_style(
             Rect::new(0, self.size.1 - 2, self.size.0, 1),
-            view.theme.get("ui.statusline"),
+            theme.get("ui.statusline"),
         );
         self.surface
             .set_string(1, self.size.1 - 2, mode, self.text_color);
@@ -354,8 +352,11 @@ impl Application {
     fn render(&mut self) {
         let viewport = Rect::new(OFFSET, 0, self.terminal.size.0, self.terminal.size.1 - 2); // - 2 for statusline and prompt
 
+        // SAFETY: we cheat around the view_mut() borrow because it doesn't allow us to also borrow
+        // theme. Theme is immutable mutating view won't disrupt theme_ref.
+        let theme_ref = unsafe { &*(&self.editor.theme as *const Theme) };
         if let Some(view) = self.editor.view_mut() {
-            self.terminal.render_view(view, viewport);
+            self.terminal.render_view(view, viewport, theme_ref);
             if let Some(prompt) = &self.prompt {
                 if prompt.should_close {
                     self.prompt = None;
@@ -389,6 +390,7 @@ impl Application {
                     self.terminal.resize(width, height);
 
                     // TODO: simplistic ensure cursor in view for now
+                    // TODO: loop over views
                     if let Some(view) = self.editor.view_mut() {
                         view.size = self.terminal.size;
                         view.ensure_cursor_in_view()
diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index 08fd1f0c..61abd482 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -1,4 +1,6 @@
+use crate::theme::Theme;
 use crate::View;
+use helix_core::State;
 
 use std::path::PathBuf;
 
@@ -8,20 +10,25 @@ pub struct Editor {
     pub views: Vec<View>,
     pub focus: usize,
     pub should_close: bool,
+    pub theme: Theme, // TODO: share one instance
 }
 
 impl Editor {
     pub fn new() -> Self {
+        let theme = Theme::default();
+
         Self {
             views: Vec::new(),
             focus: 0,
             should_close: false,
+            theme,
         }
     }
 
     pub fn open(&mut self, path: PathBuf, size: (u16, u16)) -> Result<(), Error> {
         let pos = self.views.len();
-        self.views.push(View::open(path, size)?);
+        let state = State::load(path, self.theme.scopes())?;
+        self.views.push(View::new(state, size)?);
         self.focus = pos;
         Ok(())
     }
diff --git a/helix-view/src/lib.rs b/helix-view/src/lib.rs
index 8ea634af..9abe8a1a 100644
--- a/helix-view/src/lib.rs
+++ b/helix-view/src/lib.rs
@@ -6,4 +6,5 @@ pub mod theme;
 pub mod view;
 
 pub use editor::Editor;
+pub use theme::Theme;
 pub use view::View;
diff --git a/helix-view/src/view.rs b/helix-view/src/view.rs
index 2b68dbc3..d2a7d556 100644
--- a/helix-view/src/view.rs
+++ b/helix-view/src/view.rs
@@ -1,8 +1,7 @@
 use anyhow::Error;
 
-use std::{borrow::Cow, path::PathBuf};
+use std::borrow::Cow;
 
-use crate::theme::Theme;
 use helix_core::{
     graphemes::{grapheme_width, RopeGraphemes},
     indent::TAB_WIDTH,
@@ -12,24 +11,23 @@ use tui::layout::Rect;
 
 pub const PADDING: usize = 5;
 
+// TODO: view should be View { doc: Document(state, history,..) }
+// since we can have multiple views into the same file
 pub struct View {
     pub state: State,
-    pub history: History,
     pub first_line: usize,
     pub size: (u16, u16),
-    pub theme: Theme, // TODO: share one instance
+
+    // TODO: Doc<> fields
+    pub history: History,
 }
 
 impl View {
-    pub fn open(path: PathBuf, size: (u16, u16)) -> Result<Self, Error> {
-        let theme = Theme::default();
-        let state = State::load(path, theme.scopes())?;
-
+    pub fn new(state: State, size: (u16, u16)) -> Result<Self, Error> {
         let view = Self {
             state,
             first_line: 0,
             size,
-            theme,
             history: History::default(),
         };
 

From f9bfba4d96f80eb41beb91702558f6f165a0e70f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Tue, 20 Oct 2020 13:58:34 +0900
Subject: [PATCH 06/23] Reroute LSP notification events into the main app event
 loop.

---
 Cargo.lock                    |   1 +
 helix-core/src/diagnostic.rs  |   1 +
 helix-core/src/lib.rs         |   2 +
 helix-core/src/state.rs       |  10 +-
 helix-lsp/src/lib.rs          |  33 ++--
 helix-lsp/src/transport.rs    |  14 +-
 helix-term/Cargo.toml         |   2 +
 helix-term/src/application.rs | 279 ++++++++++++++++++++--------------
 helix-term/src/main.rs        |  12 +-
 helix-view/src/keymap.rs      |   4 +-
 helix-view/src/view.rs        |   2 +-
 11 files changed, 206 insertions(+), 154 deletions(-)
 create mode 100644 helix-core/src/diagnostic.rs

diff --git a/Cargo.lock b/Cargo.lock
index c4beee76..2e329fd1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -472,6 +472,7 @@ dependencies = [
  "anyhow",
  "clap",
  "crossterm",
+ "futures-util",
  "helix-core",
  "helix-lsp",
  "helix-view",
diff --git a/helix-core/src/diagnostic.rs b/helix-core/src/diagnostic.rs
new file mode 100644
index 00000000..aee648aa
--- /dev/null
+++ b/helix-core/src/diagnostic.rs
@@ -0,0 +1 @@
+pub struct Diagnostic {}
diff --git a/helix-core/src/lib.rs b/helix-core/src/lib.rs
index 62d23a10..8458c36f 100644
--- a/helix-core/src/lib.rs
+++ b/helix-core/src/lib.rs
@@ -1,4 +1,5 @@
 #![allow(unused)]
+mod diagnostic;
 pub mod graphemes;
 mod history;
 pub mod indent;
@@ -22,6 +23,7 @@ pub use selection::Range;
 pub use selection::Selection;
 pub use syntax::Syntax;
 
+pub use diagnostic::Diagnostic;
 pub use history::History;
 pub use state::State;
 
diff --git a/helix-core/src/state.rs b/helix-core/src/state.rs
index 35e20aef..0f94f696 100644
--- a/helix-core/src/state.rs
+++ b/helix-core/src/state.rs
@@ -1,6 +1,6 @@
 use crate::graphemes::{nth_next_grapheme_boundary, nth_prev_grapheme_boundary, RopeGraphemes};
 use crate::syntax::LOADER;
-use crate::{ChangeSet, Position, Range, Rope, RopeSlice, Selection, Syntax};
+use crate::{ChangeSet, Diagnostic, Position, Range, Rope, RopeSlice, Selection, Syntax};
 use anyhow::Error;
 
 use std::path::PathBuf;
@@ -28,6 +28,8 @@ pub struct State {
     /// Pending changes since last history commit.
     pub changes: ChangeSet,
     pub old_state: Option<(Rope, Selection)>,
+
+    pub diagnostics: Vec<Diagnostic>,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq)]
@@ -58,12 +60,13 @@ impl State {
             syntax: None,
             changes,
             old_state,
+            diagnostics: Vec::new(),
         }
     }
 
     // TODO: passing scopes here is awkward
     pub fn load(path: PathBuf, scopes: &[String]) -> Result<Self, Error> {
-        use std::{env, fs::File, io::BufReader, path::PathBuf};
+        use std::{env, fs::File, io::BufReader};
         let _current_dir = env::current_dir()?;
 
         let doc = Rope::from_reader(BufReader::new(File::open(path.clone())?))?;
@@ -81,7 +84,8 @@ impl State {
             state.syntax = Some(syntax);
         };
 
-        state.path = Some(path);
+        // canonicalize path to absolute value
+        state.path = Some(std::fs::canonicalize(path)?);
 
         Ok(state)
     }
diff --git a/helix-lsp/src/lib.rs b/helix-lsp/src/lib.rs
index 41b3fdb2..3598a594 100644
--- a/helix-lsp/src/lib.rs
+++ b/helix-lsp/src/lib.rs
@@ -2,7 +2,7 @@ mod transport;
 
 use transport::{Payload, Transport};
 
-use std::collections::HashMap;
+// use std::collections::HashMap;
 
 use jsonrpc_core as jsonrpc;
 use lsp_types as lsp;
@@ -32,10 +32,12 @@ enum Message {
 }
 
 #[derive(Debug, PartialEq, Clone)]
-enum Notification {}
+pub enum Notification {
+    PublishDiagnostics(lsp::PublishDiagnosticsParams),
+}
 
 impl Notification {
-    pub fn parse(method: &str, params: jsonrpc::Params) {
+    pub fn parse(method: &str, params: jsonrpc::Params) -> Notification {
         use lsp::notification::Notification as _;
 
         match method {
@@ -44,11 +46,10 @@ impl Notification {
                     .parse()
                     .expect("Failed to parse PublishDiagnostics params");
 
-                println!("{:?}", params);
-
                 // TODO: need to loop over diagnostics and distinguish them by URI
+                Notification::PublishDiagnostics(params)
             }
-            _ => println!("unhandled notification: {}", method),
+            _ => unimplemented!("unhandled notification: {}", method),
         }
     }
 }
@@ -58,13 +59,13 @@ pub struct Client {
     stderr: BufReader<ChildStderr>,
 
     outgoing: Sender<Payload>,
-    incoming: Receiver<Message>,
+    pub incoming: Receiver<Notification>,
 
     pub request_counter: u64,
 
     capabilities: Option<lsp::ServerCapabilities>,
     // TODO: handle PublishDiagnostics Version
-    diagnostics: HashMap<lsp::Url, Vec<lsp::Diagnostic>>,
+    // diagnostics: HashMap<lsp::Url, Vec<lsp::Diagnostic>>,
 }
 
 impl Client {
@@ -95,7 +96,7 @@ impl Client {
             request_counter: 0,
 
             capabilities: None,
-            diagnostics: HashMap::new(),
+            // diagnostics: HashMap::new(),
         }
     }
 
@@ -226,10 +227,7 @@ impl Client {
     ) -> anyhow::Result<()> {
         self.notify::<lsp::notification::DidOpenTextDocument>(lsp::DidOpenTextDocumentParams {
             text_document: lsp::TextDocumentItem {
-                uri: lsp::Url::from_file_path(
-                    std::fs::canonicalize(state.path.as_ref().unwrap()).unwrap(),
-                )
-                .unwrap(),
+                uri: lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
                 language_id: "rust".to_string(), // TODO: hardcoded for now
                 version: 0,
                 text: String::from(&state.doc),
@@ -243,11 +241,12 @@ impl Client {
         &mut self,
         state: &helix_core::State,
     ) -> anyhow::Result<()> {
-        self.notify::<lsp::notification::DidSaveTextDocument>(lsp::DidSaveTextDocumentParams {
-            text_document: lsp::TextDocumentIdentifier::new(
-                lsp::Url::from_file_path(state.path.as_ref().unwrap()).unwrap(),
+        self.notify::<lsp::notification::DidChangeTextDocument>(lsp::DidChangeTextDocumentParams {
+            text_document: lsp::VersionedTextDocumentIdentifier::new(
+                lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
+                0, // TODO: version
             ),
-            text: None, // TODO?
+            content_changes: vec![], // TODO:
         })
         .await
     }
diff --git a/helix-lsp/src/transport.rs b/helix-lsp/src/transport.rs
index c44ffa91..8915a925 100644
--- a/helix-lsp/src/transport.rs
+++ b/helix-lsp/src/transport.rs
@@ -24,7 +24,7 @@ pub(crate) enum Payload {
 }
 
 pub(crate) struct Transport {
-    incoming: Sender<Message>,
+    incoming: Sender<Notification>, // TODO Notification | Call
     outgoing: Receiver<Payload>,
 
     pending_requests: HashMap<jsonrpc::Id, Sender<anyhow::Result<Value>>>,
@@ -39,7 +39,7 @@ impl Transport {
         ex: &Executor,
         reader: BufReader<ChildStdout>,
         writer: BufWriter<ChildStdin>,
-    ) -> (Receiver<Message>, Sender<Payload>) {
+    ) -> (Receiver<Notification>, Sender<Payload>) {
         let (incoming, rx) = smol::channel::unbounded();
         let (tx, outgoing) = smol::channel::unbounded();
 
@@ -111,7 +111,7 @@ impl Transport {
     }
 
     pub async fn send(&mut self, request: String) -> anyhow::Result<()> {
-        println!("-> {}", request);
+        // println!("-> {}", request);
 
         // send the headers
         self.writer
@@ -132,11 +132,11 @@ impl Transport {
             Message::Notification(jsonrpc::Notification { method, params, .. }) => {
                 let notification = Notification::parse(&method, params);
 
-                println!("<- {} {:?}", method, notification);
-                // dispatch
+                // println!("<- {} {:?}", method, notification);
+                self.incoming.send(notification).await?;
             }
             Message::Call(call) => {
-                println!("<- {:?}", call);
+                // println!("<- {:?}", call);
                 // dispatch
             }
             _ => unreachable!(),
@@ -147,7 +147,7 @@ impl Transport {
     pub async fn recv_response(&mut self, output: jsonrpc::Output) -> anyhow::Result<()> {
         match output {
             jsonrpc::Output::Success(jsonrpc::Success { id, result, .. }) => {
-                println!("<- {}", result);
+                // println!("<- {}", result);
 
                 let tx = self
                     .pending_requests
diff --git a/helix-term/Cargo.toml b/helix-term/Cargo.toml
index aa91a095..db1edee9 100644
--- a/helix-term/Cargo.toml
+++ b/helix-term/Cargo.toml
@@ -24,3 +24,5 @@ num_cpus = "1.13"
 tui = { git = "https://github.com/fdehau/tui-rs", default-features = false, features = ["crossterm"] }
 crossterm = { version = "0.18", features = ["event-stream"] }
 clap = { version = "3.0.0-beta.2 ", default-features = false, features = ["std", "cargo"] }
+
+futures-util = "0.3"
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index d65e7e2e..3d5b3459 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -1,6 +1,11 @@
 use clap::ArgMatches as Args;
 use helix_core::{indent::TAB_WIDTH, state::Mode, syntax::HighlightEvent, Position, Range, State};
-use helix_view::{commands, keymap, prompt::Prompt, Editor, Theme, View};
+use helix_view::{
+    commands,
+    keymap::{self, Keymaps},
+    prompt::Prompt,
+    Editor, Theme, View,
+};
 
 use std::{
     borrow::Cow,
@@ -31,14 +36,16 @@ const OFFSET: u16 = 6; // 5 linenr + 1 gutter
 
 type Terminal = tui::Terminal<CrosstermBackend<std::io::Stdout>>;
 
-static EX: smol::Executor = smol::Executor::new();
-
 const BASE_WIDTH: u16 = 30;
 
-pub struct Application {
+pub struct Application<'a> {
     editor: Editor,
     prompt: Option<Prompt>,
     terminal: Renderer,
+
+    keymap: Keymaps,
+    executor: &'a smol::Executor<'a>,
+    lsp: helix_lsp::Client,
 }
 
 struct Renderer {
@@ -235,7 +242,7 @@ impl Renderer {
             .set_string(1, self.size.1 - 2, mode, self.text_color);
     }
 
-    pub fn render_prompt(&mut self, view: &View, prompt: &Prompt) {
+    pub fn render_prompt(&mut self, view: &View, prompt: &Prompt, theme: &Theme) {
         // completion
         if !prompt.completion.is_empty() {
             // TODO: find out better way of clearing individual lines of the screen
@@ -254,7 +261,7 @@ impl Renderer {
             }
             self.surface.set_style(
                 Rect::new(0, self.size.1 - col_height - 2, self.size.0, col_height),
-                view.theme.get("ui.statusline"),
+                theme.get("ui.statusline"),
             );
             for (i, command) in prompt.completion.iter().enumerate() {
                 let color = if prompt.completion_selection_index.is_some()
@@ -330,8 +337,8 @@ impl Renderer {
     }
 }
 
-impl Application {
-    pub fn new(mut args: Args) -> Result<Self, Error> {
+impl<'a> Application<'a> {
+    pub fn new(mut args: Args, executor: &'a smol::Executor<'a>) -> Result<Self, Error> {
         let terminal = Renderer::new()?;
         let mut editor = Editor::new();
 
@@ -339,11 +346,18 @@ impl Application {
             editor.open(file, terminal.size)?;
         }
 
+        let lsp = helix_lsp::Client::start(&executor, "rust-analyzer", &[]);
+
         let mut app = Self {
             editor,
             terminal,
             // TODO; move to state
             prompt: None,
+
+            //
+            keymap: keymap::default(),
+            executor,
+            lsp,
         };
 
         Ok(app)
@@ -361,7 +375,7 @@ impl Application {
                 if prompt.should_close {
                     self.prompt = None;
                 } else {
-                    self.terminal.render_prompt(view, prompt);
+                    self.terminal.render_prompt(view, prompt, theme_ref);
                 }
             }
         }
@@ -375,7 +389,13 @@ impl Application {
 
     pub async fn event_loop(&mut self) {
         let mut reader = EventStream::new();
-        let keymap = keymap::default();
+
+        // initialize lsp
+        let res = self.lsp.initialize().await;
+        let res = self
+            .lsp
+            .text_document_did_open(&self.editor.view().unwrap().state)
+            .await;
 
         self.render();
 
@@ -384,126 +404,149 @@ impl Application {
                 break;
             }
 
-            // Handle key events
-            match reader.next().await {
-                Some(Ok(Event::Resize(width, height))) => {
-                    self.terminal.resize(width, height);
+            use futures_util::{select, FutureExt};
+            select! {
+                event = reader.next().fuse() => {
+                    self.handle_terminal_events(event).await
+                }
+                notification = self.lsp.incoming.next().fuse() => {
+                    self.handle_lsp_notification(notification).await
+                }
+            }
+        }
+    }
 
-                    // TODO: simplistic ensure cursor in view for now
-                    // TODO: loop over views
-                    if let Some(view) = self.editor.view_mut() {
-                        view.size = self.terminal.size;
-                        view.ensure_cursor_in_view()
-                    };
+    pub async fn handle_terminal_events(
+        &mut self,
+        event: Option<Result<Event, crossterm::ErrorKind>>,
+    ) {
+        // Handle key events
+        match event {
+            Some(Ok(Event::Resize(width, height))) => {
+                self.terminal.resize(width, height);
+
+                // TODO: simplistic ensure cursor in view for now
+                // TODO: loop over views
+                if let Some(view) = self.editor.view_mut() {
+                    view.size = self.terminal.size;
+                    view.ensure_cursor_in_view()
+                };
+
+                self.render();
+            }
+            Some(Ok(Event::Key(event))) => {
+                // if there's a prompt, it takes priority
+                if let Some(prompt) = &mut self.prompt {
+                    self.prompt
+                        .as_mut()
+                        .unwrap()
+                        .handle_input(event, &mut self.editor);
 
                     self.render();
-                }
-                Some(Ok(Event::Key(event))) => {
-                    // if there's a prompt, it takes priority
-                    if let Some(prompt) = &mut self.prompt {
-                        self.prompt
-                            .as_mut()
-                            .unwrap()
-                            .handle_input(event, &mut self.editor);
+                } else if let Some(view) = self.editor.view_mut() {
+                    let keys = vec![event];
+                    // TODO: sequences (`gg`)
+                    // TODO: handle count other than 1
+                    match view.state.mode() {
+                        Mode::Insert => {
+                            if let Some(command) = self.keymap[&Mode::Insert].get(&keys) {
+                                command(view, 1);
+                            } else if let KeyEvent {
+                                code: KeyCode::Char(c),
+                                ..
+                            } = event
+                            {
+                                commands::insert::insert_char(view, c);
+                            }
+                            view.ensure_cursor_in_view();
+                        }
+                        Mode::Normal => {
+                            if let &[KeyEvent {
+                                code: KeyCode::Char(':'),
+                                ..
+                            }] = keys.as_slice()
+                            {
+                                let prompt = Prompt::new(
+                                    ":".to_owned(),
+                                    |_input: &str| {
+                                        // TODO: i need this duplicate list right now to avoid borrow checker issues
+                                        let command_list = vec![
+                                            String::from("q"),
+                                            String::from("aaa"),
+                                            String::from("bbb"),
+                                            String::from("ccc"),
+                                            String::from("ddd"),
+                                            String::from("eee"),
+                                            String::from("averylongcommandaverylongcommandaverylongcommandaverylongcommandaverylongcommand"),
+                                            String::from("q"),
+                                            String::from("aaa"),
+                                            String::from("bbb"),
+                                            String::from("ccc"),
+                                            String::from("ddd"),
+                                            String::from("eee"),
+                                            String::from("q"),
+                                            String::from("aaa"),
+                                            String::from("bbb"),
+                                            String::from("ccc"),
+                                            String::from("ddd"),
+                                            String::from("eee"),
+                                            String::from("q"),
+                                            String::from("aaa"),
+                                            String::from("bbb"),
+                                            String::from("ccc"),
+                                            String::from("ddd"),
+                                            String::from("eee"),
+                                            String::from("q"),
+                                            String::from("aaa"),
+                                            String::from("bbb"),
+                                            String::from("ccc"),
+                                            String::from("ddd"),
+                                            String::from("eee"),
+                                        ];
+                                        command_list
+                                            .into_iter()
+                                            .filter(|command| command.contains(_input))
+                                            .collect()
+                                    }, // completion
+                                    |editor: &mut Editor, input: &str| match input {
+                                        "q" => editor.should_close = true,
+                                        _ => (),
+                                    },
+                                );
 
-                        self.render();
-                    } else if let Some(view) = self.editor.view_mut() {
-                        let keys = vec![event];
-                        // TODO: sequences (`gg`)
-                        // TODO: handle count other than 1
-                        match view.state.mode() {
-                            Mode::Insert => {
-                                if let Some(command) = keymap[&Mode::Insert].get(&keys) {
-                                    command(view, 1);
-                                } else if let KeyEvent {
-                                    code: KeyCode::Char(c),
-                                    ..
-                                } = event
-                                {
-                                    commands::insert::insert_char(view, c);
-                                }
+                                self.prompt = Some(prompt);
+
+                            // HAXX: special casing for command mode
+                            } else if let Some(command) = self.keymap[&Mode::Normal].get(&keys) {
+                                command(view, 1);
+
+                                // TODO: simplistic ensure cursor in view for now
                                 view.ensure_cursor_in_view();
                             }
-                            Mode::Normal => {
-                                if let &[KeyEvent {
-                                    code: KeyCode::Char(':'),
-                                    ..
-                                }] = keys.as_slice()
-                                {
-                                    let prompt = Prompt::new(
-                                        ":".to_owned(),
-                                        |_input: &str| {
-                                            // TODO: i need this duplicate list right now to avoid borrow checker issues
-                                            let command_list = vec![
-                                                String::from("q"),
-                                                String::from("aaa"),
-                                                String::from("bbb"),
-                                                String::from("ccc"),
-                                                String::from("ddd"),
-                                                String::from("eee"),
-                                                String::from("averylongcommandaverylongcommandaverylongcommandaverylongcommandaverylongcommand"),
-                                                String::from("q"),
-                                                String::from("aaa"),
-                                                String::from("bbb"),
-                                                String::from("ccc"),
-                                                String::from("ddd"),
-                                                String::from("eee"),
-                                                String::from("q"),
-                                                String::from("aaa"),
-                                                String::from("bbb"),
-                                                String::from("ccc"),
-                                                String::from("ddd"),
-                                                String::from("eee"),
-                                                String::from("q"),
-                                                String::from("aaa"),
-                                                String::from("bbb"),
-                                                String::from("ccc"),
-                                                String::from("ddd"),
-                                                String::from("eee"),
-                                                String::from("q"),
-                                                String::from("aaa"),
-                                                String::from("bbb"),
-                                                String::from("ccc"),
-                                                String::from("ddd"),
-                                                String::from("eee"),
-                                            ];
-                                            command_list
-                                                .into_iter()
-                                                .filter(|command| command.contains(_input))
-                                                .collect()
-                                        }, // completion
-                                        |editor: &mut Editor, input: &str| match input {
-                                            "q" => editor.should_close = true,
-                                            _ => (),
-                                        },
-                                    );
+                        }
+                        mode => {
+                            if let Some(command) = self.keymap[&mode].get(&keys) {
+                                command(view, 1);
 
-                                    self.prompt = Some(prompt);
-
-                                // HAXX: special casing for command mode
-                                } else if let Some(command) = keymap[&Mode::Normal].get(&keys) {
-                                    command(view, 1);
-
-                                    // TODO: simplistic ensure cursor in view for now
-                                    view.ensure_cursor_in_view();
-                                }
-                            }
-                            mode => {
-                                if let Some(command) = keymap[&mode].get(&keys) {
-                                    command(view, 1);
-
-                                    // TODO: simplistic ensure cursor in view for now
-                                    view.ensure_cursor_in_view();
-                                }
+                                // TODO: simplistic ensure cursor in view for now
+                                view.ensure_cursor_in_view();
                             }
                         }
-                        self.render();
                     }
+                    self.render();
                 }
-                Some(Ok(Event::Mouse(_))) => (), // unhandled
-                Some(Err(x)) => panic!(x),
-                None => break,
             }
+            Some(Ok(Event::Mouse(_))) => (), // unhandled
+            Some(Err(x)) => panic!(x),
+            None => panic!(),
+        };
+    }
+
+    pub async fn handle_lsp_notification(&mut self, notification: Option<helix_lsp::Notification>) {
+        use helix_lsp::Notification;
+        match notification {
+            Some(Notification::PublishDiagnostics(params)) => unimplemented!("{:?}", params),
+            _ => unreachable!(),
         }
     }
 
diff --git a/helix-term/src/main.rs b/helix-term/src/main.rs
index 07f1ffff..de3a0175 100644
--- a/helix-term/src/main.rs
+++ b/helix-term/src/main.rs
@@ -26,15 +26,15 @@ fn main() -> Result<(), Error> {
         std::thread::spawn(move || smol::block_on(EX.run(smol::future::pending::<()>())));
     }
 
-    let mut lsp = helix_lsp::Client::start(&EX, "rust-analyzer", &[]);
+    // let mut lsp = helix_lsp::Client::start(&EX, "rust-analyzer", &[]);
 
     smol::block_on(async {
-        let res = lsp.initialize().await;
-        let state = helix_core::State::load("test.rs".into(), &[]).unwrap();
-        let res = lsp.text_document_did_open(&state).await;
-        loop {}
+        // let res = lsp.initialize().await;
+        // let state = helix_core::State::load("test.rs".into(), &[]).unwrap();
+        // let res = lsp.text_document_did_open(&state).await;
+        // loop {}
 
-        // Application::new(args).unwrap().run().await;
+        Application::new(args, &EX).unwrap().run().await;
     });
 
     Ok(())
diff --git a/helix-view/src/keymap.rs b/helix-view/src/keymap.rs
index 69e6cabb..82bdbe21 100644
--- a/helix-view/src/keymap.rs
+++ b/helix-view/src/keymap.rs
@@ -87,8 +87,8 @@ use std::collections::HashMap;
 pub use crossterm::event::{KeyCode, KeyEvent as Key, KeyModifiers as Modifiers};
 
 // TODO: could be trie based
-type Keymap = HashMap<Vec<Key>, Command>;
-type Keymaps = HashMap<state::Mode, Keymap>;
+pub type Keymap = HashMap<Vec<Key>, Command>;
+pub type Keymaps = HashMap<state::Mode, Keymap>;
 
 macro_rules! key {
     ($ch:expr) => {
diff --git a/helix-view/src/view.rs b/helix-view/src/view.rs
index d2a7d556..817714c8 100644
--- a/helix-view/src/view.rs
+++ b/helix-view/src/view.rs
@@ -18,7 +18,7 @@ pub struct View {
     pub first_line: usize,
     pub size: (u16, u16),
 
-    // TODO: Doc<> fields
+    // TODO: Doc fields
     pub history: History,
 }
 

From 49254d7180c8b92be5426cab20914b0343c9282c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Tue, 20 Oct 2020 15:42:53 +0900
Subject: [PATCH 07/23] Total mess but it works: diagnostic marking.

---
 helix-core/src/diagnostic.rs  |  8 +++-
 helix-lsp/src/lib.rs          |  3 ++
 helix-term/src/application.rs | 84 ++++++++++++++++++++++++++++++++---
 helix-view/src/theme.rs       |  2 +
 4 files changed, 91 insertions(+), 6 deletions(-)

diff --git a/helix-core/src/diagnostic.rs b/helix-core/src/diagnostic.rs
index aee648aa..96ed6746 100644
--- a/helix-core/src/diagnostic.rs
+++ b/helix-core/src/diagnostic.rs
@@ -1 +1,7 @@
-pub struct Diagnostic {}
+use crate::Range;
+
+pub struct Diagnostic {
+    pub range: (usize, usize),
+    pub line: usize,
+    pub message: String,
+}
diff --git a/helix-lsp/src/lib.rs b/helix-lsp/src/lib.rs
index 3598a594..939f9927 100644
--- a/helix-lsp/src/lib.rs
+++ b/helix-lsp/src/lib.rs
@@ -10,6 +10,9 @@ use serde_json::Value;
 
 use serde::{Deserialize, Serialize};
 
+pub use lsp::Position;
+pub use lsp::Url;
+
 use smol::prelude::*;
 use smol::{
     channel::{Receiver, Sender},
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index 3d5b3459..5551e26f 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -29,10 +29,10 @@ use tui::{
     backend::CrosstermBackend,
     buffer::Buffer as Surface,
     layout::Rect,
-    style::{Color, Style},
+    style::{Color, Modifier, Style},
 };
 
-const OFFSET: u16 = 6; // 5 linenr + 1 gutter
+const OFFSET: u16 = 7; // 1 diagnostic + 5 linenr + 1 gutter
 
 type Terminal = tui::Terminal<CrosstermBackend<std::io::Stdout>>;
 
@@ -205,6 +205,16 @@ impl Renderer {
                                 style
                             };
 
+                            // ugh, improve with a traverse method
+                            // or interleave highlight spans with selection and diagnostic spans
+                            let style = if view.state.diagnostics.iter().any(|diagnostic| {
+                                diagnostic.range.0 <= char_index && diagnostic.range.1 > char_index
+                            }) {
+                                style.clone().add_modifier(Modifier::UNDERLINED)
+                            } else {
+                                style
+                            };
+
                             // TODO: paint cursor heads except primary
 
                             self.surface
@@ -212,18 +222,23 @@ impl Renderer {
 
                             visual_x += width;
                         }
-                        // if grapheme == "\t"
 
                         char_index += 1;
                     }
                 }
             }
         }
+
         let style: Style = theme.get("ui.linenr");
+        let warning: Style = theme.get("warning");
         let last_line = view.last_line();
         for (i, line) in (view.first_line..last_line).enumerate() {
+            if view.state.diagnostics.iter().any(|d| d.line == line) {
+                self.surface.set_stringn(0, i as u16, "●", 1, warning);
+            }
+
             self.surface
-                .set_stringn(0, i as u16, format!("{:>5}", line + 1), 5, style);
+                .set_stringn(1, i as u16, format!("{:>5}", line + 1), 5, style);
         }
     }
 
@@ -240,6 +255,13 @@ impl Renderer {
         );
         self.surface
             .set_string(1, self.size.1 - 2, mode, self.text_color);
+
+        self.surface.set_string(
+            self.size.0 - 10,
+            self.size.1 - 2,
+            format!("{}", view.state.diagnostics.len()),
+            self.text_color,
+        );
     }
 
     pub fn render_prompt(&mut self, view: &View, prompt: &Prompt, theme: &Theme) {
@@ -545,7 +567,59 @@ impl<'a> Application<'a> {
     pub async fn handle_lsp_notification(&mut self, notification: Option<helix_lsp::Notification>) {
         use helix_lsp::Notification;
         match notification {
-            Some(Notification::PublishDiagnostics(params)) => unimplemented!("{:?}", params),
+            Some(Notification::PublishDiagnostics(params)) => {
+                let view = self.editor.views.iter_mut().find(|view| {
+                    let path = view
+                        .state
+                        .path
+                        .as_ref()
+                        .map(|path| helix_lsp::Url::from_file_path(path).unwrap());
+
+                    eprintln!("{:?} {} {}", path, params.uri, params.diagnostics.len());
+                    // HAXX
+                    path == Some(params.uri.clone())
+                });
+
+                fn lsp_pos_to_pos(doc: &helix_core::RopeSlice, pos: helix_lsp::Position) -> usize {
+                    let line = doc.line_to_char(pos.line as usize);
+                    let line_start = doc.char_to_utf16_cu(line);
+                    doc.utf16_cu_to_char(pos.character as usize + line_start)
+                }
+
+                if let Some(view) = view {
+                    let doc = view.state.doc().slice(..);
+                    let diagnostics = params
+                        .diagnostics
+                        .into_iter()
+                        .map(|diagnostic| {
+                            let start = lsp_pos_to_pos(&doc, diagnostic.range.start);
+                            let end = lsp_pos_to_pos(&doc, diagnostic.range.end);
+
+                            // eprintln!(
+                            //     "{:?}-{:?} {}-{} {}",
+                            //     diagnostic.range.start,
+                            //     diagnostic.range.end,
+                            //     start,
+                            //     end,
+                            //     diagnostic.message
+                            // );
+
+                            helix_core::Diagnostic {
+                                range: (start, end),
+                                line: diagnostic.range.start.line as usize,
+                                message: diagnostic.message,
+                                // severity
+                                // code
+                                // source
+                            }
+                        })
+                        .collect();
+
+                    view.state.diagnostics = diagnostics;
+
+                    self.render();
+                }
+            }
             _ => unreachable!(),
         }
     }
diff --git a/helix-view/src/theme.rs b/helix-view/src/theme.rs
index 4cc399ed..809ec05d 100644
--- a/helix-view/src/theme.rs
+++ b/helix-view/src/theme.rs
@@ -157,6 +157,8 @@ impl Default for Theme {
             "ui.background" => Style::default().bg(Color::Rgb(59, 34, 76)), // midnight
             "ui.linenr" => Style::default().fg(Color::Rgb(90, 89, 119)), // comet
             "ui.statusline" => Style::default().bg(Color::Rgb(40, 23, 51)), // revolver
+
+            "warning" => Style::default().fg(Color::Rgb(255, 205, 28)),
         };
 
         let scopes = mapping.keys().map(ToString::to_string).collect();

From ef5e5f9296d27d11ddfddf6d1c7daf93f9464ddb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Wed, 21 Oct 2020 13:47:20 +0900
Subject: [PATCH 08/23] state.version tracking

---
 helix-core/src/state.rs       |  2 ++
 helix-lsp/src/lib.rs          | 32 +++++++++++++++++++++-----------
 helix-term/src/application.rs | 33 +++++++--------------------------
 helix-view/src/commands.rs    |  7 ++++++-
 4 files changed, 36 insertions(+), 38 deletions(-)

diff --git a/helix-core/src/state.rs b/helix-core/src/state.rs
index 0f94f696..75e5cd40 100644
--- a/helix-core/src/state.rs
+++ b/helix-core/src/state.rs
@@ -29,6 +29,7 @@ pub struct State {
     pub changes: ChangeSet,
     pub old_state: Option<(Rope, Selection)>,
 
+    pub version: i64,
     pub diagnostics: Vec<Diagnostic>,
 }
 
@@ -61,6 +62,7 @@ impl State {
             changes,
             old_state,
             diagnostics: Vec::new(),
+            version: 0,
         }
     }
 
diff --git a/helix-lsp/src/lib.rs b/helix-lsp/src/lib.rs
index 939f9927..f8c73902 100644
--- a/helix-lsp/src/lib.rs
+++ b/helix-lsp/src/lib.rs
@@ -2,6 +2,8 @@ mod transport;
 
 use transport::{Payload, Transport};
 
+use helix_core::{State, Transaction};
+
 // use std::collections::HashMap;
 
 use jsonrpc_core as jsonrpc;
@@ -13,14 +15,24 @@ use serde::{Deserialize, Serialize};
 pub use lsp::Position;
 pub use lsp::Url;
 
-use smol::prelude::*;
 use smol::{
     channel::{Receiver, Sender},
     io::{BufReader, BufWriter},
+    // prelude::*,
     process::{Child, ChildStderr, Command, Stdio},
     Executor,
 };
 
+pub mod util {
+    use super::*;
+
+    pub fn lsp_pos_to_pos(doc: &helix_core::RopeSlice, pos: lsp::Position) -> usize {
+        let line = doc.line_to_char(pos.line as usize);
+        let line_start = doc.char_to_utf16_cu(line);
+        doc.utf16_cu_to_char(pos.character as usize + line_start)
+    }
+}
+
 /// A type representing all possible values sent from the server to the client.
 #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
 #[serde(deny_unknown_fields)]
@@ -58,7 +70,7 @@ impl Notification {
 }
 
 pub struct Client {
-    process: Child,
+    _process: Child,
     stderr: BufReader<ChildStderr>,
 
     outgoing: Sender<Payload>,
@@ -90,7 +102,7 @@ impl Client {
         let (incoming, outgoing) = Transport::start(ex, reader, writer);
 
         Client {
-            process,
+            _process: process,
             stderr,
 
             outgoing,
@@ -224,15 +236,12 @@ impl Client {
     // Text document
     // -------------------------------------------------------------------------------------------
 
-    pub async fn text_document_did_open(
-        &mut self,
-        state: &helix_core::State,
-    ) -> anyhow::Result<()> {
+    pub async fn text_document_did_open(&mut self, state: &State) -> anyhow::Result<()> {
         self.notify::<lsp::notification::DidOpenTextDocument>(lsp::DidOpenTextDocumentParams {
             text_document: lsp::TextDocumentItem {
                 uri: lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
                 language_id: "rust".to_string(), // TODO: hardcoded for now
-                version: 0,
+                version: state.version,
                 text: String::from(&state.doc),
             },
         })
@@ -242,14 +251,15 @@ impl Client {
     // TODO: trigger any time history.commit_revision happens
     pub async fn text_document_did_change(
         &mut self,
-        state: &helix_core::State,
+        state: &State,
+        transaction: &Transaction,
     ) -> anyhow::Result<()> {
         self.notify::<lsp::notification::DidChangeTextDocument>(lsp::DidChangeTextDocumentParams {
             text_document: lsp::VersionedTextDocumentIdentifier::new(
                 lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
-                0, // TODO: version
+                state.version,
             ),
-            content_changes: vec![], // TODO:
+            content_changes: vec![], // TODO: probably need old_state here too?
         })
         .await
     }
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index 5551e26f..a1a6b9ea 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -568,23 +568,12 @@ impl<'a> Application<'a> {
         use helix_lsp::Notification;
         match notification {
             Some(Notification::PublishDiagnostics(params)) => {
-                let view = self.editor.views.iter_mut().find(|view| {
-                    let path = view
-                        .state
-                        .path
-                        .as_ref()
-                        .map(|path| helix_lsp::Url::from_file_path(path).unwrap());
-
-                    eprintln!("{:?} {} {}", path, params.uri, params.diagnostics.len());
-                    // HAXX
-                    path == Some(params.uri.clone())
-                });
-
-                fn lsp_pos_to_pos(doc: &helix_core::RopeSlice, pos: helix_lsp::Position) -> usize {
-                    let line = doc.line_to_char(pos.line as usize);
-                    let line_start = doc.char_to_utf16_cu(line);
-                    doc.utf16_cu_to_char(pos.character as usize + line_start)
-                }
+                let path = Some(params.uri.to_file_path().unwrap());
+                let view = self
+                    .editor
+                    .views
+                    .iter_mut()
+                    .find(|view| view.state.path == path);
 
                 if let Some(view) = view {
                     let doc = view.state.doc().slice(..);
@@ -592,18 +581,10 @@ impl<'a> Application<'a> {
                         .diagnostics
                         .into_iter()
                         .map(|diagnostic| {
+                            use helix_lsp::util::lsp_pos_to_pos;
                             let start = lsp_pos_to_pos(&doc, diagnostic.range.start);
                             let end = lsp_pos_to_pos(&doc, diagnostic.range.end);
 
-                            // eprintln!(
-                            //     "{:?}-{:?} {}-{} {}",
-                            //     diagnostic.range.start,
-                            //     diagnostic.range.end,
-                            //     start,
-                            //     end,
-                            //     diagnostic.message
-                            // );
-
                             helix_core::Diagnostic {
                                 range: (start, end),
                                 line: diagnostic.range.start.line as usize,
diff --git a/helix-view/src/commands.rs b/helix-view/src/commands.rs
index 1d7737f0..e29d070e 100644
--- a/helix-view/src/commands.rs
+++ b/helix-view/src/commands.rs
@@ -391,6 +391,12 @@ fn append_changes_to_history(view: &mut View) {
     // annotations either add a new layer or compose into the previous one.
     let transaction = Transaction::from(changes).with_selection(view.state.selection().clone());
 
+    // increment document version
+    // TODO: needs to happen on undo/redo too
+    view.state.version += 1;
+
+    // TODO: trigger lsp/documentDidChange with changes
+
     // HAXX: we need to reconstruct the state as it was before the changes..
     let (doc, selection) = view.state.old_state.take().unwrap();
     let mut old_state = State::new(doc);
@@ -399,7 +405,6 @@ fn append_changes_to_history(view: &mut View) {
     // TODO: take transaction by value?
     view.history.commit_revision(&transaction, &old_state);
 
-    // TODO: need to start the state with these vals
     // HAXX
     view.state.old_state = Some((view.state.doc().clone(), view.state.selection.clone()));
 }

From 81ccca0c6a18de86223b8142b5742e0603b9b230 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Wed, 21 Oct 2020 16:42:45 +0900
Subject: [PATCH 09/23] Improve error typing.

---
 Cargo.lock                 |  41 +++++--
 helix-lsp/Cargo.toml       |   1 +
 helix-lsp/src/client.rs    | 242 +++++++++++++++++++++++++++++++++++++
 helix-lsp/src/lib.rs       | 239 +++---------------------------------
 helix-lsp/src/transport.rs |  25 ++--
 5 files changed, 307 insertions(+), 241 deletions(-)
 create mode 100644 helix-lsp/src/client.rs

diff --git a/Cargo.lock b/Cargo.lock
index 2e329fd1..1d7857d5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -100,9 +100,9 @@ dependencies = [
 
 [[package]]
 name = "async-net"
-version = "1.4.7"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee4c3668eb091d781e97f0026b5289b457c77d407a85749a9bb4c057456c428f"
+checksum = "06de475c85affe184648202401d7622afb32f0f74e02192857d0201a16defbe5"
 dependencies = [
  "async-io",
  "blocking",
@@ -350,9 +350,9 @@ checksum = "5fc94b64bb39543b4e432f1790b6bf18e3ee3b74653c5449f63310e9a74b123c"
 
 [[package]]
 name = "futures-lite"
-version = "1.11.1"
+version = "1.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "381a7ad57b1bad34693f63f6f377e1abded7a9c85c9d3eb6771e11c60aaadab9"
+checksum = "5e6c079abfac3ab269e2927ec048dabc89d009ebfdda6b8ee86624f30c689658"
 dependencies = [
  "fastrand",
  "futures-core",
@@ -454,6 +454,7 @@ dependencies = [
  "serde_json",
  "shellexpand",
  "smol",
+ "thiserror",
  "url",
 ]
 
@@ -623,9 +624,9 @@ checksum = "3728d817d99e5ac407411fa471ff9800a778d88a24685968b36824eaf4bee400"
 
 [[package]]
 name = "mio"
-version = "0.7.3"
+version = "0.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e53a6ea5f38c0a48ca42159868c6d8e1bd56c0451238856cc08d58563643bdc3"
+checksum = "f8f1c83949125de4a582aa2da15ae6324d91cf6a58a70ea407643941ff98f558"
 dependencies = [
  "libc",
  "log",
@@ -757,9 +758,9 @@ dependencies = [
 
 [[package]]
 name = "pin-project-lite"
-version = "0.1.10"
+version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e555d9e657502182ac97b539fb3dae8b79cda19e3e4f8ffb5e8de4f18df93c95"
+checksum = "c917123afa01924fc84bb20c4c03f004d9c38e5127e3c039bbf7f4b9c76a2f6b"
 
 [[package]]
 name = "pin-utils"
@@ -1022,6 +1023,26 @@ dependencies = [
  "unicode-width",
 ]
 
+[[package]]
+name = "thiserror"
+version = "1.0.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "318234ffa22e0920fe9a40d7b8369b5f649d490980cf7aadcf1eb91594869b42"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cae2447b6282786c3493999f40a9be2a6ad20cb8bd268b0a0dbf5a065535c0ab"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "thread_local"
 version = "1.0.1"
@@ -1139,9 +1160,9 @@ checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
 
 [[package]]
 name = "wepoll-sys"
-version = "3.0.0"
+version = "3.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "142bc2cba3fe88be1a8fcb55c727fa4cd5b0cf2d7438722792e22f26f04bc1e0"
+checksum = "0fcb14dea929042224824779fbc82d9fab8d2e6d3cbc0ac404de8edf489e77ff"
 dependencies = [
  "cc",
 ]
diff --git a/helix-lsp/Cargo.toml b/helix-lsp/Cargo.toml
index b34c139f..e4956f0b 100644
--- a/helix-lsp/Cargo.toml
+++ b/helix-lsp/Cargo.toml
@@ -20,3 +20,4 @@ serde_json = "1.0"
 serde = { version = "1.0", features = ["derive"] }
 jsonrpc-core = "15.1"
 futures-util = "0.3"
+thiserror = "1.0.21"
diff --git a/helix-lsp/src/client.rs b/helix-lsp/src/client.rs
new file mode 100644
index 00000000..93e137cb
--- /dev/null
+++ b/helix-lsp/src/client.rs
@@ -0,0 +1,242 @@
+use crate::{
+    transport::{Payload, Transport},
+    Error, Notification,
+};
+
+type Result<T> = core::result::Result<T, Error>;
+
+use helix_core::{State, Transaction};
+
+// use std::collections::HashMap;
+
+use jsonrpc_core as jsonrpc;
+use lsp_types as lsp;
+use serde_json::Value;
+
+use smol::{
+    channel::{Receiver, Sender},
+    io::{BufReader, BufWriter},
+    // prelude::*,
+    process::{Child, ChildStderr, Command, Stdio},
+    Executor,
+};
+
+pub struct Client {
+    _process: Child,
+    stderr: BufReader<ChildStderr>,
+
+    outgoing: Sender<Payload>,
+    pub incoming: Receiver<Notification>,
+
+    pub request_counter: u64,
+
+    capabilities: Option<lsp::ServerCapabilities>,
+    // TODO: handle PublishDiagnostics Version
+    // diagnostics: HashMap<lsp::Url, Vec<lsp::Diagnostic>>,
+}
+
+impl Client {
+    pub fn start(ex: &Executor, cmd: &str, args: &[String]) -> Self {
+        let mut process = Command::new(cmd)
+            .args(args)
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped())
+            .spawn()
+            .expect("Failed to start language server");
+        // smol makes sure the process is reaped on drop, but using kill_on_drop(true) maybe?
+
+        // TODO: do we need bufreader/writer here? or do we use async wrappers on unblock?
+        let writer = BufWriter::new(process.stdin.take().expect("Failed to open stdin"));
+        let reader = BufReader::new(process.stdout.take().expect("Failed to open stdout"));
+        let stderr = BufReader::new(process.stderr.take().expect("Failed to open stderr"));
+
+        let (incoming, outgoing) = Transport::start(ex, reader, writer);
+
+        Client {
+            _process: process,
+            stderr,
+
+            outgoing,
+            incoming,
+
+            request_counter: 0,
+
+            capabilities: None,
+            // diagnostics: HashMap::new(),
+        }
+    }
+
+    fn next_request_id(&mut self) -> jsonrpc::Id {
+        let id = jsonrpc::Id::Num(self.request_counter);
+        self.request_counter += 1;
+        id
+    }
+
+    fn to_params(value: Value) -> Result<jsonrpc::Params> {
+        use jsonrpc::Params;
+
+        let params = match value {
+            Value::Null => Params::None,
+            Value::Bool(_) | Value::Number(_) | Value::String(_) => Params::Array(vec![value]),
+            Value::Array(vec) => Params::Array(vec),
+            Value::Object(map) => Params::Map(map),
+        };
+
+        Ok(params)
+    }
+
+    pub async fn request<R: lsp::request::Request>(
+        &mut self,
+        params: R::Params,
+    ) -> Result<R::Result>
+    where
+        R::Params: serde::Serialize,
+        R::Result: core::fmt::Debug, // TODO: temporary
+    {
+        let params = serde_json::to_value(params)?;
+
+        let request = jsonrpc::MethodCall {
+            jsonrpc: Some(jsonrpc::Version::V2),
+            id: self.next_request_id(),
+            method: R::METHOD.to_string(),
+            params: Self::to_params(params)?,
+        };
+
+        let (tx, rx) = smol::channel::bounded::<Result<Value>>(1);
+
+        self.outgoing
+            .send(Payload::Request {
+                chan: tx,
+                value: request,
+            })
+            .await
+            .map_err(|e| Error::Other(e.into()))?;
+
+        let response = rx.recv().await.map_err(|e| Error::Other(e.into()))??;
+
+        let response = serde_json::from_value(response)?;
+
+        // TODO: we should pass request to a sender thread via a channel
+        // so it can't be interleaved
+
+        // TODO: responses can be out of order, we need to register a single shot response channel
+
+        Ok(response)
+    }
+
+    pub async fn notify<R: lsp::notification::Notification>(
+        &mut self,
+        params: R::Params,
+    ) -> Result<()>
+    where
+        R::Params: serde::Serialize,
+    {
+        let params = serde_json::to_value(params)?;
+
+        let notification = jsonrpc::Notification {
+            jsonrpc: Some(jsonrpc::Version::V2),
+            method: R::METHOD.to_string(),
+            params: Self::to_params(params)?,
+        };
+
+        self.outgoing
+            .send(Payload::Notification(notification))
+            .await
+            .map_err(|e| Error::Other(e.into()))?;
+
+        Ok(())
+    }
+
+    // -------------------------------------------------------------------------------------------
+    // General messages
+    // -------------------------------------------------------------------------------------------
+
+    pub async fn initialize(&mut self) -> Result<()> {
+        // TODO: delay any requests that are triggered prior to initialize
+
+        #[allow(deprecated)]
+        let params = lsp::InitializeParams {
+            process_id: Some(u64::from(std::process::id())),
+            root_path: None,
+            // root_uri: Some(lsp_types::Url::parse("file://localhost/")?),
+            root_uri: None, // set to project root in the future
+            initialization_options: None,
+            capabilities: lsp::ClientCapabilities::default(),
+            trace: None,
+            workspace_folders: None,
+            client_info: None,
+        };
+
+        let response = self.request::<lsp::request::Initialize>(params).await?;
+        self.capabilities = Some(response.capabilities);
+
+        // next up, notify<initialized>
+        self.notify::<lsp::notification::Initialized>(lsp::InitializedParams {})
+            .await?;
+
+        Ok(())
+    }
+
+    pub async fn shutdown(&mut self) -> Result<()> {
+        self.request::<lsp::request::Shutdown>(()).await
+    }
+
+    pub async fn exit(&mut self) -> Result<()> {
+        self.notify::<lsp::notification::Exit>(()).await
+    }
+
+    // -------------------------------------------------------------------------------------------
+    // Text document
+    // -------------------------------------------------------------------------------------------
+
+    pub async fn text_document_did_open(&mut self, state: &State) -> Result<()> {
+        self.notify::<lsp::notification::DidOpenTextDocument>(lsp::DidOpenTextDocumentParams {
+            text_document: lsp::TextDocumentItem {
+                uri: lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
+                language_id: "rust".to_string(), // TODO: hardcoded for now
+                version: state.version,
+                text: String::from(&state.doc),
+            },
+        })
+        .await
+    }
+
+    // TODO: trigger any time history.commit_revision happens
+    pub async fn text_document_did_change(
+        &mut self,
+        state: &State,
+        transaction: &Transaction,
+    ) -> Result<()> {
+        self.notify::<lsp::notification::DidChangeTextDocument>(lsp::DidChangeTextDocumentParams {
+            text_document: lsp::VersionedTextDocumentIdentifier::new(
+                lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
+                state.version,
+            ),
+            content_changes: vec![lsp::TextDocumentContentChangeEvent {
+                // range = None -> whole document
+                range: None,        //Some(Range)
+                range_length: None, // u64 apparently deprecated
+                text: "".to_string(),
+            }], // TODO: probably need old_state here too?
+        })
+        .await
+    }
+
+    // TODO: impl into() TextDocumentIdentifier / VersionedTextDocumentIdentifier for State.
+
+    pub async fn text_document_did_close(&mut self, state: &State) -> Result<()> {
+        self.notify::<lsp::notification::DidCloseTextDocument>(lsp::DidCloseTextDocumentParams {
+            text_document: lsp::TextDocumentIdentifier::new(
+                lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
+            ),
+        })
+        .await
+    }
+
+    // will_save / will_save_wait_until
+
+    pub async fn text_document_did_save(&mut self) -> anyhow::Result<()> {
+        unimplemented!()
+    }
+}
diff --git a/helix-lsp/src/lib.rs b/helix-lsp/src/lib.rs
index f8c73902..c37222f1 100644
--- a/helix-lsp/src/lib.rs
+++ b/helix-lsp/src/lib.rs
@@ -1,27 +1,26 @@
+mod client;
 mod transport;
 
-use transport::{Payload, Transport};
-
-use helix_core::{State, Transaction};
-
-// use std::collections::HashMap;
-
 use jsonrpc_core as jsonrpc;
 use lsp_types as lsp;
-use serde_json::Value;
+
+pub use client::Client;
+pub use lsp::{Position, Url};
 
 use serde::{Deserialize, Serialize};
+use thiserror::Error;
 
-pub use lsp::Position;
-pub use lsp::Url;
-
-use smol::{
-    channel::{Receiver, Sender},
-    io::{BufReader, BufWriter},
-    // prelude::*,
-    process::{Child, ChildStderr, Command, Stdio},
-    Executor,
-};
+#[derive(Error, Debug)]
+pub enum Error {
+    #[error("protocol error: {0}")]
+    Rpc(#[from] jsonrpc::Error),
+    #[error("failed to parse: {0}")]
+    Parse(#[from] serde_json::Error),
+    #[error("request timed out")]
+    Timeout,
+    #[error(transparent)]
+    Other(#[from] anyhow::Error),
+}
 
 pub mod util {
     use super::*;
@@ -68,209 +67,3 @@ impl Notification {
         }
     }
 }
-
-pub struct Client {
-    _process: Child,
-    stderr: BufReader<ChildStderr>,
-
-    outgoing: Sender<Payload>,
-    pub incoming: Receiver<Notification>,
-
-    pub request_counter: u64,
-
-    capabilities: Option<lsp::ServerCapabilities>,
-    // TODO: handle PublishDiagnostics Version
-    // diagnostics: HashMap<lsp::Url, Vec<lsp::Diagnostic>>,
-}
-
-impl Client {
-    pub fn start(ex: &Executor, cmd: &str, args: &[String]) -> Self {
-        let mut process = Command::new(cmd)
-            .args(args)
-            .stdin(Stdio::piped())
-            .stdout(Stdio::piped())
-            .stderr(Stdio::piped())
-            .spawn()
-            .expect("Failed to start language server");
-        // smol makes sure the process is reaped on drop, but using kill_on_drop(true) maybe?
-
-        // TODO: do we need bufreader/writer here? or do we use async wrappers on unblock?
-        let writer = BufWriter::new(process.stdin.take().expect("Failed to open stdin"));
-        let reader = BufReader::new(process.stdout.take().expect("Failed to open stdout"));
-        let stderr = BufReader::new(process.stderr.take().expect("Failed to open stderr"));
-
-        let (incoming, outgoing) = Transport::start(ex, reader, writer);
-
-        Client {
-            _process: process,
-            stderr,
-
-            outgoing,
-            incoming,
-
-            request_counter: 0,
-
-            capabilities: None,
-            // diagnostics: HashMap::new(),
-        }
-    }
-
-    fn next_request_id(&mut self) -> jsonrpc::Id {
-        let id = jsonrpc::Id::Num(self.request_counter);
-        self.request_counter += 1;
-        id
-    }
-
-    fn to_params(value: Value) -> anyhow::Result<jsonrpc::Params> {
-        use jsonrpc::Params;
-
-        let params = match value {
-            Value::Null => Params::None,
-            Value::Bool(_) | Value::Number(_) | Value::String(_) => Params::Array(vec![value]),
-            Value::Array(vec) => Params::Array(vec),
-            Value::Object(map) => Params::Map(map),
-        };
-
-        Ok(params)
-    }
-
-    pub async fn request<R: lsp::request::Request>(
-        &mut self,
-        params: R::Params,
-    ) -> anyhow::Result<R::Result>
-    where
-        R::Params: serde::Serialize,
-        R::Result: core::fmt::Debug, // TODO: temporary
-    {
-        let params = serde_json::to_value(params)?;
-
-        let request = jsonrpc::MethodCall {
-            jsonrpc: Some(jsonrpc::Version::V2),
-            id: self.next_request_id(),
-            method: R::METHOD.to_string(),
-            params: Self::to_params(params)?,
-        };
-
-        let (tx, rx) = smol::channel::bounded::<anyhow::Result<Value>>(1);
-
-        self.outgoing
-            .send(Payload::Request {
-                chan: tx,
-                value: request,
-            })
-            .await?;
-
-        let response = rx.recv().await??;
-
-        let response = serde_json::from_value(response)?;
-
-        // TODO: we should pass request to a sender thread via a channel
-        // so it can't be interleaved
-
-        // TODO: responses can be out of order, we need to register a single shot response channel
-
-        Ok(response)
-    }
-
-    pub async fn notify<R: lsp::notification::Notification>(
-        &mut self,
-        params: R::Params,
-    ) -> anyhow::Result<()>
-    where
-        R::Params: serde::Serialize,
-    {
-        let params = serde_json::to_value(params)?;
-
-        let notification = jsonrpc::Notification {
-            jsonrpc: Some(jsonrpc::Version::V2),
-            method: R::METHOD.to_string(),
-            params: Self::to_params(params)?,
-        };
-
-        self.outgoing
-            .send(Payload::Notification(notification))
-            .await?;
-
-        Ok(())
-    }
-
-    // -------------------------------------------------------------------------------------------
-    // General messages
-    // -------------------------------------------------------------------------------------------
-
-    pub async fn initialize(&mut self) -> anyhow::Result<()> {
-        // TODO: delay any requests that are triggered prior to initialize
-
-        #[allow(deprecated)]
-        let params = lsp::InitializeParams {
-            process_id: Some(u64::from(std::process::id())),
-            root_path: None,
-            // root_uri: Some(lsp_types::Url::parse("file://localhost/")?),
-            root_uri: None, // set to project root in the future
-            initialization_options: None,
-            capabilities: lsp::ClientCapabilities::default(),
-            trace: None,
-            workspace_folders: None,
-            client_info: None,
-        };
-
-        let response = self.request::<lsp::request::Initialize>(params).await?;
-        self.capabilities = Some(response.capabilities);
-
-        // next up, notify<initialized>
-        self.notify::<lsp::notification::Initialized>(lsp::InitializedParams {})
-            .await?;
-
-        Ok(())
-    }
-
-    pub async fn shutdown(&mut self) -> anyhow::Result<()> {
-        self.request::<lsp::request::Shutdown>(()).await
-    }
-
-    pub async fn exit(&mut self) -> anyhow::Result<()> {
-        self.notify::<lsp::notification::Exit>(()).await
-    }
-
-    // -------------------------------------------------------------------------------------------
-    // Text document
-    // -------------------------------------------------------------------------------------------
-
-    pub async fn text_document_did_open(&mut self, state: &State) -> anyhow::Result<()> {
-        self.notify::<lsp::notification::DidOpenTextDocument>(lsp::DidOpenTextDocumentParams {
-            text_document: lsp::TextDocumentItem {
-                uri: lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
-                language_id: "rust".to_string(), // TODO: hardcoded for now
-                version: state.version,
-                text: String::from(&state.doc),
-            },
-        })
-        .await
-    }
-
-    // TODO: trigger any time history.commit_revision happens
-    pub async fn text_document_did_change(
-        &mut self,
-        state: &State,
-        transaction: &Transaction,
-    ) -> anyhow::Result<()> {
-        self.notify::<lsp::notification::DidChangeTextDocument>(lsp::DidChangeTextDocumentParams {
-            text_document: lsp::VersionedTextDocumentIdentifier::new(
-                lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
-                state.version,
-            ),
-            content_changes: vec![], // TODO: probably need old_state here too?
-        })
-        .await
-    }
-
-    pub async fn text_document_did_close(&mut self) -> anyhow::Result<()> {
-        unimplemented!()
-    }
-
-    // will_save / will_save_wait_until
-
-    pub async fn text_document_did_save(&mut self) -> anyhow::Result<()> {
-        unimplemented!()
-    }
-}
diff --git a/helix-lsp/src/transport.rs b/helix-lsp/src/transport.rs
index 8915a925..38c3bb57 100644
--- a/helix-lsp/src/transport.rs
+++ b/helix-lsp/src/transport.rs
@@ -1,9 +1,10 @@
 use std::collections::HashMap;
 
-use crate::{Message, Notification};
+use crate::{Error, Message, Notification};
+
+type Result<T> = core::result::Result<T, Error>;
 
 use jsonrpc_core as jsonrpc;
-use lsp_types as lsp;
 use serde_json::Value;
 
 use smol::prelude::*;
@@ -17,7 +18,7 @@ use smol::{
 
 pub(crate) enum Payload {
     Request {
-        chan: Sender<anyhow::Result<Value>>,
+        chan: Sender<Result<Value>>,
         value: jsonrpc::MethodCall,
     },
     Notification(jsonrpc::Notification),
@@ -27,7 +28,7 @@ pub(crate) struct Transport {
     incoming: Sender<Notification>, // TODO Notification | Call
     outgoing: Receiver<Payload>,
 
-    pending_requests: HashMap<jsonrpc::Id, Sender<anyhow::Result<Value>>>,
+    pending_requests: HashMap<jsonrpc::Id, Sender<Result<Value>>>,
     headers: HashMap<String, String>,
 
     writer: BufWriter<ChildStdin>,
@@ -60,7 +61,7 @@ impl Transport {
     async fn recv(
         reader: &mut (impl AsyncBufRead + Unpin),
         headers: &mut HashMap<String, String>,
-    ) -> Result<Message, std::io::Error> {
+    ) -> core::result::Result<Message, std::io::Error> {
         // read headers
         loop {
             let mut header = String::new();
@@ -74,8 +75,10 @@ impl Transport {
 
             let parts: Vec<&str> = header.split(": ").collect();
             if parts.len() != 2 {
-                // return Err(Error::new(ErrorKind::Other, "Failed to parse header"));
-                panic!()
+                return Err(std::io::Error::new(
+                    std::io::ErrorKind::Other,
+                    "Failed to parse header",
+                ));
             }
             headers.insert(parts[0].to_string(), parts[1].to_string());
         }
@@ -155,7 +158,13 @@ impl Transport {
                     .expect("pending_request with id not found!");
                 tx.send(Ok(result)).await?;
             }
-            jsonrpc::Output::Failure(_) => panic!("recv fail"),
+            jsonrpc::Output::Failure(jsonrpc::Failure { id, error, .. }) => {
+                let tx = self
+                    .pending_requests
+                    .remove(&id)
+                    .expect("pending_request with id not found!");
+                tx.send(Err(error.into())).await?;
+            }
             msg => unimplemented!("{:?}", msg),
         }
         Ok(())

From b39849dde1b1277d14dbc4e2e1604e5d020db43d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Thu, 22 Oct 2020 14:35:07 +0900
Subject: [PATCH 10/23] Refactor: Document type as a wrapper around barebones
 State.

---
 Cargo.lock                    |   2 +
 helix-core/src/indent.rs      |  27 ++--
 helix-core/src/state.rs       |  81 -----------
 helix-core/src/syntax.rs      |   2 +-
 helix-core/src/transaction.rs |  36 +----
 helix-lsp/Cargo.toml          |   1 +
 helix-lsp/src/client.rs       |  21 +--
 helix-term/src/application.rs |  48 ++++---
 helix-view/Cargo.toml         |   1 +
 helix-view/src/commands.rs    | 255 ++++++++++++++++++----------------
 helix-view/src/document.rs    | 157 +++++++++++++++++++++
 helix-view/src/editor.rs      |   7 +-
 helix-view/src/keymap.rs      |   9 +-
 helix-view/src/lib.rs         |   2 +
 helix-view/src/view.rs        |  40 ++++--
 15 files changed, 395 insertions(+), 294 deletions(-)
 create mode 100644 helix-view/src/document.rs

diff --git a/Cargo.lock b/Cargo.lock
index 1d7857d5..29a86a36 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -447,6 +447,7 @@ dependencies = [
  "futures-util",
  "glob",
  "helix-core",
+ "helix-view",
  "jsonrpc-core",
  "lsp-types",
  "pathdiff",
@@ -491,6 +492,7 @@ dependencies = [
  "helix-core",
  "once_cell",
  "tui",
+ "url",
 ]
 
 [[package]]
diff --git a/helix-core/src/indent.rs b/helix-core/src/indent.rs
index 2e1a095e..6b9a1ab1 100644
--- a/helix-core/src/indent.rs
+++ b/helix-core/src/indent.rs
@@ -111,17 +111,17 @@ fn find_first_non_whitespace_char(state: &State, line_num: usize) -> usize {
     start
 }
 
-fn suggested_indent_for_line(state: &State, line_num: usize) -> usize {
+fn suggested_indent_for_line(syntax: Option<&Syntax>, state: &State, line_num: usize) -> usize {
     let line = state.doc.line(line_num);
     let current = indent_level_for_line(line);
 
     let start = find_first_non_whitespace_char(state, line_num);
 
-    suggested_indent_for_pos(state, start)
+    suggested_indent_for_pos(syntax, state, start)
 }
 
-pub fn suggested_indent_for_pos(state: &State, pos: usize) -> usize {
-    if let Some(syntax) = &state.syntax {
+pub fn suggested_indent_for_pos(syntax: Option<&Syntax>, state: &State, pos: usize) -> usize {
+    if let Some(syntax) = syntax {
         let byte_start = state.doc.char_to_byte(pos);
         let node = get_highest_syntax_node_at_bytepos(syntax, byte_start);
 
@@ -163,13 +163,18 @@ mod test {
 ",
         );
 
-        let mut state = State::new(doc);
-        state.set_language("source.rust", &[]);
+        let state = State::new(doc);
+        // TODO: set_language
+        let language_config = crate::syntax::LOADER
+            .language_config_for_scope("source.rust")
+            .unwrap();
+        let highlight_config = language_config.highlight_config(&[]).unwrap().unwrap();
+        let syntax = Syntax::new(&state.doc, highlight_config.clone());
 
-        assert_eq!(suggested_indent_for_line(&state, 0), 0); // mod
-        assert_eq!(suggested_indent_for_line(&state, 1), 1); // fn
-        assert_eq!(suggested_indent_for_line(&state, 2), 2); // 1 + 1
-        assert_eq!(suggested_indent_for_line(&state, 4), 1); // }
-        assert_eq!(suggested_indent_for_line(&state, 5), 0); // }
+        assert_eq!(suggested_indent_for_line(Some(&syntax), &state, 0), 0); // mod
+        assert_eq!(suggested_indent_for_line(Some(&syntax), &state, 1), 1); // fn
+        assert_eq!(suggested_indent_for_line(Some(&syntax), &state, 2), 2); // 1 + 1
+        assert_eq!(suggested_indent_for_line(Some(&syntax), &state, 4), 1); // }
+        assert_eq!(suggested_indent_for_line(Some(&syntax), &state, 5), 0); // }
     }
 }
diff --git a/helix-core/src/state.rs b/helix-core/src/state.rs
index 75e5cd40..7fd620a5 100644
--- a/helix-core/src/state.rs
+++ b/helix-core/src/state.rs
@@ -3,34 +3,11 @@ use crate::syntax::LOADER;
 use crate::{ChangeSet, Diagnostic, Position, Range, Rope, RopeSlice, Selection, Syntax};
 use anyhow::Error;
 
-use std::path::PathBuf;
-
-#[derive(Copy, Clone, PartialEq, Eq, Hash)]
-pub enum Mode {
-    Normal,
-    Insert,
-    Goto,
-}
-
 /// A state represents the current editor state of a single buffer.
 pub struct State {
     // TODO: fields should be private but we need to refactor commands.rs first
-    /// Path to file on disk.
-    pub path: Option<PathBuf>,
     pub doc: Rope,
     pub selection: Selection,
-    pub mode: Mode,
-
-    pub restore_cursor: bool,
-
-    // TODO: move these to a Document wrapper?
-    pub syntax: Option<Syntax>,
-    /// Pending changes since last history commit.
-    pub changes: ChangeSet,
-    pub old_state: Option<(Rope, Selection)>,
-
-    pub version: i64,
-    pub diagnostics: Vec<Diagnostic>,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq)]
@@ -49,60 +26,12 @@ pub enum Granularity {
 impl State {
     #[must_use]
     pub fn new(doc: Rope) -> Self {
-        let changes = ChangeSet::new(&doc);
-        let old_state = Some((doc.clone(), Selection::single(0, 0)));
-
         Self {
-            path: None,
             doc,
             selection: Selection::single(0, 0),
-            mode: Mode::Normal,
-            restore_cursor: false,
-            syntax: None,
-            changes,
-            old_state,
-            diagnostics: Vec::new(),
-            version: 0,
         }
     }
 
-    // TODO: passing scopes here is awkward
-    pub fn load(path: PathBuf, scopes: &[String]) -> Result<Self, Error> {
-        use std::{env, fs::File, io::BufReader};
-        let _current_dir = env::current_dir()?;
-
-        let doc = Rope::from_reader(BufReader::new(File::open(path.clone())?))?;
-
-        // TODO: create if not found
-
-        let mut state = Self::new(doc);
-
-        if let Some(language_config) = LOADER.language_config_for_file_name(path.as_path()) {
-            let highlight_config = language_config.highlight_config(scopes).unwrap().unwrap();
-            // TODO: config.configure(scopes) is now delayed, is that ok?
-
-            let syntax = Syntax::new(&state.doc, highlight_config.clone());
-
-            state.syntax = Some(syntax);
-        };
-
-        // canonicalize path to absolute value
-        state.path = Some(std::fs::canonicalize(path)?);
-
-        Ok(state)
-    }
-
-    pub fn set_language(&mut self, scope: &str, scopes: &[String]) {
-        if let Some(language_config) = LOADER.language_config_for_scope(scope) {
-            let highlight_config = language_config.highlight_config(scopes).unwrap().unwrap();
-            // TODO: config.configure(scopes) is now delayed, is that ok?
-
-            let syntax = Syntax::new(&self.doc, highlight_config.clone());
-
-            self.syntax = Some(syntax);
-        };
-    }
-
     // TODO: doc/selection accessors
 
     // TODO: be able to take either Rope or RopeSlice
@@ -116,16 +45,6 @@ impl State {
         &self.selection
     }
 
-    #[inline]
-    pub fn mode(&self) -> Mode {
-        self.mode
-    }
-
-    #[inline]
-    pub fn path(&self) -> Option<&PathBuf> {
-        self.path.as_ref()
-    }
-
     // pub fn doc<R>(&self, range: R) -> RopeSlice
     // where
     //     R: std::ops::RangeBounds<usize>,
diff --git a/helix-core/src/syntax.rs b/helix-core/src/syntax.rs
index 02903637..f4826fb4 100644
--- a/helix-core/src/syntax.rs
+++ b/helix-core/src/syntax.rs
@@ -66,7 +66,7 @@ impl LanguageConfiguration {
 
 use once_cell::sync::Lazy;
 
-pub(crate) static LOADER: Lazy<Loader> = Lazy::new(Loader::init);
+pub static LOADER: Lazy<Loader> = Lazy::new(Loader::init);
 
 pub struct Loader {
     // highlight_names ?
diff --git a/helix-core/src/transaction.rs b/helix-core/src/transaction.rs
index 6f3956aa..9bd8c615 100644
--- a/helix-core/src/transaction.rs
+++ b/helix-core/src/transaction.rs
@@ -351,22 +351,6 @@ pub struct Transaction {
     // scroll_into_view
 }
 
-/// Like std::mem::replace() except it allows the replacement value to be mapped from the
-/// original value.
-pub fn take_with<T, F>(mut_ref: &mut T, closure: F)
-where
-    F: FnOnce(T) -> T,
-{
-    use std::{panic, ptr};
-
-    unsafe {
-        let old_t = ptr::read(mut_ref);
-        let new_t = panic::catch_unwind(panic::AssertUnwindSafe(|| closure(old_t)))
-            .unwrap_or_else(|_| ::std::process::abort());
-        ptr::write(mut_ref, new_t);
-    }
-}
-
 impl Transaction {
     /// Create a new, empty transaction.
     pub fn new(state: &mut State) -> Self {
@@ -376,29 +360,21 @@ impl Transaction {
         }
     }
 
+    pub fn changes(&self) -> &ChangeSet {
+        &self.changes
+    }
+
     /// Returns true if applied successfully.
     pub fn apply(&self, state: &mut State) -> bool {
         if !self.changes.is_empty() {
-            // TODO: also avoid mapping the selection if not necessary
-
-            let old_doc = state.doc().clone();
-
             // apply changes to the document
             if !self.changes.apply(&mut state.doc) {
                 return false;
             }
-
-            // Compose this transaction with the previous one
-            take_with(&mut state.changes, |changes| {
-                changes.compose(self.changes.clone()).unwrap()
-            });
-
-            if let Some(syntax) = &mut state.syntax {
-                // TODO: no unwrap
-                syntax.update(&old_doc, &state.doc, &self.changes).unwrap();
-            }
         }
 
+        // TODO: also avoid mapping the selection if not necessary
+
         // update the selection: either take the selection specified in the transaction, or map the
         // current selection through changes.
         state.selection = self
diff --git a/helix-lsp/Cargo.toml b/helix-lsp/Cargo.toml
index e4956f0b..351c3b0e 100644
--- a/helix-lsp/Cargo.toml
+++ b/helix-lsp/Cargo.toml
@@ -8,6 +8,7 @@ edition = "2018"
 
 [dependencies]
 helix-core = { path = "../helix-core" }
+helix-view = { path = "../helix-view" }
 
 lsp-types = { version = "0.82", features = ["proposed"] }
 smol = "1.2"
diff --git a/helix-lsp/src/client.rs b/helix-lsp/src/client.rs
index 93e137cb..56413768 100644
--- a/helix-lsp/src/client.rs
+++ b/helix-lsp/src/client.rs
@@ -6,6 +6,7 @@ use crate::{
 type Result<T> = core::result::Result<T, Error>;
 
 use helix_core::{State, Transaction};
+use helix_view::Document;
 
 // use std::collections::HashMap;
 
@@ -190,13 +191,13 @@ impl Client {
     // Text document
     // -------------------------------------------------------------------------------------------
 
-    pub async fn text_document_did_open(&mut self, state: &State) -> Result<()> {
+    pub async fn text_document_did_open(&mut self, doc: &Document) -> Result<()> {
         self.notify::<lsp::notification::DidOpenTextDocument>(lsp::DidOpenTextDocumentParams {
             text_document: lsp::TextDocumentItem {
-                uri: lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
+                uri: lsp::Url::from_file_path(doc.path().unwrap()).unwrap(),
                 language_id: "rust".to_string(), // TODO: hardcoded for now
-                version: state.version,
-                text: String::from(&state.doc),
+                version: doc.version,
+                text: String::from(doc.text()),
             },
         })
         .await
@@ -205,13 +206,13 @@ impl Client {
     // TODO: trigger any time history.commit_revision happens
     pub async fn text_document_did_change(
         &mut self,
-        state: &State,
+        doc: &Document,
         transaction: &Transaction,
     ) -> Result<()> {
         self.notify::<lsp::notification::DidChangeTextDocument>(lsp::DidChangeTextDocumentParams {
             text_document: lsp::VersionedTextDocumentIdentifier::new(
-                lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
-                state.version,
+                lsp::Url::from_file_path(doc.path().unwrap()).unwrap(),
+                doc.version,
             ),
             content_changes: vec![lsp::TextDocumentContentChangeEvent {
                 // range = None -> whole document
@@ -223,12 +224,12 @@ impl Client {
         .await
     }
 
-    // TODO: impl into() TextDocumentIdentifier / VersionedTextDocumentIdentifier for State.
+    // TODO: impl into() TextDocumentIdentifier / VersionedTextDocumentIdentifier for Document.
 
-    pub async fn text_document_did_close(&mut self, state: &State) -> Result<()> {
+    pub async fn text_document_did_close(&mut self, doc: &Document) -> Result<()> {
         self.notify::<lsp::notification::DidCloseTextDocument>(lsp::DidCloseTextDocumentParams {
             text_document: lsp::TextDocumentIdentifier::new(
-                lsp::Url::from_file_path(state.path().unwrap()).unwrap(),
+                lsp::Url::from_file_path(doc.path().unwrap()).unwrap(),
             ),
         })
         .await
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index a1a6b9ea..b9594b7e 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -1,10 +1,11 @@
 use clap::ArgMatches as Args;
-use helix_core::{indent::TAB_WIDTH, state::Mode, syntax::HighlightEvent, Position, Range, State};
+use helix_core::{indent::TAB_WIDTH, syntax::HighlightEvent, Position, Range, State};
 use helix_view::{
     commands,
+    document::Mode,
     keymap::{self, Keymaps},
     prompt::Prompt,
-    Editor, Theme, View,
+    Document, Editor, Theme, View,
 };
 
 use std::{
@@ -95,15 +96,15 @@ impl Renderer {
         self.surface.set_style(area, theme.get("ui.background"));
 
         // TODO: inefficient, should feed chunks.iter() to tree_sitter.parse_with(|offset, pos|)
-        let source_code = view.state.doc().to_string();
+        let source_code = view.doc.text().to_string();
 
         let last_line = view.last_line();
 
         let range = {
             // calculate viewport byte ranges
-            let start = view.state.doc().line_to_byte(view.first_line);
-            let end = view.state.doc().line_to_byte(last_line)
-                + view.state.doc().line(last_line).len_bytes();
+            let start = view.doc.text().line_to_byte(view.first_line);
+            let end = view.doc.text().line_to_byte(last_line)
+                + view.doc.text().line(last_line).len_bytes();
 
             start..end
         };
@@ -111,7 +112,7 @@ impl Renderer {
         // TODO: range doesn't actually restrict source, just highlight range
         // TODO: cache highlight results
         // TODO: only recalculate when state.doc is actually modified
-        let highlights: Vec<_> = match view.state.syntax.as_mut() {
+        let highlights: Vec<_> = match view.doc.syntax.as_mut() {
             Some(syntax) => {
                 syntax
                     .highlight_iter(source_code.as_bytes(), Some(range), None, |_| None)
@@ -127,6 +128,7 @@ impl Renderer {
         let mut visual_x = 0;
         let mut line = 0u16;
         let visible_selections: Vec<Range> = view
+            .doc
             .state
             .selection()
             .ranges()
@@ -147,10 +149,10 @@ impl Renderer {
                 HighlightEvent::Source { start, end } => {
                     // TODO: filter out spans out of viewport for now..
 
-                    let start = view.state.doc().byte_to_char(start);
-                    let end = view.state.doc().byte_to_char(end); // <-- index 744, len 743
+                    let start = view.doc.text().byte_to_char(start);
+                    let end = view.doc.text().byte_to_char(end); // <-- index 744, len 743
 
-                    let text = view.state.doc().slice(start..end);
+                    let text = view.doc.text().slice(start..end);
 
                     use helix_core::graphemes::{grapheme_width, RopeGraphemes};
 
@@ -207,7 +209,7 @@ impl Renderer {
 
                             // ugh, improve with a traverse method
                             // or interleave highlight spans with selection and diagnostic spans
-                            let style = if view.state.diagnostics.iter().any(|diagnostic| {
+                            let style = if view.doc.diagnostics.iter().any(|diagnostic| {
                                 diagnostic.range.0 <= char_index && diagnostic.range.1 > char_index
                             }) {
                                 style.clone().add_modifier(Modifier::UNDERLINED)
@@ -233,7 +235,7 @@ impl Renderer {
         let warning: Style = theme.get("warning");
         let last_line = view.last_line();
         for (i, line) in (view.first_line..last_line).enumerate() {
-            if view.state.diagnostics.iter().any(|d| d.line == line) {
+            if view.doc.diagnostics.iter().any(|d| d.line == line) {
                 self.surface.set_stringn(0, i as u16, "●", 1, warning);
             }
 
@@ -243,7 +245,7 @@ impl Renderer {
     }
 
     pub fn render_statusline(&mut self, view: &View, theme: &Theme) {
-        let mode = match view.state.mode() {
+        let mode = match view.doc.mode() {
             Mode::Insert => "INS",
             Mode::Normal => "NOR",
             Mode::Goto => "GOTO",
@@ -259,7 +261,7 @@ impl Renderer {
         self.surface.set_string(
             self.size.0 - 10,
             self.size.1 - 2,
-            format!("{}", view.state.diagnostics.len()),
+            format!("{}", view.doc.diagnostics.len()),
             self.text_color,
         );
     }
@@ -329,14 +331,14 @@ impl Renderer {
 
     pub fn render_cursor(&mut self, view: &View, prompt: Option<&Prompt>, viewport: Rect) {
         let mut stdout = stdout();
-        match view.state.mode() {
+        match view.doc.mode() {
             Mode::Insert => write!(stdout, "\x1B[6 q"),
             mode => write!(stdout, "\x1B[2 q"),
         };
         let pos = if let Some(prompt) = prompt {
             Position::new(self.size.0 as usize, 2 + prompt.cursor)
         } else {
-            if let Some(path) = view.state.path() {
+            if let Some(path) = view.doc.path() {
                 self.surface.set_string(
                     6,
                     self.size.1 - 1,
@@ -345,10 +347,10 @@ impl Renderer {
                 );
             }
 
-            let cursor = view.state.selection().cursor();
+            let cursor = view.doc.state.selection().cursor();
 
             let mut pos = view
-                .screen_coords_at_pos(&view.state.doc().slice(..), cursor)
+                .screen_coords_at_pos(&view.doc.text().slice(..), cursor)
                 .expect("Cursor is out of bounds.");
             pos.col += viewport.x as usize;
             pos.row += viewport.y as usize;
@@ -416,7 +418,7 @@ impl<'a> Application<'a> {
         let res = self.lsp.initialize().await;
         let res = self
             .lsp
-            .text_document_did_open(&self.editor.view().unwrap().state)
+            .text_document_did_open(&self.editor.view().unwrap().doc)
             .await;
 
         self.render();
@@ -469,7 +471,7 @@ impl<'a> Application<'a> {
                     let keys = vec![event];
                     // TODO: sequences (`gg`)
                     // TODO: handle count other than 1
-                    match view.state.mode() {
+                    match view.doc.mode() {
                         Mode::Insert => {
                             if let Some(command) = self.keymap[&Mode::Insert].get(&keys) {
                                 command(view, 1);
@@ -573,10 +575,10 @@ impl<'a> Application<'a> {
                     .editor
                     .views
                     .iter_mut()
-                    .find(|view| view.state.path == path);
+                    .find(|view| view.doc.path == path);
 
                 if let Some(view) = view {
-                    let doc = view.state.doc().slice(..);
+                    let doc = view.doc.text().slice(..);
                     let diagnostics = params
                         .diagnostics
                         .into_iter()
@@ -596,7 +598,7 @@ impl<'a> Application<'a> {
                         })
                         .collect();
 
-                    view.state.diagnostics = diagnostics;
+                    view.doc.diagnostics = diagnostics;
 
                     self.render();
                 }
diff --git a/helix-view/Cargo.toml b/helix-view/Cargo.toml
index 330ae696..9d53f929 100644
--- a/helix-view/Cargo.toml
+++ b/helix-view/Cargo.toml
@@ -19,3 +19,4 @@ helix-core = { path = "../helix-core" }
 tui = { git = "https://github.com/fdehau/tui-rs", default-features = false, features = ["crossterm"], optional = true}
 crossterm = { version = "0.18", features = ["event-stream"], optional = true}
 once_cell = "1.4"
+url = "2"
diff --git a/helix-view/src/commands.rs b/helix-view/src/commands.rs
index e29d070e..b5350ff4 100644
--- a/helix-view/src/commands.rs
+++ b/helix-view/src/commands.rs
@@ -3,12 +3,13 @@ use helix_core::{
     indent::TAB_WIDTH,
     regex::Regex,
     register, selection,
-    state::{Direction, Granularity, Mode, State},
+    state::{Direction, Granularity, State},
     ChangeSet, Range, Selection, Tendril, Transaction,
 };
 use once_cell::sync::Lazy;
 
 use crate::{
+    document::Mode,
     prompt::Prompt,
     view::{View, PADDING},
 };
@@ -19,36 +20,40 @@ pub type Command = fn(view: &mut View, count: usize);
 
 pub fn move_char_left(view: &mut View, count: usize) {
     // TODO: use a transaction
-    let selection = view
-        .state
-        .move_selection(Direction::Backward, Granularity::Character, count);
-    view.state.selection = selection;
+    let selection =
+        view.doc
+            .state
+            .move_selection(Direction::Backward, Granularity::Character, count);
+    view.doc.state.selection = selection;
 }
 
 pub fn move_char_right(view: &mut View, count: usize) {
     // TODO: use a transaction
-    view.state.selection =
-        view.state
+    view.doc.state.selection =
+        view.doc
+            .state
             .move_selection(Direction::Forward, Granularity::Character, count);
 }
 
 pub fn move_line_up(view: &mut View, count: usize) {
     // TODO: use a transaction
-    view.state.selection = view
-        .state
-        .move_selection(Direction::Backward, Granularity::Line, count);
+    view.doc.state.selection =
+        view.doc
+            .state
+            .move_selection(Direction::Backward, Granularity::Line, count);
 }
 
 pub fn move_line_down(view: &mut View, count: usize) {
     // TODO: use a transaction
-    view.state.selection = view
-        .state
-        .move_selection(Direction::Forward, Granularity::Line, count);
+    view.doc.state.selection =
+        view.doc
+            .state
+            .move_selection(Direction::Forward, Granularity::Line, count);
 }
 
 pub fn move_line_end(view: &mut View, _count: usize) {
     // TODO: use a transaction
-    let lines = selection_lines(&view.state);
+    let lines = selection_lines(&view.doc.state);
 
     let positions = lines
         .into_iter()
@@ -57,89 +62,89 @@ pub fn move_line_end(view: &mut View, _count: usize) {
 
             // Line end is pos at the start of next line - 1
             // subtract another 1 because the line ends with \n
-            view.state.doc.line_to_char(index + 1).saturating_sub(2)
+            view.doc.text().line_to_char(index + 1).saturating_sub(2)
         })
         .map(|pos| Range::new(pos, pos));
 
     let selection = Selection::new(positions.collect(), 0);
 
-    let transaction = Transaction::new(&mut view.state).with_selection(selection);
+    let transaction = Transaction::new(&mut view.doc.state).with_selection(selection);
 
-    transaction.apply(&mut view.state);
+    view.doc.apply(&transaction);
 }
 
 pub fn move_line_start(view: &mut View, _count: usize) {
-    let lines = selection_lines(&view.state);
+    let lines = selection_lines(&view.doc.state);
 
     let positions = lines
         .into_iter()
         .map(|index| {
             // adjust all positions to the start of the line.
-            view.state.doc.line_to_char(index)
+            view.doc.text().line_to_char(index)
         })
         .map(|pos| Range::new(pos, pos));
 
     let selection = Selection::new(positions.collect(), 0);
 
-    let transaction = Transaction::new(&mut view.state).with_selection(selection);
+    let transaction = Transaction::new(&mut view.doc.state).with_selection(selection);
 
-    transaction.apply(&mut view.state);
+    view.doc.apply(&transaction);
 }
 
 pub fn move_next_word_start(view: &mut View, count: usize) {
-    let pos = view.state.move_pos(
-        view.state.selection.cursor(),
+    let pos = view.doc.state.move_pos(
+        view.doc.state.selection.cursor(),
         Direction::Forward,
         Granularity::Word,
         count,
     );
 
     // TODO: use a transaction
-    view.state.selection = Selection::single(pos, pos);
+    view.doc.state.selection = Selection::single(pos, pos);
 }
 
 pub fn move_prev_word_start(view: &mut View, count: usize) {
-    let pos = view.state.move_pos(
-        view.state.selection.cursor(),
+    let pos = view.doc.state.move_pos(
+        view.doc.state.selection.cursor(),
         Direction::Backward,
         Granularity::Word,
         count,
     );
 
     // TODO: use a transaction
-    view.state.selection = Selection::single(pos, pos);
+    view.doc.state.selection = Selection::single(pos, pos);
 }
 
 pub fn move_next_word_end(view: &mut View, count: usize) {
     let pos = State::move_next_word_end(
-        &view.state.doc().slice(..),
-        view.state.selection.cursor(),
+        &view.doc.text().slice(..),
+        view.doc.state.selection.cursor(),
         count,
     );
 
     // TODO: use a transaction
-    view.state.selection = Selection::single(pos, pos);
+    view.doc.state.selection = Selection::single(pos, pos);
 }
 
 pub fn move_file_start(view: &mut View, _count: usize) {
     // TODO: use a transaction
-    view.state.selection = Selection::single(0, 0);
+    view.doc.state.selection = Selection::single(0, 0);
 
-    view.state.mode = Mode::Normal;
+    view.doc.mode = Mode::Normal;
 }
 
 pub fn move_file_end(view: &mut View, _count: usize) {
     // TODO: use a transaction
-    let text = &view.state.doc;
+    let text = &view.doc.text();
     let last_line = text.line_to_char(text.len_lines().saturating_sub(2));
-    view.state.selection = Selection::single(last_line, last_line);
+    view.doc.state.selection = Selection::single(last_line, last_line);
 
-    view.state.mode = Mode::Normal;
+    view.doc.mode = Mode::Normal;
 }
 
 pub fn check_cursor_in_view(view: &mut View) -> bool {
-    let cursor = view.state.selection().cursor();
-    let line = view.state.doc().char_to_line(cursor);
+    let cursor = view.doc.state.selection().cursor();
+    let line = view.doc.text().char_to_line(cursor);
     let document_end = view.first_line + view.size.1.saturating_sub(1) as usize;
 
     if (line > document_end.saturating_sub(PADDING)) | (line < view.first_line + PADDING) {
@@ -156,19 +161,19 @@ pub fn page_up(view: &mut View, _count: usize) {
     view.first_line = view.first_line.saturating_sub(view.size.1 as usize);
 
     if !check_cursor_in_view(view) {
-        let text = view.state.doc();
+        let text = view.doc.text();
         let pos = text.line_to_char(view.last_line().saturating_sub(PADDING));
-        view.state.selection = Selection::single(pos, pos);
+        view.doc.state.selection = Selection::single(pos, pos);
     }
 }
 
 pub fn page_down(view: &mut View, _count: usize) {
     view.first_line += view.size.1 as usize + PADDING;
 
-    if view.first_line < view.state.doc().len_lines() {
-        let text = view.state.doc();
+    if view.first_line < view.doc.text().len_lines() {
+        let text = view.doc.text();
         let pos = text.line_to_char(view.first_line as usize);
-        view.state.selection = Selection::single(pos, pos);
+        view.doc.state.selection = Selection::single(pos, pos);
     }
 }
 
@@ -180,79 +185,84 @@ pub fn half_page_up(view: &mut View, _count: usize) {
     view.first_line = view.first_line.saturating_sub(view.size.1 as usize / 2);
 
     if !check_cursor_in_view(view) {
-        let text = &view.state.doc;
+        let text = &view.doc.text();
         let pos = text.line_to_char(view.last_line() - PADDING);
-        view.state.selection = Selection::single(pos, pos);
+        view.doc.state.selection = Selection::single(pos, pos);
     }
 }
 
 pub fn half_page_down(view: &mut View, _count: usize) {
-    let lines = view.state.doc().len_lines();
+    let lines = view.doc.text().len_lines();
     if view.first_line < lines.saturating_sub(view.size.1 as usize) {
         view.first_line += view.size.1 as usize / 2;
     }
     if !check_cursor_in_view(view) {
-        let text = view.state.doc();
+        let text = view.doc.text();
         let pos = text.line_to_char(view.first_line as usize);
-        view.state.selection = Selection::single(pos, pos);
+        view.doc.state.selection = Selection::single(pos, pos);
     }
 }
 // avoid select by default by having a visual mode switch that makes movements into selects
 
 pub fn extend_char_left(view: &mut View, count: usize) {
     // TODO: use a transaction
-    let selection = view
-        .state
-        .extend_selection(Direction::Backward, Granularity::Character, count);
-    view.state.selection = selection;
+    let selection =
+        view.doc
+            .state
+            .extend_selection(Direction::Backward, Granularity::Character, count);
+    view.doc.state.selection = selection;
 }
 
 pub fn extend_char_right(view: &mut View, count: usize) {
     // TODO: use a transaction
-    view.state.selection =
-        view.state
+    view.doc.state.selection =
+        view.doc
+            .state
             .extend_selection(Direction::Forward, Granularity::Character, count);
 }
 
 pub fn extend_line_up(view: &mut View, count: usize) {
     // TODO: use a transaction
-    view.state.selection =
-        view.state
+    view.doc.state.selection =
+        view.doc
+            .state
             .extend_selection(Direction::Backward, Granularity::Line, count);
 }
 
 pub fn extend_line_down(view: &mut View, count: usize) {
     // TODO: use a transaction
-    view.state.selection =
-        view.state
+    view.doc.state.selection =
+        view.doc
+            .state
             .extend_selection(Direction::Forward, Granularity::Line, count);
 }
 
 pub fn split_selection_on_newline(view: &mut View, _count: usize) {
-    let text = &view.state.doc.slice(..);
+    let text = &view.doc.text().slice(..);
     // only compile the regex once
     #[allow(clippy::trivial_regex)]
     static REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"\n").unwrap());
     // TODO: use a transaction
-    view.state.selection = selection::split_on_matches(text, view.state.selection(), &REGEX)
+    view.doc.state.selection = selection::split_on_matches(text, view.doc.state.selection(), &REGEX)
 }
 
 pub fn select_line(view: &mut View, _count: usize) {
     // TODO: count
-    let pos = view.state.selection().primary();
-    let text = view.state.doc();
+    let pos = view.doc.state.selection().primary();
+    let text = view.doc.text();
     let line = text.char_to_line(pos.head);
     let start = text.line_to_char(line);
     let end = text.line_to_char(line + 1).saturating_sub(1);
 
     // TODO: use a transaction
-    view.state.selection = Selection::single(start, end);
+    view.doc.state.selection = Selection::single(start, end);
 }
 
 pub fn delete_selection(view: &mut View, _count: usize) {
-    let transaction =
-        Transaction::change_by_selection(&view.state, |range| (range.from(), range.to() + 1, None));
-    transaction.apply(&mut view.state);
+    let transaction = Transaction::change_by_selection(&view.doc.state, |range| {
+        (range.from(), range.to() + 1, None)
+    });
+    view.doc.apply(&transaction);
 
     append_changes_to_history(view);
 }
@@ -263,21 +273,23 @@ pub fn change_selection(view: &mut View, count: usize) {
 }
 
 pub fn collapse_selection(view: &mut View, _count: usize) {
-    view.state.selection = view
+    view.doc.state.selection = view
+        .doc
         .state
         .selection
         .transform(|range| Range::new(range.head, range.head))
 }
 
 pub fn flip_selections(view: &mut View, _count: usize) {
-    view.state.selection = view
+    view.doc.state.selection = view
+        .doc
         .state
         .selection
         .transform(|range| Range::new(range.head, range.anchor))
 }
 
 fn enter_insert_mode(view: &mut View) {
-    view.state.mode = Mode::Insert;
+    view.doc.mode = Mode::Insert;
 
     append_changes_to_history(view);
 }
@@ -285,7 +297,8 @@ fn enter_insert_mode(view: &mut View) {
 pub fn insert_mode(view: &mut View, _count: usize) {
     enter_insert_mode(view);
 
-    view.state.selection = view
+    view.doc.state.selection = view
+        .doc
         .state
         .selection
         .transform(|range| Range::new(range.to(), range.from()))
@@ -294,11 +307,11 @@ pub fn insert_mode(view: &mut View, _count: usize) {
 // inserts at the end of each selection
 pub fn append_mode(view: &mut View, _count: usize) {
     enter_insert_mode(view);
-    view.state.restore_cursor = true;
+    view.doc.restore_cursor = true;
 
     // TODO: as transaction
-    let text = &view.state.doc.slice(..);
-    view.state.selection = view.state.selection.transform(|range| {
+    let text = &view.doc.text().slice(..);
+    view.doc.state.selection = view.doc.state.selection.transform(|range| {
         // TODO: to() + next char
         Range::new(
             range.from(),
@@ -346,13 +359,13 @@ pub fn append_to_line(view: &mut View, count: usize) {
 pub fn open_below(view: &mut View, _count: usize) {
     enter_insert_mode(view);
 
-    let lines = selection_lines(&view.state);
+    let lines = selection_lines(&view.doc.state);
 
     let positions: Vec<_> = lines
         .into_iter()
         .map(|index| {
             // adjust all positions to the end of the line/start of the next one.
-            view.state.doc.line_to_char(index + 1)
+            view.doc.text().line_to_char(index + 1)
         })
         .collect();
 
@@ -373,63 +386,63 @@ pub fn open_below(view: &mut View, _count: usize) {
         0,
     );
 
-    let transaction = Transaction::change(&view.state, changes).with_selection(selection);
+    let transaction = Transaction::change(&view.doc.state, changes).with_selection(selection);
 
-    transaction.apply(&mut view.state);
+    view.doc.apply(&transaction);
 }
 
 // O inserts a new line before each line with a selection
 
 fn append_changes_to_history(view: &mut View) {
-    if view.state.changes.is_empty() {
+    if view.doc.changes.is_empty() {
         return;
     }
 
-    let new_changeset = ChangeSet::new(view.state.doc());
-    let changes = std::mem::replace(&mut view.state.changes, new_changeset);
+    let new_changeset = ChangeSet::new(view.doc.text());
+    let changes = std::mem::replace(&mut view.doc.changes, new_changeset);
     // Instead of doing this messy merge we could always commit, and based on transaction
     // annotations either add a new layer or compose into the previous one.
-    let transaction = Transaction::from(changes).with_selection(view.state.selection().clone());
+    let transaction = Transaction::from(changes).with_selection(view.doc.state.selection().clone());
 
     // increment document version
     // TODO: needs to happen on undo/redo too
-    view.state.version += 1;
+    view.doc.version += 1;
 
     // TODO: trigger lsp/documentDidChange with changes
 
     // HAXX: we need to reconstruct the state as it was before the changes..
-    let (doc, selection) = view.state.old_state.take().unwrap();
+    let (doc, selection) = view.doc.old_state.take().unwrap();
     let mut old_state = State::new(doc);
     old_state.selection = selection;
 
     // TODO: take transaction by value?
-    view.history.commit_revision(&transaction, &old_state);
+    view.doc.history.commit_revision(&transaction, &old_state);
 
     // HAXX
-    view.state.old_state = Some((view.state.doc().clone(), view.state.selection.clone()));
+    view.doc.old_state = Some((view.doc.text().clone(), view.doc.state.selection.clone()));
 }
 
 pub fn normal_mode(view: &mut View, _count: usize) {
-    view.state.mode = Mode::Normal;
+    view.doc.mode = Mode::Normal;
 
     append_changes_to_history(view);
 
     // if leaving append mode, move cursor back by 1
-    if view.state.restore_cursor {
-        let text = &view.state.doc.slice(..);
-        view.state.selection = view.state.selection.transform(|range| {
+    if view.doc.restore_cursor {
+        let text = &view.doc.text().slice(..);
+        view.doc.state.selection = view.doc.state.selection.transform(|range| {
             Range::new(
                 range.from(),
                 graphemes::prev_grapheme_boundary(text, range.to()),
             )
         });
 
-        view.state.restore_cursor = false;
+        view.doc.restore_cursor = false;
     }
 }
 
 pub fn goto_mode(view: &mut View, _count: usize) {
-    view.state.mode = Mode::Goto;
+    view.doc.mode = Mode::Goto;
 }
 
 // NOTE: Transactions in this module get appended to history when we switch back to normal mode.
@@ -438,9 +451,9 @@ pub mod insert {
     // TODO: insert means add text just before cursor, on exit we should be on the last letter.
     pub fn insert_char(view: &mut View, c: char) {
         let c = Tendril::from_char(c);
-        let transaction = Transaction::insert(&view.state, c);
+        let transaction = Transaction::insert(&view.doc.state, c);
 
-        transaction.apply(&mut view.state);
+        view.doc.apply(&transaction);
     }
 
     pub fn insert_tab(view: &mut View, _count: usize) {
@@ -448,41 +461,44 @@ pub mod insert {
     }
 
     pub fn insert_newline(view: &mut View, _count: usize) {
-        let transaction = Transaction::change_by_selection(&view.state, |range| {
-            let indent_level =
-                helix_core::indent::suggested_indent_for_pos(&view.state, range.head);
+        let transaction = Transaction::change_by_selection(&view.doc.state, |range| {
+            let indent_level = helix_core::indent::suggested_indent_for_pos(
+                view.doc.syntax.as_ref(),
+                &view.doc.state,
+                range.head,
+            );
             let indent = " ".repeat(TAB_WIDTH).repeat(indent_level);
             let mut text = String::with_capacity(1 + indent.len());
             text.push('\n');
             text.push_str(&indent);
             (range.head, range.head, Some(text.into()))
         });
-        transaction.apply(&mut view.state);
+        view.doc.apply(&transaction);
     }
 
     // TODO: handle indent-aware delete
     pub fn delete_char_backward(view: &mut View, count: usize) {
-        let text = &view.state.doc.slice(..);
-        let transaction = Transaction::change_by_selection(&view.state, |range| {
+        let text = &view.doc.text().slice(..);
+        let transaction = Transaction::change_by_selection(&view.doc.state, |range| {
             (
                 graphemes::nth_prev_grapheme_boundary(text, range.head, count),
                 range.head,
                 None,
             )
         });
-        transaction.apply(&mut view.state);
+        view.doc.apply(&transaction);
     }
 
     pub fn delete_char_forward(view: &mut View, count: usize) {
-        let text = &view.state.doc.slice(..);
-        let transaction = Transaction::change_by_selection(&view.state, |range| {
+        let text = &view.doc.text().slice(..);
+        let transaction = Transaction::change_by_selection(&view.doc.state, |range| {
             (
                 range.head,
                 graphemes::nth_next_grapheme_boundary(text, range.head, count),
                 None,
             )
         });
-        transaction.apply(&mut view.state);
+        view.doc.apply(&transaction);
     }
 }
 
@@ -493,13 +509,13 @@ pub fn insert_char_prompt(prompt: &mut Prompt, c: char) {
 // Undo / Redo
 
 pub fn undo(view: &mut View, _count: usize) {
-    view.history.undo(&mut view.state);
+    view.doc.history.undo(&mut view.doc.state);
 
     // TODO: each command could simply return a Option<transaction>, then the higher level handles storing it?
 }
 
 pub fn redo(view: &mut View, _count: usize) {
-    view.history.redo(&mut view.state);
+    view.doc.history.redo(&mut view.doc.state);
 }
 
 // Yank / Paste
@@ -507,9 +523,10 @@ pub fn redo(view: &mut View, _count: usize) {
 pub fn yank(view: &mut View, _count: usize) {
     // TODO: should selections be made end inclusive?
     let values = view
+        .doc
         .state
         .selection()
-        .fragments(&view.state.doc().slice(..))
+        .fragments(&view.doc.text().slice(..))
         .map(|cow| cow.into_owned())
         .collect();
 
@@ -550,18 +567,18 @@ pub fn paste(view: &mut View, _count: usize) {
         let transaction = if linewise {
             // paste on the next line
             // TODO: can simply take a range + modifier and compute the right pos without ifs
-            let text = view.state.doc();
-            Transaction::change_by_selection(&view.state, |range| {
+            let text = view.doc.text();
+            Transaction::change_by_selection(&view.doc.state, |range| {
                 let line_end = text.line_to_char(text.char_to_line(range.head) + 1);
                 (line_end, line_end, Some(values.next().unwrap()))
             })
         } else {
-            Transaction::change_by_selection(&view.state, |range| {
+            Transaction::change_by_selection(&view.doc.state, |range| {
                 (range.head + 1, range.head + 1, Some(values.next().unwrap()))
             })
         };
 
-        transaction.apply(&mut view.state);
+        view.doc.apply(&transaction);
         append_changes_to_history(view);
     }
 }
@@ -570,9 +587,9 @@ fn get_lines(view: &View) -> Vec<usize> {
     let mut lines = Vec::new();
 
     // Get all line numbers
-    for range in view.state.selection.ranges() {
-        let start = view.state.doc.char_to_line(range.from());
-        let end = view.state.doc.char_to_line(range.to());
+    for range in view.doc.state.selection.ranges() {
+        let start = view.doc.text().char_to_line(range.from());
+        let end = view.doc.text().char_to_line(range.to());
 
         for line in start..=end {
             lines.push(line)
@@ -590,13 +607,13 @@ pub fn indent(view: &mut View, _count: usize) {
     let indent = Tendril::from(" ".repeat(TAB_WIDTH));
 
     let transaction = Transaction::change(
-        &view.state,
+        &view.doc.state,
         lines.into_iter().map(|line| {
-            let pos = view.state.doc.line_to_char(line);
+            let pos = view.doc.text().line_to_char(line);
             (pos, pos, Some(indent.clone()))
         }),
     );
-    transaction.apply(&mut view.state);
+    view.doc.apply(&transaction);
     append_changes_to_history(view);
 }
 
@@ -605,7 +622,7 @@ pub fn unindent(view: &mut View, _count: usize) {
     let mut changes = Vec::with_capacity(lines.len());
 
     for line_idx in lines {
-        let line = view.state.doc.line(line_idx);
+        let line = view.doc.text().line(line_idx);
         let mut width = 0;
 
         for ch in line.chars() {
@@ -621,14 +638,14 @@ pub fn unindent(view: &mut View, _count: usize) {
         }
 
         if width > 0 {
-            let start = view.state.doc.line_to_char(line_idx);
+            let start = view.doc.text().line_to_char(line_idx);
             changes.push((start, start + width, None))
         }
     }
 
-    let transaction = Transaction::change(&view.state, changes.into_iter());
+    let transaction = Transaction::change(&view.doc.state, changes.into_iter());
 
-    transaction.apply(&mut view.state);
+    view.doc.apply(&transaction);
     append_changes_to_history(view);
 }
 
diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
new file mode 100644
index 00000000..c4b9d081
--- /dev/null
+++ b/helix-view/src/document.rs
@@ -0,0 +1,157 @@
+use anyhow::Error;
+use std::path::PathBuf;
+
+use helix_core::{
+    syntax::LOADER, ChangeSet, Diagnostic, History, Position, Range, Rope, RopeSlice, Selection,
+    State, Syntax, Transaction,
+};
+
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
+pub enum Mode {
+    Normal,
+    Insert,
+    Goto,
+}
+
+pub struct Document {
+    pub state: State, // rope + selection
+    /// File path on disk.
+    pub path: Option<PathBuf>,
+
+    /// Current editing mode.
+    pub mode: Mode,
+    pub restore_cursor: bool,
+
+    /// Tree-sitter AST tree
+    pub syntax: Option<Syntax>,
+
+    /// Pending changes since last history commit.
+    pub changes: ChangeSet,
+    pub history: History,
+    pub version: i64, // should be usize?
+    pub old_state: Option<(Rope, Selection)>,
+
+    pub diagnostics: Vec<Diagnostic>,
+}
+
+/// Like std::mem::replace() except it allows the replacement value to be mapped from the
+/// original value.
+fn take_with<T, F>(mut_ref: &mut T, closure: F)
+where
+    F: FnOnce(T) -> T,
+{
+    use std::{panic, ptr};
+
+    unsafe {
+        let old_t = ptr::read(mut_ref);
+        let new_t = panic::catch_unwind(panic::AssertUnwindSafe(|| closure(old_t)))
+            .unwrap_or_else(|_| ::std::process::abort());
+        ptr::write(mut_ref, new_t);
+    }
+}
+
+use url::Url;
+
+impl Document {
+    fn new(state: State) -> Self {
+        let changes = ChangeSet::new(&state.doc);
+        let old_state = Some((state.doc.clone(), Selection::single(0, 0)));
+
+        Self {
+            path: None,
+            state,
+            mode: Mode::Normal,
+            restore_cursor: false,
+            syntax: None,
+            changes,
+            old_state,
+            diagnostics: Vec::new(),
+            version: 0,
+            history: History::default(),
+        }
+    }
+
+    // TODO: passing scopes here is awkward
+    pub fn load(path: PathBuf, scopes: &[String]) -> Result<Self, Error> {
+        use std::{env, fs::File, io::BufReader};
+        let _current_dir = env::current_dir()?;
+
+        let doc = Rope::from_reader(BufReader::new(File::open(path.clone())?))?;
+
+        // TODO: create if not found
+
+        let mut doc = Self::new(State::new(doc));
+
+        if let Some(language_config) = LOADER.language_config_for_file_name(path.as_path()) {
+            let highlight_config = language_config.highlight_config(scopes).unwrap().unwrap();
+            // TODO: config.configure(scopes) is now delayed, is that ok?
+
+            let syntax = Syntax::new(&doc.state.doc, highlight_config.clone());
+
+            doc.syntax = Some(syntax);
+        };
+
+        // canonicalize path to absolute value
+        doc.path = Some(std::fs::canonicalize(path)?);
+
+        Ok(doc)
+    }
+
+    pub fn set_language(&mut self, scope: &str, scopes: &[String]) {
+        if let Some(language_config) = LOADER.language_config_for_scope(scope) {
+            let highlight_config = language_config.highlight_config(scopes).unwrap().unwrap();
+            // TODO: config.configure(scopes) is now delayed, is that ok?
+
+            let syntax = Syntax::new(&self.state.doc, highlight_config.clone());
+
+            self.syntax = Some(syntax);
+        };
+    }
+
+    // TODO: needs to run on undo/redo
+    pub fn apply(&mut self, transaction: &Transaction) -> bool {
+        let old_doc = self.text().clone();
+
+        let success = transaction.apply(&mut self.state);
+
+        if !transaction.changes().is_empty() {
+            // Compose this transaction with the previous one
+            take_with(&mut self.changes, |changes| {
+                changes.compose(transaction.changes().clone()).unwrap()
+            });
+
+            // update tree-sitter syntax tree
+            if let Some(syntax) = &mut self.syntax {
+                // TODO: no unwrap
+                syntax
+                    .update(&old_doc, &self.state.doc, transaction.changes())
+                    .unwrap();
+            }
+
+            // TODO: map state.diagnostics over changes::map_pos too
+        }
+        success
+    }
+
+    #[inline]
+    pub fn mode(&self) -> Mode {
+        self.mode
+    }
+
+    #[inline]
+    pub fn path(&self) -> Option<&PathBuf> {
+        self.path.as_ref()
+    }
+
+    pub fn url(&self) -> Option<Url> {
+        self.path().map(|path| Url::from_file_path(path).unwrap())
+    }
+
+    pub fn text(&self) -> &Rope {
+        &self.state.doc
+    }
+
+    // pub fn slice<R>(&self, range: R) -> RopeSlice where R: RangeBounds {
+    //     self.state.doc.slice
+    // }
+}
diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index 61abd482..02199255 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -1,6 +1,5 @@
 use crate::theme::Theme;
-use crate::View;
-use helix_core::State;
+use crate::{Document, View};
 
 use std::path::PathBuf;
 
@@ -27,8 +26,8 @@ impl Editor {
 
     pub fn open(&mut self, path: PathBuf, size: (u16, u16)) -> Result<(), Error> {
         let pos = self.views.len();
-        let state = State::load(path, self.theme.scopes())?;
-        self.views.push(View::new(state, size)?);
+        let doc = Document::load(path, self.theme.scopes())?;
+        self.views.push(View::new(doc, size)?);
         self.focus = pos;
         Ok(())
     }
diff --git a/helix-view/src/keymap.rs b/helix-view/src/keymap.rs
index 82bdbe21..347e7d77 100644
--- a/helix-view/src/keymap.rs
+++ b/helix-view/src/keymap.rs
@@ -1,4 +1,5 @@
 use crate::commands::{self, Command};
+use crate::document::Mode;
 use helix_core::{hashmap, state};
 use std::collections::HashMap;
 
@@ -88,7 +89,7 @@ pub use crossterm::event::{KeyCode, KeyEvent as Key, KeyModifiers as Modifiers};
 
 // TODO: could be trie based
 pub type Keymap = HashMap<Vec<Key>, Command>;
-pub type Keymaps = HashMap<state::Mode, Keymap>;
+pub type Keymaps = HashMap<Mode, Keymap>;
 
 macro_rules! key {
     ($ch:expr) => {
@@ -128,7 +129,7 @@ macro_rules! ctrl {
 
 pub fn default() -> Keymaps {
     hashmap!(
-        state::Mode::Normal =>
+        Mode::Normal =>
             // as long as you cast the first item, rust is able to infer the other cases
             hashmap!(
                 vec![key!('h')] => commands::move_char_left as Command,
@@ -179,7 +180,7 @@ pub fn default() -> Keymaps {
                 vec![ctrl!('u')] => commands::half_page_up,
                 vec![ctrl!('d')] => commands::half_page_down,
             ),
-            state::Mode::Insert => hashmap!(
+            Mode::Insert => hashmap!(
                 vec![Key {
                     code: KeyCode::Esc,
                     modifiers: Modifiers::NONE
@@ -201,7 +202,7 @@ pub fn default() -> Keymaps {
                     modifiers: Modifiers::NONE
                 }] => commands::insert::insert_tab,
             ),
-            state::Mode::Goto => hashmap!(
+            Mode::Goto => hashmap!(
                 vec![Key {
                     code: KeyCode::Esc,
                     modifiers: Modifiers::NONE
diff --git a/helix-view/src/lib.rs b/helix-view/src/lib.rs
index 9abe8a1a..3b923744 100644
--- a/helix-view/src/lib.rs
+++ b/helix-view/src/lib.rs
@@ -1,10 +1,12 @@
 pub mod commands;
+pub mod document;
 pub mod editor;
 pub mod keymap;
 pub mod prompt;
 pub mod theme;
 pub mod view;
 
+pub use document::Document;
 pub use editor::Editor;
 pub use theme::Theme;
 pub use view::View;
diff --git a/helix-view/src/view.rs b/helix-view/src/view.rs
index 817714c8..4cf6a2ee 100644
--- a/helix-view/src/view.rs
+++ b/helix-view/src/view.rs
@@ -2,10 +2,11 @@ use anyhow::Error;
 
 use std::borrow::Cow;
 
+use crate::Document;
 use helix_core::{
     graphemes::{grapheme_width, RopeGraphemes},
     indent::TAB_WIDTH,
-    History, Position, RopeSlice, State,
+    Position, RopeSlice,
 };
 use tui::layout::Rect;
 
@@ -14,29 +15,25 @@ pub const PADDING: usize = 5;
 // TODO: view should be View { doc: Document(state, history,..) }
 // since we can have multiple views into the same file
 pub struct View {
-    pub state: State,
+    pub doc: Document,
     pub first_line: usize,
     pub size: (u16, u16),
-
-    // TODO: Doc fields
-    pub history: History,
 }
 
 impl View {
-    pub fn new(state: State, size: (u16, u16)) -> Result<Self, Error> {
+    pub fn new(doc: Document, size: (u16, u16)) -> Result<Self, Error> {
         let view = Self {
-            state,
+            doc,
             first_line: 0,
             size,
-            history: History::default(),
         };
 
         Ok(view)
     }
 
     pub fn ensure_cursor_in_view(&mut self) {
-        let cursor = self.state.selection().cursor();
-        let line = self.state.doc().char_to_line(cursor);
+        let cursor = self.doc.state.selection().cursor();
+        let line = self.doc.text().char_to_line(cursor);
         let document_end = self.first_line + (self.size.1 as usize).saturating_sub(2);
 
         // TODO: side scroll
@@ -56,7 +53,7 @@ impl View {
         let viewport = Rect::new(6, 0, self.size.0, self.size.1 - 2); // - 2 for statusline and prompt
         std::cmp::min(
             self.first_line + (viewport.height as usize),
-            self.state.doc().len_lines() - 1,
+            self.doc.text().len_lines() - 1,
         )
     }
 
@@ -88,4 +85,25 @@ impl View {
 
         Some(Position::new(row, col))
     }
+
+    pub fn traverse<F>(&self, text: &RopeSlice, start: usize, end: usize, fun: F)
+    where
+        F: Fn(usize, usize),
+    {
+        let start = self.screen_coords_at_pos(text, start);
+        let end = self.screen_coords_at_pos(text, end);
+
+        match (start, end) {
+            // fully on screen
+            (Some(start), Some(end)) => {
+                // we want to calculate ends of lines for each char..
+            }
+            // from start to end of screen
+            (Some(start), None) => {}
+            // from start of screen to end
+            (None, Some(end)) => {}
+            // not on screen
+            (None, None) => return,
+        }
+    }
 }

From c0e17dd324f016401d56d66b7c113dada0644155 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Fri, 23 Oct 2020 11:32:25 +0900
Subject: [PATCH 11/23] Fix undo/redo not updating the syntax tree.

---
 helix-core/src/history.rs  | 46 +++++++++++++++++++++-----------------
 helix-view/src/commands.rs |  8 +++++--
 helix-view/src/document.rs |  1 -
 3 files changed, 31 insertions(+), 24 deletions(-)

diff --git a/helix-core/src/history.rs b/helix-core/src/history.rs
index e6d9a738..66445525 100644
--- a/helix-core/src/history.rs
+++ b/helix-core/src/history.rs
@@ -57,37 +57,31 @@ impl History {
         self.cursor == 0
     }
 
-    pub fn undo(&mut self, state: &mut State) {
+    // TODO: I'd like to pass Transaction by reference but it fights with the borrowck
+
+    pub fn undo(&mut self) -> Option<Transaction> {
         if self.at_root() {
             // We're at the root of undo, nothing to do.
-            return;
+            return None;
         }
 
         let current_revision = &self.revisions[self.cursor];
 
-        // TODO: pass the return value through? It should always succeed
-        let success = current_revision.revert.apply(state);
-
-        if !success {
-            panic!("Failed to apply undo!");
-        }
-
         self.cursor = current_revision.parent;
+
+        Some(current_revision.revert.clone())
     }
 
-    pub fn redo(&mut self, state: &mut State) {
+    pub fn redo(&mut self) -> Option<Transaction> {
         let current_revision = &self.revisions[self.cursor];
 
         // for now, simply pick the latest child (linear undo / redo)
         if let Some((index, transaction)) = current_revision.children.last() {
-            let success = transaction.apply(state);
-
-            if !success {
-                panic!("Failed to apply redo!");
-            }
-
             self.cursor = *index;
+
+            return Some(transaction.clone());
         }
+        None
     }
 }
 
@@ -120,17 +114,27 @@ mod test {
         assert_eq!("hello 世界!", state.doc());
 
         // ---
+        fn undo(history: &mut History, state: &mut State) {
+            if let Some(transaction) = history.undo() {
+                transaction.apply(state);
+            }
+        }
+        fn redo(history: &mut History, state: &mut State) {
+            if let Some(transaction) = history.redo() {
+                transaction.apply(state);
+            }
+        }
 
-        history.undo(&mut state);
+        undo(&mut history, &mut state);
         assert_eq!("hello world!", state.doc());
-        history.redo(&mut state);
+        redo(&mut history, &mut state);
         assert_eq!("hello 世界!", state.doc());
-        history.undo(&mut state);
-        history.undo(&mut state);
+        undo(&mut history, &mut state);
+        undo(&mut history, &mut state);
         assert_eq!("hello", state.doc());
 
         // undo at root is a no-op
-        history.undo(&mut state);
+        undo(&mut history, &mut state);
         assert_eq!("hello", state.doc());
     }
 }
diff --git a/helix-view/src/commands.rs b/helix-view/src/commands.rs
index b5350ff4..6bf89040 100644
--- a/helix-view/src/commands.rs
+++ b/helix-view/src/commands.rs
@@ -509,13 +509,17 @@ pub fn insert_char_prompt(prompt: &mut Prompt, c: char) {
 // Undo / Redo
 
 pub fn undo(view: &mut View, _count: usize) {
-    view.doc.history.undo(&mut view.doc.state);
+    if let Some(revert) = view.doc.history.undo() {
+        view.doc.apply(&revert);
+    }
 
     // TODO: each command could simply return a Option<transaction>, then the higher level handles storing it?
 }
 
 pub fn redo(view: &mut View, _count: usize) {
-    view.doc.history.redo(&mut view.doc.state);
+    if let Some(transaction) = view.doc.history.redo() {
+        view.doc.apply(&transaction);
+    }
 }
 
 // Yank / Paste
diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
index c4b9d081..04018ed6 100644
--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -108,7 +108,6 @@ impl Document {
         };
     }
 
-    // TODO: needs to run on undo/redo
     pub fn apply(&mut self, transaction: &Transaction) -> bool {
         let old_doc = self.text().clone();
 

From efc5aa2016e56e0721d125a20e3573d25af4dd76 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Fri, 23 Oct 2020 11:36:46 +0900
Subject: [PATCH 12/23] Simplify old_state handling.

---
 helix-core/src/state.rs    | 1 +
 helix-view/src/commands.rs | 8 +-------
 helix-view/src/document.rs | 4 ++--
 3 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/helix-core/src/state.rs b/helix-core/src/state.rs
index 7fd620a5..4d531aa0 100644
--- a/helix-core/src/state.rs
+++ b/helix-core/src/state.rs
@@ -4,6 +4,7 @@ use crate::{ChangeSet, Diagnostic, Position, Range, Rope, RopeSlice, Selection,
 use anyhow::Error;
 
 /// A state represents the current editor state of a single buffer.
+#[derive(Clone)]
 pub struct State {
     // TODO: fields should be private but we need to refactor commands.rs first
     pub doc: Rope,
diff --git a/helix-view/src/commands.rs b/helix-view/src/commands.rs
index 6bf89040..06c4b9e0 100644
--- a/helix-view/src/commands.rs
+++ b/helix-view/src/commands.rs
@@ -411,15 +411,9 @@ fn append_changes_to_history(view: &mut View) {
     // TODO: trigger lsp/documentDidChange with changes
 
     // HAXX: we need to reconstruct the state as it was before the changes..
-    let (doc, selection) = view.doc.old_state.take().unwrap();
-    let mut old_state = State::new(doc);
-    old_state.selection = selection;
-
+    let old_state = std::mem::replace(&mut view.doc.old_state, view.doc.state.clone());
     // TODO: take transaction by value?
     view.doc.history.commit_revision(&transaction, &old_state);
-
-    // HAXX
-    view.doc.old_state = Some((view.doc.text().clone(), view.doc.state.selection.clone()));
 }
 
 pub fn normal_mode(view: &mut View, _count: usize) {
diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
index 04018ed6..22438926 100644
--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -27,9 +27,9 @@ pub struct Document {
 
     /// Pending changes since last history commit.
     pub changes: ChangeSet,
+    pub old_state: State,
     pub history: History,
     pub version: i64, // should be usize?
-    pub old_state: Option<(Rope, Selection)>,
 
     pub diagnostics: Vec<Diagnostic>,
 }
@@ -55,7 +55,7 @@ use url::Url;
 impl Document {
     fn new(state: State) -> Self {
         let changes = ChangeSet::new(&state.doc);
-        let old_state = Some((state.doc.clone(), Selection::single(0, 0)));
+        let old_state = state.clone();
 
         Self {
             path: None,

From e4070d4de0883c3fc979b3d57b1b43ecb0a0d72f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Fri, 23 Oct 2020 11:37:32 +0900
Subject: [PATCH 13/23] Bump document version on undo/redo.

---
 helix-view/src/commands.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/helix-view/src/commands.rs b/helix-view/src/commands.rs
index 06c4b9e0..768a717e 100644
--- a/helix-view/src/commands.rs
+++ b/helix-view/src/commands.rs
@@ -504,6 +504,7 @@ pub fn insert_char_prompt(prompt: &mut Prompt, c: char) {
 
 pub fn undo(view: &mut View, _count: usize) {
     if let Some(revert) = view.doc.history.undo() {
+        view.doc.version += 1;
         view.doc.apply(&revert);
     }
 
@@ -512,6 +513,7 @@ pub fn undo(view: &mut View, _count: usize) {
 
 pub fn redo(view: &mut View, _count: usize) {
     if let Some(transaction) = view.doc.history.redo() {
+        view.doc.version += 1;
         view.doc.apply(&transaction);
     }
 }

From 55fa86248c77a01900379ec5bca668978fd5c0d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Fri, 23 Oct 2020 12:06:33 +0900
Subject: [PATCH 14/23] Introduce doc.selection()/set_selection()

---
 helix-view/src/commands.rs | 142 +++++++++++++++++--------------------
 helix-view/src/document.rs |  11 +++
 2 files changed, 78 insertions(+), 75 deletions(-)

diff --git a/helix-view/src/commands.rs b/helix-view/src/commands.rs
index 768a717e..d31aed31 100644
--- a/helix-view/src/commands.rs
+++ b/helix-view/src/commands.rs
@@ -19,40 +19,38 @@ use crate::{
 pub type Command = fn(view: &mut View, count: usize);
 
 pub fn move_char_left(view: &mut View, count: usize) {
-    // TODO: use a transaction
     let selection =
         view.doc
             .state
             .move_selection(Direction::Backward, Granularity::Character, count);
-    view.doc.state.selection = selection;
+    view.doc.set_selection(selection);
 }
 
 pub fn move_char_right(view: &mut View, count: usize) {
-    // TODO: use a transaction
-    view.doc.state.selection =
+    let selection =
         view.doc
             .state
             .move_selection(Direction::Forward, Granularity::Character, count);
+    view.doc.set_selection(selection);
 }
 
 pub fn move_line_up(view: &mut View, count: usize) {
-    // TODO: use a transaction
-    view.doc.state.selection =
-        view.doc
-            .state
-            .move_selection(Direction::Backward, Granularity::Line, count);
+    let selection = view
+        .doc
+        .state
+        .move_selection(Direction::Backward, Granularity::Line, count);
+    view.doc.set_selection(selection);
 }
 
 pub fn move_line_down(view: &mut View, count: usize) {
-    // TODO: use a transaction
-    view.doc.state.selection =
-        view.doc
-            .state
-            .move_selection(Direction::Forward, Granularity::Line, count);
+    let selection = view
+        .doc
+        .state
+        .move_selection(Direction::Forward, Granularity::Line, count);
+    view.doc.set_selection(selection);
 }
 
 pub fn move_line_end(view: &mut View, _count: usize) {
-    // TODO: use a transaction
     let lines = selection_lines(&view.doc.state);
 
     let positions = lines
@@ -68,9 +66,7 @@ pub fn move_line_end(view: &mut View, _count: usize) {
 
     let selection = Selection::new(positions.collect(), 0);
 
-    let transaction = Transaction::new(&mut view.doc.state).with_selection(selection);
-
-    view.doc.apply(&transaction);
+    view.doc.set_selection(selection);
 }
 
 pub fn move_line_start(view: &mut View, _count: usize) {
@@ -86,64 +82,58 @@ pub fn move_line_start(view: &mut View, _count: usize) {
 
     let selection = Selection::new(positions.collect(), 0);
 
-    let transaction = Transaction::new(&mut view.doc.state).with_selection(selection);
-
-    view.doc.apply(&transaction);
+    view.doc.set_selection(selection);
 }
 
 pub fn move_next_word_start(view: &mut View, count: usize) {
     let pos = view.doc.state.move_pos(
-        view.doc.state.selection.cursor(),
+        view.doc.selection().cursor(),
         Direction::Forward,
         Granularity::Word,
         count,
     );
 
-    // TODO: use a transaction
-    view.doc.state.selection = Selection::single(pos, pos);
+    view.doc.set_selection(Selection::single(pos, pos));
 }
 
 pub fn move_prev_word_start(view: &mut View, count: usize) {
     let pos = view.doc.state.move_pos(
-        view.doc.state.selection.cursor(),
+        view.doc.selection().cursor(),
         Direction::Backward,
         Granularity::Word,
         count,
     );
 
-    // TODO: use a transaction
-    view.doc.state.selection = Selection::single(pos, pos);
+    view.doc.set_selection(Selection::single(pos, pos));
 }
 
 pub fn move_next_word_end(view: &mut View, count: usize) {
     let pos = State::move_next_word_end(
         &view.doc.text().slice(..),
-        view.doc.state.selection.cursor(),
+        view.doc.selection().cursor(),
         count,
     );
 
-    // TODO: use a transaction
-    view.doc.state.selection = Selection::single(pos, pos);
+    view.doc.set_selection(Selection::single(pos, pos));
 }
 
 pub fn move_file_start(view: &mut View, _count: usize) {
-    // TODO: use a transaction
-    view.doc.state.selection = Selection::single(0, 0);
+    view.doc.set_selection(Selection::single(0, 0));
 
     view.doc.mode = Mode::Normal;
 }
 
 pub fn move_file_end(view: &mut View, _count: usize) {
-    // TODO: use a transaction
     let text = &view.doc.text();
     let last_line = text.line_to_char(text.len_lines().saturating_sub(2));
-    view.doc.state.selection = Selection::single(last_line, last_line);
+    view.doc
+        .set_selection(Selection::single(last_line, last_line));
 
     view.doc.mode = Mode::Normal;
 }
 
 pub fn check_cursor_in_view(view: &mut View) -> bool {
-    let cursor = view.doc.state.selection().cursor();
+    let cursor = view.doc.selection().cursor();
     let line = view.doc.text().char_to_line(cursor);
     let document_end = view.first_line + view.size.1.saturating_sub(1) as usize;
 
@@ -163,7 +153,7 @@ pub fn page_up(view: &mut View, _count: usize) {
     if !check_cursor_in_view(view) {
         let text = view.doc.text();
         let pos = text.line_to_char(view.last_line().saturating_sub(PADDING));
-        view.doc.state.selection = Selection::single(pos, pos);
+        view.doc.set_selection(Selection::single(pos, pos));
     }
 }
 
@@ -173,7 +163,7 @@ pub fn page_down(view: &mut View, _count: usize) {
     if view.first_line < view.doc.text().len_lines() {
         let text = view.doc.text();
         let pos = text.line_to_char(view.first_line as usize);
-        view.doc.state.selection = Selection::single(pos, pos);
+        view.doc.set_selection(Selection::single(pos, pos));
     }
 }
 
@@ -187,7 +177,7 @@ pub fn half_page_up(view: &mut View, _count: usize) {
     if !check_cursor_in_view(view) {
         let text = &view.doc.text();
         let pos = text.line_to_char(view.last_line() - PADDING);
-        view.doc.state.selection = Selection::single(pos, pos);
+        view.doc.set_selection(Selection::single(pos, pos));
     }
 }
 
@@ -199,42 +189,41 @@ pub fn half_page_down(view: &mut View, _count: usize) {
     if !check_cursor_in_view(view) {
         let text = view.doc.text();
         let pos = text.line_to_char(view.first_line as usize);
-        view.doc.state.selection = Selection::single(pos, pos);
+        view.doc.set_selection(Selection::single(pos, pos));
     }
 }
 // avoid select by default by having a visual mode switch that makes movements into selects
 
 pub fn extend_char_left(view: &mut View, count: usize) {
-    // TODO: use a transaction
     let selection =
         view.doc
             .state
             .extend_selection(Direction::Backward, Granularity::Character, count);
-    view.doc.state.selection = selection;
+    view.doc.set_selection(selection);
 }
 
 pub fn extend_char_right(view: &mut View, count: usize) {
-    // TODO: use a transaction
-    view.doc.state.selection =
+    let selection =
         view.doc
             .state
             .extend_selection(Direction::Forward, Granularity::Character, count);
+    view.doc.set_selection(selection);
 }
 
 pub fn extend_line_up(view: &mut View, count: usize) {
-    // TODO: use a transaction
-    view.doc.state.selection =
-        view.doc
-            .state
-            .extend_selection(Direction::Backward, Granularity::Line, count);
+    let selection = view
+        .doc
+        .state
+        .extend_selection(Direction::Backward, Granularity::Line, count);
+    view.doc.set_selection(selection);
 }
 
 pub fn extend_line_down(view: &mut View, count: usize) {
-    // TODO: use a transaction
-    view.doc.state.selection =
-        view.doc
-            .state
-            .extend_selection(Direction::Forward, Granularity::Line, count);
+    let selection = view
+        .doc
+        .state
+        .extend_selection(Direction::Forward, Granularity::Line, count);
+    view.doc.set_selection(selection);
 }
 
 pub fn split_selection_on_newline(view: &mut View, _count: usize) {
@@ -242,20 +231,19 @@ pub fn split_selection_on_newline(view: &mut View, _count: usize) {
     // only compile the regex once
     #[allow(clippy::trivial_regex)]
     static REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"\n").unwrap());
-    // TODO: use a transaction
-    view.doc.state.selection = selection::split_on_matches(text, view.doc.state.selection(), &REGEX)
+    let selection = selection::split_on_matches(text, view.doc.selection(), &REGEX);
+    view.doc.set_selection(selection);
 }
 
 pub fn select_line(view: &mut View, _count: usize) {
     // TODO: count
-    let pos = view.doc.state.selection().primary();
+    let pos = view.doc.selection().primary();
     let text = view.doc.text();
     let line = text.char_to_line(pos.head);
     let start = text.line_to_char(line);
     let end = text.line_to_char(line + 1).saturating_sub(1);
 
-    // TODO: use a transaction
-    view.doc.state.selection = Selection::single(start, end);
+    view.doc.set_selection(Selection::single(start, end));
 }
 
 pub fn delete_selection(view: &mut View, _count: usize) {
@@ -273,19 +261,21 @@ pub fn change_selection(view: &mut View, count: usize) {
 }
 
 pub fn collapse_selection(view: &mut View, _count: usize) {
-    view.doc.state.selection = view
+    let selection = view
         .doc
-        .state
-        .selection
-        .transform(|range| Range::new(range.head, range.head))
+        .selection()
+        .transform(|range| Range::new(range.head, range.head));
+
+    view.doc.set_selection(selection);
 }
 
 pub fn flip_selections(view: &mut View, _count: usize) {
-    view.doc.state.selection = view
+    let selection = view
         .doc
-        .state
-        .selection
-        .transform(|range| Range::new(range.head, range.anchor))
+        .selection()
+        .transform(|range| Range::new(range.head, range.anchor));
+
+    view.doc.set_selection(selection);
 }
 
 fn enter_insert_mode(view: &mut View) {
@@ -297,11 +287,11 @@ fn enter_insert_mode(view: &mut View) {
 pub fn insert_mode(view: &mut View, _count: usize) {
     enter_insert_mode(view);
 
-    view.doc.state.selection = view
+    let selection = view
         .doc
-        .state
-        .selection
-        .transform(|range| Range::new(range.to(), range.from()))
+        .selection()
+        .transform(|range| Range::new(range.to(), range.from()));
+    view.doc.set_selection(selection);
 }
 
 // inserts at the end of each selection
@@ -311,13 +301,14 @@ pub fn append_mode(view: &mut View, _count: usize) {
 
     // TODO: as transaction
     let text = &view.doc.text().slice(..);
-    view.doc.state.selection = view.doc.state.selection.transform(|range| {
+    let selection = view.doc.selection().transform(|range| {
         // TODO: to() + next char
         Range::new(
             range.from(),
             graphemes::next_grapheme_boundary(text, range.to()),
         )
-    })
+    });
+    view.doc.set_selection(selection);
 }
 
 // TODO: I, A, o and O can share a lot of the primitives.
@@ -402,7 +393,7 @@ fn append_changes_to_history(view: &mut View) {
     let changes = std::mem::replace(&mut view.doc.changes, new_changeset);
     // Instead of doing this messy merge we could always commit, and based on transaction
     // annotations either add a new layer or compose into the previous one.
-    let transaction = Transaction::from(changes).with_selection(view.doc.state.selection().clone());
+    let transaction = Transaction::from(changes).with_selection(view.doc.selection().clone());
 
     // increment document version
     // TODO: needs to happen on undo/redo too
@@ -424,12 +415,13 @@ pub fn normal_mode(view: &mut View, _count: usize) {
     // if leaving append mode, move cursor back by 1
     if view.doc.restore_cursor {
         let text = &view.doc.text().slice(..);
-        view.doc.state.selection = view.doc.state.selection.transform(|range| {
+        let selection = view.doc.selection().transform(|range| {
             Range::new(
                 range.from(),
                 graphemes::prev_grapheme_boundary(text, range.to()),
             )
         });
+        view.doc.set_selection(selection);
 
         view.doc.restore_cursor = false;
     }
@@ -587,7 +579,7 @@ fn get_lines(view: &View) -> Vec<usize> {
     let mut lines = Vec::new();
 
     // Get all line numbers
-    for range in view.doc.state.selection.ranges() {
+    for range in view.doc.selection().ranges() {
         let start = view.doc.text().char_to_line(range.from());
         let end = view.doc.text().char_to_line(range.to());
 
diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
index 22438926..a313b281 100644
--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -108,6 +108,11 @@ impl Document {
         };
     }
 
+    pub fn set_selection(&mut self, selection: Selection) {
+        // TODO: use a transaction?
+        self.state.selection = selection;
+    }
+
     pub fn apply(&mut self, transaction: &Transaction) -> bool {
         let old_doc = self.text().clone();
 
@@ -119,6 +124,8 @@ impl Document {
                 changes.compose(transaction.changes().clone()).unwrap()
             });
 
+            // TODO: when composing, replace transaction.selection too
+
             // update tree-sitter syntax tree
             if let Some(syntax) = &mut self.syntax {
                 // TODO: no unwrap
@@ -150,6 +157,10 @@ impl Document {
         &self.state.doc
     }
 
+    pub fn selection(&self) -> &Selection {
+        &self.state.selection
+    }
+
     // pub fn slice<R>(&self, range: R) -> RopeSlice where R: RangeBounds {
     //     self.state.doc.slice
     // }

From f5981f72c256a834845aad0c2947a4a20fa84d1b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Fri, 23 Oct 2020 12:09:40 +0900
Subject: [PATCH 15/23] Introduce Selection::point.

---
 helix-core/src/selection.rs |  5 +++++
 helix-view/src/commands.rs  | 19 +++++++++----------
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/helix-core/src/selection.rs b/helix-core/src/selection.rs
index 13c820f1..9413fead 100644
--- a/helix-core/src/selection.rs
+++ b/helix-core/src/selection.rs
@@ -179,6 +179,11 @@ impl Selection {
         }
     }
 
+    /// Constructs a selection holding a single cursor.
+    pub fn point(pos: usize) -> Self {
+        Self::single(pos, pos)
+    }
+
     #[must_use]
     pub fn new(ranges: SmallVec<[Range; 1]>, primary_index: usize) -> Self {
         fn normalize(mut ranges: SmallVec<[Range; 1]>, mut primary_index: usize) -> Selection {
diff --git a/helix-view/src/commands.rs b/helix-view/src/commands.rs
index d31aed31..52e09dd6 100644
--- a/helix-view/src/commands.rs
+++ b/helix-view/src/commands.rs
@@ -93,7 +93,7 @@ pub fn move_next_word_start(view: &mut View, count: usize) {
         count,
     );
 
-    view.doc.set_selection(Selection::single(pos, pos));
+    view.doc.set_selection(Selection::point(pos));
 }
 
 pub fn move_prev_word_start(view: &mut View, count: usize) {
@@ -104,7 +104,7 @@ pub fn move_prev_word_start(view: &mut View, count: usize) {
         count,
     );
 
-    view.doc.set_selection(Selection::single(pos, pos));
+    view.doc.set_selection(Selection::point(pos));
 }
 
 pub fn move_next_word_end(view: &mut View, count: usize) {
@@ -114,11 +114,11 @@ pub fn move_next_word_end(view: &mut View, count: usize) {
         count,
     );
 
-    view.doc.set_selection(Selection::single(pos, pos));
+    view.doc.set_selection(Selection::point(pos));
 }
 
 pub fn move_file_start(view: &mut View, _count: usize) {
-    view.doc.set_selection(Selection::single(0, 0));
+    view.doc.set_selection(Selection::point(0));
 
     view.doc.mode = Mode::Normal;
 }
@@ -126,8 +126,7 @@ pub fn move_file_start(view: &mut View, _count: usize) {
 pub fn move_file_end(view: &mut View, _count: usize) {
     let text = &view.doc.text();
     let last_line = text.line_to_char(text.len_lines().saturating_sub(2));
-    view.doc
-        .set_selection(Selection::single(last_line, last_line));
+    view.doc.set_selection(Selection::point(last_line));
 
     view.doc.mode = Mode::Normal;
 }
@@ -153,7 +152,7 @@ pub fn page_up(view: &mut View, _count: usize) {
     if !check_cursor_in_view(view) {
         let text = view.doc.text();
         let pos = text.line_to_char(view.last_line().saturating_sub(PADDING));
-        view.doc.set_selection(Selection::single(pos, pos));
+        view.doc.set_selection(Selection::point(pos));
     }
 }
 
@@ -163,7 +162,7 @@ pub fn page_down(view: &mut View, _count: usize) {
     if view.first_line < view.doc.text().len_lines() {
         let text = view.doc.text();
         let pos = text.line_to_char(view.first_line as usize);
-        view.doc.set_selection(Selection::single(pos, pos));
+        view.doc.set_selection(Selection::point(pos));
     }
 }
 
@@ -177,7 +176,7 @@ pub fn half_page_up(view: &mut View, _count: usize) {
     if !check_cursor_in_view(view) {
         let text = &view.doc.text();
         let pos = text.line_to_char(view.last_line() - PADDING);
-        view.doc.set_selection(Selection::single(pos, pos));
+        view.doc.set_selection(Selection::point(pos));
     }
 }
 
@@ -189,7 +188,7 @@ pub fn half_page_down(view: &mut View, _count: usize) {
     if !check_cursor_in_view(view) {
         let text = view.doc.text();
         let pos = text.line_to_char(view.first_line as usize);
-        view.doc.set_selection(Selection::single(pos, pos));
+        view.doc.set_selection(Selection::point(pos));
     }
 }
 // avoid select by default by having a visual mode switch that makes movements into selects

From eff6fac9ece0700f0ed8eb0a230b6816fa7cece7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Fri, 23 Oct 2020 13:51:08 +0900
Subject: [PATCH 16/23] clippy lint

---
 helix-lsp/src/transport.rs |  3 +--
 helix-view/src/document.rs |  2 ++
 helix-view/src/editor.rs   |  6 ++++++
 helix-view/src/keymap.rs   |  2 +-
 helix-view/src/view.rs     | 38 +++++++++++++++++++-------------------
 5 files changed, 29 insertions(+), 22 deletions(-)

diff --git a/helix-lsp/src/transport.rs b/helix-lsp/src/transport.rs
index 38c3bb57..b30a8a6e 100644
--- a/helix-lsp/src/transport.rs
+++ b/helix-lsp/src/transport.rs
@@ -138,11 +138,10 @@ impl Transport {
                 // println!("<- {} {:?}", method, notification);
                 self.incoming.send(notification).await?;
             }
-            Message::Call(call) => {
+            Message::Call(_call) => {
                 // println!("<- {:?}", call);
                 // dispatch
             }
-            _ => unreachable!(),
         };
         Ok(())
     }
diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
index a313b281..710ea4f8 100644
--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -164,4 +164,6 @@ impl Document {
     // pub fn slice<R>(&self, range: R) -> RopeSlice where R: RangeBounds {
     //     self.state.doc.slice
     // }
+
+    // TODO: transact(Fn) ?
 }
diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index 02199255..9fb2ae36 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -12,6 +12,12 @@ pub struct Editor {
     pub theme: Theme, // TODO: share one instance
 }
 
+impl Default for Editor {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl Editor {
     pub fn new() -> Self {
         let theme = Theme::default();
diff --git a/helix-view/src/keymap.rs b/helix-view/src/keymap.rs
index 347e7d77..aaba34a6 100644
--- a/helix-view/src/keymap.rs
+++ b/helix-view/src/keymap.rs
@@ -1,6 +1,6 @@
 use crate::commands::{self, Command};
 use crate::document::Mode;
-use helix_core::{hashmap, state};
+use helix_core::hashmap;
 use std::collections::HashMap;
 
 // Kakoune-inspired:
diff --git a/helix-view/src/view.rs b/helix-view/src/view.rs
index 4cf6a2ee..df41e3ae 100644
--- a/helix-view/src/view.rs
+++ b/helix-view/src/view.rs
@@ -86,24 +86,24 @@ impl View {
         Some(Position::new(row, col))
     }
 
-    pub fn traverse<F>(&self, text: &RopeSlice, start: usize, end: usize, fun: F)
-    where
-        F: Fn(usize, usize),
-    {
-        let start = self.screen_coords_at_pos(text, start);
-        let end = self.screen_coords_at_pos(text, end);
+    // pub fn traverse<F>(&self, text: &RopeSlice, start: usize, end: usize, fun: F)
+    // where
+    //     F: Fn(usize, usize),
+    // {
+    //     let start = self.screen_coords_at_pos(text, start);
+    //     let end = self.screen_coords_at_pos(text, end);
 
-        match (start, end) {
-            // fully on screen
-            (Some(start), Some(end)) => {
-                // we want to calculate ends of lines for each char..
-            }
-            // from start to end of screen
-            (Some(start), None) => {}
-            // from start of screen to end
-            (None, Some(end)) => {}
-            // not on screen
-            (None, None) => return,
-        }
-    }
+    //     match (start, end) {
+    //         // fully on screen
+    //         (Some(start), Some(end)) => {
+    //             // we want to calculate ends of lines for each char..
+    //         }
+    //         // from start to end of screen
+    //         (Some(start), None) => {}
+    //         // from start of screen to end
+    //         (None, Some(end)) => {}
+    //         // not on screen
+    //         (None, None) => return,
+    //     }
+    // }
 }

From af1924404adac399c351a17bc0f43b5e2889abbb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Fri, 23 Oct 2020 14:33:09 +0900
Subject: [PATCH 17/23] Configure logging (-vv for debug level logs)

---
 Cargo.lock                 | 68 ++++++++++++++++++++++++++++++++++++--
 helix-lsp/Cargo.toml       |  7 ++--
 helix-lsp/log              | 45 -------------------------
 helix-lsp/src/transport.rs | 12 ++++---
 helix-term/Cargo.toml      |  7 +++-
 helix-term/src/main.rs     | 44 ++++++++++++++++++++++++
 6 files changed, 126 insertions(+), 57 deletions(-)
 delete mode 100644 helix-lsp/log

diff --git a/Cargo.lock b/Cargo.lock
index 29a86a36..bc3da508 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -208,6 +208,19 @@ version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 
+[[package]]
+name = "chrono"
+version = "0.4.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "670ad68c9088c2a963aaa298cb369688cf3f9465ce5e2d4ca10e6e0098a1ce73"
+dependencies = [
+ "libc",
+ "num-integer",
+ "num-traits",
+ "time",
+ "winapi",
+]
+
 [[package]]
 name = "clap"
 version = "3.0.0-beta.2"
@@ -320,6 +333,15 @@ dependencies = [
  "instant",
 ]
 
+[[package]]
+name = "fern"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8c9a4820f0ccc8a7afd67c39a0f1a0f4b07ca1725164271a64939d7aeb9af065"
+dependencies = [
+ "log",
+]
+
 [[package]]
 name = "futf"
 version = "0.1.4"
@@ -408,7 +430,7 @@ checksum = "fc587bc0ec293155d5bfa6b9891ec18a1e330c234f896ea47fbada4cadbe47e6"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi",
+ "wasi 0.9.0+wasi-snapshot-preview1",
 ]
 
 [[package]]
@@ -449,6 +471,7 @@ dependencies = [
  "helix-core",
  "helix-view",
  "jsonrpc-core",
+ "log",
  "lsp-types",
  "pathdiff",
  "serde",
@@ -472,12 +495,15 @@ name = "helix-term"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "chrono",
  "clap",
  "crossterm",
+ "fern",
  "futures-util",
  "helix-core",
  "helix-lsp",
  "helix-view",
+ "log",
  "num_cpus",
  "smol",
  "tui",
@@ -672,6 +698,25 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "num-integer"
+version = "0.1.43"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8d59457e662d541ba17869cf51cf177c0b5f0cbf476c66bdc90bf1edac4f875b"
+dependencies = [
+ "autocfg",
+ "num-traits",
+]
+
+[[package]]
+name = "num-traits"
+version = "0.2.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac267bcc07f48ee5f8935ab0d24f316fb722d7a1292e2913f0cc196b29ffd611"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "num_cpus"
 version = "1.13.0"
@@ -997,9 +1042,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.45"
+version = "1.0.46"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ea9c5432ff16d6152371f808fb5a871cd67368171b09bb21b43df8e4a47a3556"
+checksum = "5ad5de3220ea04da322618ded2c42233d02baca219d6f160a3e9c87cda16c942"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1054,6 +1099,17 @@ dependencies = [
  "lazy_static",
 ]
 
+[[package]]
+name = "time"
+version = "0.1.44"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6db9e6914ab8b1ae1c260a4ae7a49b6c5611b40328a735b21862567685e73255"
+dependencies = [
+ "libc",
+ "wasi 0.10.0+wasi-snapshot-preview1",
+ "winapi",
+]
+
 [[package]]
 name = "tinyvec"
 version = "0.3.4"
@@ -1160,6 +1216,12 @@ version = "0.9.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
 
+[[package]]
+name = "wasi"
+version = "0.10.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a143597ca7c7793eff794def352d41792a93c481eb1042423ff7ff72ba2c31f"
+
 [[package]]
 name = "wepoll-sys"
 version = "3.0.1"
diff --git a/helix-lsp/Cargo.toml b/helix-lsp/Cargo.toml
index 351c3b0e..ffd909a4 100644
--- a/helix-lsp/Cargo.toml
+++ b/helix-lsp/Cargo.toml
@@ -13,12 +13,13 @@ helix-view = { path = "../helix-view" }
 lsp-types = { version = "0.82", features = ["proposed"] }
 smol = "1.2"
 url = "2"
-pathdiff = "0.2.0"
-shellexpand = "2.0.0"
+pathdiff = "0.2"
+shellexpand = "2.0"
 glob = "0.3"
 anyhow = "1"
 serde_json = "1.0"
 serde = { version = "1.0", features = ["derive"] }
 jsonrpc-core = "15.1"
 futures-util = "0.3"
-thiserror = "1.0.21"
+thiserror = "1"
+log = "0.4"
diff --git a/helix-lsp/log b/helix-lsp/log
deleted file mode 100644
index d8370f16..00000000
--- a/helix-lsp/log
+++ /dev/null
@@ -1,45 +0,0 @@
-Sun Oct 18 21:15:33 2020:["lsp#register_server", "server registered", "typescript-language-server"]
-Sun Oct 18 21:15:33 2020:["lsp#register_server", "server registered", "elixir-ls"]
-Sun Oct 18 21:15:33 2020:["lsp#register_server", "server registered", "vue-language-server"]
-Sun Oct 18 21:15:33 2020:["lsp#register_server", "server registered", "rust-analyzer"]
-Sun Oct 18 21:15:33 2020:["s:on_text_document_did_open()", 1, "", "/Users/speed/src/helix/helix-lsp", ""]
-Sun Oct 18 21:15:34 2020:["s:on_text_document_did_close()", 1]
-Sun Oct 18 21:15:34 2020:["s:on_text_document_did_open()", 1, "rust", "/Users/speed/src/helix", "file:///Users/speed/src/helix/helix-lsp/src/lib.rs"]
-Sun Oct 18 21:15:34 2020:["Starting server", "rust-analyzer", ["rust-analyzer"]]
-Sun Oct 18 21:15:34 2020:[{"response": {"data": {"__data__": "vim-lsp", "lsp_id": 7, "server_name": "rust-analyzer"}, "message": "started lsp server successfully"}}]
-Sun Oct 18 21:15:34 2020:["--->", 7, "rust-analyzer", {"method": "initialize", "params": {"rootUri": "file:///Users/speed/src/helix/helix-lsp", "capabilities": {"workspace": {"configuration": true, "applyEdit": true}, "textDocument": {"implementation": {"linkSupport": true}, "documentSymbol": {"symbolKind": {"valueSet": [10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 1, 2, 3, 4, 5, 6, 7, 8, 9]}, "hierarchicalDocumentSymbolSupport": false}, "semanticHighlightingCapabilities": {"semanticHighlighting": false}, "codeAction": {"codeActionLiteralSupport": {"codeActionKind": {"valueSet": ["", "quickfix", "refactor", "refactor.extract", "refactor.inline", "refactor.rewrite", "source", "source.organizeImports"]}}, "dynamicRegistration": false}, "completion": {"completionItem": {"snippetSupport": false, "documentationFormat": ["plaintext"]}, "completionItemKind": {"valueSet": [10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 1, 2, 3, 4, 5, 6, 7, 8, 9]}}, "foldingRange": {"lineFoldingOnly": true}, "typeDefinition": {"linkSupport": true}, "typeHierarchy": false, "declaration": {"linkSupport": true}, "definition": {"linkSupport": true}}}, "rootPath": "/Users/speed/src/helix/helix-lsp", "processId": 22973, "trace": "off"}}]
-Sun Oct 18 21:15:34 2020:["<---", 7, "rust-analyzer", {"response": {"id": 1, "jsonrpc": "2.0", "result": {"capabilities": {"documentHighlightProvider": true, "hoverProvider": true, "typeDefinitionProvider": true, "workspaceSymbolProvider": true, "referencesProvider": true, "signatureHelpProvider": {"triggerCharacters": ["(", ","]}, "foldingRangeProvider": true, "callHierarchyProvider": true, "codeActionProvider": {"codeActionKinds": ["", "quickfix", "refactor", "refactor.extract", "refactor.inline", "refactor.rewrite"]}, "textDocumentSync": {"save": {}, "change": 2, "openClose": true}, "codeLensProvider": {"resolveProvider": true}, "implementationProvider": true, "documentOnTypeFormattingProvider": {"moreTriggerCharacter": [".", ">"], "firstTriggerCharacter": "="}, "definitionProvider": true, "selectionRangeProvider": true, "semanticTokensProvider": {"legend": {"tokenTypes": ["comment", "keyword", "string", "number", "regexp", "operator", "namespace", "type", "struct", "class", "interface", "enum", "typeParameter", "function", "member", "property", "macro", "variable", "parameter", "label", "attribute", "boolean", "builtinType", "enumMember", "escapeSequence", "formatSpecifier", "generic", "lifetime", "punctuation", "selfKeyword", "typeAlias", "union", "unresolvedReference"], "tokenModifiers": ["documentation", "declaration", "definition", "static", "abstract", "deprecated", "readonly", "constant", "controlFlow", "injected", "mutable", "unsafe", "attribute"]}, "documentProvider": true, "rangeProvider": true}, "documentFormattingProvider": true, "documentSymbolProvider": true, "experimental": {"parentModule": true, "onEnter": true, "runnables": {"kinds": ["cargo"]}, "ssr": true, "joinLines": true}, "renameProvider": {"prepareProvider": true}, "completionProvider": {"triggerCharacters": [":", "."]}}, "serverInfo": {"version": "???????", "name": "rust-analyzer"}}}, "request": {"id": 1, "jsonrpc": "2.0", "method": "initialize", "params": {"rootUri": "file:///Users/speed/src/helix/helix-lsp", "capabilities": {"workspace": {"configuration": true, "applyEdit": true}, "textDocument": {"implementation": {"linkSupport": true}, "documentSymbol": {"symbolKind": {"valueSet": [10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 1, 2, 3, 4, 5, 6, 7, 8, 9]}, "hierarchicalDocumentSymbolSupport": false}, "semanticHighlightingCapabilities": {"semanticHighlighting": false}, "codeAction": {"codeActionLiteralSupport": {"codeActionKind": {"valueSet": ["", "quickfix", "refactor", "refactor.extract", "refactor.inline", "refactor.rewrite", "source", "source.organizeImports"]}}, "dynamicRegistration": false}, "completion": {"completionItem": {"snippetSupport": false, "documentationFormat": ["plaintext"]}, "completionItemKind": {"valueSet": [10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 1, 2, 3, 4, 5, 6, 7, 8, 9]}}, "foldingRange": {"lineFoldingOnly": true}, "typeDefinition": {"linkSupport": true}, "typeHierarchy": false, "declaration": {"linkSupport": true}, "definition": {"linkSupport": true}}}, "rootPath": "/Users/speed/src/helix/helix-lsp", "processId": 22973, "trace": "off"}}}]
-Sun Oct 18 21:15:34 2020:["--->", 7, "rust-analyzer", {"method": "initialized", "params": {}}]
-Sun Oct 18 21:15:34 2020:[{"response": {"data": {"__data__": "vim-lsp", "server_name": "rust-analyzer"}, "message": "configuration sent"}}]
-Sun Oct 18 21:15:34 2020:["s:update_file_content()", 1]
-Sun Oct 18 21:15:34 2020:["--->", 7, "rust-analyzer", {"method": "textDocument/didOpen", "params": {"textDocument": {"uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1, "languageId": "rust", "text": "use std::collections::HashMap;\n\nuse jsonrpc_core as jsonrpc;\nuse lsp_types as lsp;\n\nuse serde::{Deserialize, Serialize};\nuse serde_json::Value;\n\nuse smol::channel::{Receiver, Sender};\nuse smol::io::{BufReader, BufWriter};\nuse smol::prelude::*;\nuse smol::process::{Child, ChildStderr, ChildStdin, ChildStdout, Command, Stdio};\nuse smol::Executor;\n\nuse futures_util::{select, FutureExt};\n\n/// A type representing all possible values sent from the server to the client.\n#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]\n#[serde(deny_unknown_fields)]\n#[serde(untagged)]\nenum Message {\n    /// A regular JSON-RPC request output (single response).\n    Output(jsonrpc::Output),\n    /// A notification.\n    Notification(jsonrpc::Notification),\n    /// A JSON-RPC request\n    Call(jsonrpc::Call),\n}\n\npub struct Client {\n    process: Child,\n    stderr: BufReader<ChildStderr>,\n    outgoing: Sender<Payload>,\n\n    pub request_counter: u64,\n\n    capabilities: Option<lsp::ServerCapabilities>,\n}\n\nimpl Client {\n    pub fn start(ex: &Executor, cmd: &str, args: &[String]) -> Self {\n        let mut process = Command::new(cmd)\n            .args(args)\n            .stdin(Stdio::piped())\n            .stdout(Stdio::piped())\n            .stderr(Stdio::piped())\n            .spawn()\n            .expect(\"Failed to start language server\");\n        // smol makes sure the process is reaped on drop, but using kill_on_drop(true) maybe?\n\n        // TODO: do we need bufreader/writer here? or do we use async wrappers on unblock?\n        let writer = BufWriter::new(process.stdin.take().expect(\"Failed to open stdin\"));\n        let reader = BufReader::new(process.stdout.take().expect(\"Failed to open stdout\"));\n        let stderr = BufReader::new(process.stderr.take().expect(\"Failed to open stderr\"));\n\n        let (incoming, outgoing) = Transport::start(ex, reader, writer);\n\n        Client {\n            process,\n            stderr,\n            outgoing,\n\n            request_counter: 0,\n\n            capabilities: None,\n        }\n    }\n\n    fn next_request_id(&mut self) -> jsonrpc::Id {\n        let id = jsonrpc::Id::Num(self.request_counter);\n        self.request_counter += 1;\n        id\n    }\n\n    fn to_params(value: Value) -> anyhow::Result<jsonrpc::Params> {\n        use jsonrpc::Params;\n\n        let params = match value {\n            Value::Null => Params::None,\n            Value::Bool(_) | Value::Number(_) | Value::String(_) => Params::Array(vec![value]),\n            Value::Array(vec) => Params::Array(vec),\n            Value::Object(map) => Params::Map(map),\n        };\n\n        Ok(params)\n    }\n\n    pub async fn request<R: lsp::request::Request>(\n        &mut self,\n        params: R::Params,\n    ) -> anyhow::Result<R::Result>\n    where\n        R::Params: serde::Serialize,\n        R::Result: core::fmt::Debug, // TODO: temporary\n    {\n        let params = serde_json::to_value(params)?;\n\n        let request = jsonrpc::MethodCall {\n            jsonrpc: Some(jsonrpc::Version::V2),\n            id: self.next_request_id(),\n            method: R::METHOD.to_string(),\n            params: Self::to_params(params)?,\n        };\n\n        let (tx, rx) = smol::channel::bounded::<anyhow::Result<Value>>(1);\n\n        self.outgoing\n            .send(Payload::Request {\n                chan: tx,\n                value: request,\n            })\n            .await?;\n\n        let response = rx.recv().await??;\n\n        let response = serde_json::from_value(response)?;\n\n        // TODO: we should pass request to a sender thread via a channel\n        // so it can't be interleaved\n\n        // TODO: responses can be out of order, we need to register a single shot response channel\n\n        Ok(response)\n    }\n\n    pub async fn notify<R: lsp::notification::Notification>(\n        &mut self,\n        params: R::Params,\n    ) -> anyhow::Result<()>\n    where\n        R::Params: serde::Serialize,\n    {\n        let params = serde_json::to_value(params)?;\n\n        let notification = jsonrpc::Notification {\n            jsonrpc: Some(jsonrpc::Version::V2),\n            method: R::METHOD.to_string(),\n            params: Self::to_params(params)?,\n        };\n\n        self.outgoing\n            .send(Payload::Notification(notification))\n            .await?;\n\n        Ok(())\n    }\n\n    // -------------------------------------------------------------------------------------------\n    // General messages\n    // -------------------------------------------------------------------------------------------\n\n    pub async fn initialize(&mut self) -> anyhow::Result<()> {\n        // TODO: delay any requests that are triggered prior to initialize\n\n        #[allow(deprecated)]\n        let params = lsp::InitializeParams {\n            process_id: Some(u64::from(std::process::id())),\n            root_path: None,\n            // root_uri: Some(lsp_types::Url::parse(\"file://localhost/\")?),\n            root_uri: None, // set to project root in the future\n            initialization_options: None,\n            capabilities: lsp::ClientCapabilities::default(),\n            trace: None,\n            workspace_folders: None,\n            client_info: None,\n        };\n\n        let response = self.request::<lsp::request::Initialize>(params).await?;\n        self.capabilities = Some(response.capabilities);\n\n        // next up, notify<initialized>\n        self.notify::<lsp::notification::Initialized>(lsp::InitializedParams {})\n            .await?;\n\n        Ok(())\n    }\n\n    pub async fn shutdown(&mut self) -> anyhow::Result<()> {\n        self.request::<lsp::request::Shutdown>(()).await\n    }\n\n    pub async fn exit(&mut self) -> anyhow::Result<()> {\n        self.notify::<lsp::notification::Exit>(()).await\n    }\n\n    // -------------------------------------------------------------------------------------------\n    // Text document\n    // -------------------------------------------------------------------------------------------\n\n    pub async fn text_document_did_open(\n        &mut self,\n        state: &helix_core::State,\n    ) -> anyhow::Result<()> {\n        self.notify::<lsp::notification::DidOpenTextDocument>(lsp::DidOpenTextDocumentParams {\n            text_document: lsp::TextDocumentItem {\n                uri: lsp::Url::from_file_path(\n                    std::fs::canonicalize(state.path.as_ref().unwrap()).unwrap(),\n                )\n                .unwrap(),\n                language_id: \"rust\".to_string(), // TODO: hardcoded for now\n                version: 0,\n                text: String::from(&state.doc),\n            },\n        })\n        .await\n    }\n\n    // TODO: trigger any time history.commit_revision happens\n    pub async fn text_document_did_change(\n        &mut self,\n        state: &helix_core::State,\n    ) -> anyhow::Result<()> {\n        self.notify::<lsp::notification::DidSaveTextDocument>(lsp::DidSaveTextDocumentParams {\n            text_document: lsp::TextDocumentIdentifier::new(\n                lsp::Url::from_file_path(state.path.as_ref().unwrap()).unwrap(),\n            ),\n            text: None, // TODO?\n        })\n        .await\n    }\n\n    pub async fn text_document_did_close(&mut self) -> anyhow::Result<()> {\n        unimplemented!()\n    }\n\n    // will_save / will_save_wait_until\n\n    pub async fn text_document_did_save(&mut self) -> anyhow::Result<()> {\n        unimplemented!()\n    }\n}\n\nenum Payload {\n    Request {\n        chan: Sender<anyhow::Result<Value>>,\n        value: jsonrpc::MethodCall,\n    },\n    Notification(jsonrpc::Notification),\n}\n\nstruct Transport {\n    incoming: Sender<Message>,\n    outgoing: Receiver<Payload>,\n\n    pending_requests: HashMap<jsonrpc::Id, Sender<anyhow::Result<Value>>>,\n    headers: HashMap<String, String>,\n\n    writer: BufWriter<ChildStdin>,\n    reader: BufReader<ChildStdout>,\n}\n\nimpl Transport {\n    pub fn start(\n        ex: &Executor,\n        reader: BufReader<ChildStdout>,\n        writer: BufWriter<ChildStdin>,\n    ) -> (Receiver<Message>, Sender<Payload>) {\n        let (incoming, rx) = smol::channel::unbounded();\n        let (tx, outgoing) = smol::channel::unbounded();\n\n        let transport = Self {\n            reader,\n            writer,\n            incoming,\n            outgoing,\n            pending_requests: Default::default(),\n            headers: Default::default(),\n        };\n\n        ex.spawn(transport.duplex()).detach();\n\n        (rx, tx)\n    }\n\n    async fn recv(\n        reader: &mut (impl AsyncBufRead + Unpin),\n        headers: &mut HashMap<String, String>,\n    ) -> Result<Message, std::io::Error> {\n        // read headers\n        loop {\n            let mut header = String::new();\n            // detect pipe closed if 0\n            reader.read_line(&mut header).await?;\n            let header = header.trim();\n\n            if header.is_empty() {\n                break;\n            }\n\n            let parts: Vec<&str> = header.split(\": \").collect();\n            if parts.len() != 2 {\n                // return Err(Error::new(ErrorKind::Other, \"Failed to parse header\"));\n                panic!()\n            }\n            headers.insert(parts[0].to_string(), parts[1].to_string());\n        }\n\n        // find content-length\n        let content_length = headers.get(\"Content-Length\").unwrap().parse().unwrap();\n\n        let mut content = vec![0; content_length];\n        reader.read_exact(&mut content).await?;\n        let msg = String::from_utf8(content).unwrap();\n\n        // read data\n\n        // try parsing as output (server response) or call (server request)\n        let output: serde_json::Result<Message> = serde_json::from_str(&msg);\n\n        Ok(output?)\n    }\n\n    pub async fn send_payload(&mut self, payload: Payload) -> anyhow::Result<()> {\n        match payload {\n            Payload::Request { chan, value } => {\n                self.pending_requests.insert(value.id.clone(), chan);\n\n                let json = serde_json::to_string(&value)?;\n                self.send(json).await\n            }\n            Payload::Notification(value) => {\n                let json = serde_json::to_string(&value)?;\n                self.send(json).await\n            }\n        }\n    }\n\n    pub async fn send(&mut self, request: String) -> anyhow::Result<()> {\n        println!(\"-> {}\", request);\n\n        // send the headers\n        self.writer\n            .write_all(format!(\"Content-Length: {}\\r\\n\\r\\n\", request.len()).as_bytes())\n            .await?;\n\n        // send the body\n        self.writer.write_all(request.as_bytes()).await?;\n\n        self.writer.flush().await?;\n\n        Ok(())\n    }\n\n    pub async fn recv_response(&mut self, output: jsonrpc::Output) -> anyhow::Result<()> {\n        match output {\n            jsonrpc::Output::Success(jsonrpc::Success { id, result, .. }) => {\n                println!(\"<- {}\", result);\n\n                let tx = self\n                    .pending_requests\n                    .remove(&id)\n                    .expect(\"pending_request with id not found!\");\n                tx.send(Ok(result)).await?;\n            }\n            jsonrpc::Output::Failure(_) => panic!(\"recv fail\"),\n            msg => unimplemented!(\"{:?}\", msg),\n        }\n        Ok(())\n    }\n\n    pub async fn duplex(mut self) {\n        loop {\n            select! {\n                // client -> server\n                msg = self.outgoing.next().fuse() => {\n                    if msg.is_none() {\n                        break;\n                    }\n                    let msg = msg.unwrap();\n\n                    self.send_payload(msg).await.unwrap();\n                }\n                // server <- client\n                msg = Self::recv(&mut self.reader, &mut self.headers).fuse() => {\n                    if msg.is_err() {\n                        break;\n                    }\n                    let msg = msg.unwrap();\n\n                    match msg {\n                        Message::Output(output) => self.recv_response(output).await.unwrap(),\n                        Message::Notification(_) => {\n                            // dispatch\n                        }\n                        Message::Call(_) => {\n                            // dispatch\n                        }\n                    };\n                }\n            }\n        }\n    }\n}\n"}}}]
-Sun Oct 18 21:15:34 2020:[{"response": {"data": {"__data__": "vim-lsp", "server_name": "rust-analyzer"}, "message": "server already started"}}]
-Sun Oct 18 21:15:34 2020:[{"response": {"data": {"__data__": "vim-lsp", "init_result": {"id": 1, "jsonrpc": "2.0", "result": {"capabilities": {"documentHighlightProvider": true, "hoverProvider": true, "typeDefinitionProvider": true, "workspaceSymbolProvider": true, "referencesProvider": true, "signatureHelpProvider": {"triggerCharacters": ["(", ","]}, "foldingRangeProvider": true, "callHierarchyProvider": true, "codeActionProvider": {"codeActionKinds": ["", "quickfix", "refactor", "refactor.extract", "refactor.inline", "refactor.rewrite"]}, "textDocumentSync": {"save": {}, "change": 2, "openClose": true}, "codeLensProvider": {"resolveProvider": true}, "implementationProvider": true, "documentOnTypeFormattingProvider": {"moreTriggerCharacter": [".", ">"], "firstTriggerCharacter": "="}, "definitionProvider": true, "selectionRangeProvider": true, "semanticTokensProvider": {"legend": {"tokenTypes": ["comment", "keyword", "string", "number", "regexp", "operator", "namespace", "type", "struct", "class", "interface", "enum", "typeParameter", "function", "member", "property", "macro", "variable", "parameter", "label", "attribute", "boolean", "builtinType", "enumMember", "escapeSequence", "formatSpecifier", "generic", "lifetime", "punctuation", "selfKeyword", "typeAlias", "union", "unresolvedReference"], "tokenModifiers": ["documentation", "declaration", "definition", "static", "abstract", "deprecated", "readonly", "constant", "controlFlow", "injected", "mutable", "unsafe", "attribute"]}, "documentProvider": true, "rangeProvider": true}, "documentFormattingProvider": true, "documentSymbolProvider": true, "experimental": {"parentModule": true, "onEnter": true, "runnables": {"kinds": ["cargo"]}, "ssr": true, "joinLines": true}, "renameProvider": {"prepareProvider": true}, "completionProvider": {"triggerCharacters": [":", "."]}}, "serverInfo": {"version": "???????", "name": "rust-analyzer"}}}, "server_name": "rust-analyzer"}, "message": "lsp server already initialized"}}]
-Sun Oct 18 21:15:34 2020:[{"response": {"data": {"__data__": "vim-lsp", "server_name": "rust-analyzer"}, "message": "configuration sent"}}]
-Sun Oct 18 21:15:34 2020:[{"response": {"data": {"path": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "__data__": "vim-lsp", "server_name": "rust-analyzer"}, "message": "already opened"}}]
-Sun Oct 18 21:15:34 2020:[{"response": {"data": {"path": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "__data__": "vim-lsp", "server_name": "rust-analyzer"}, "message": "not dirty"}}]
-Sun Oct 18 21:15:34 2020:["--->", 7, "rust-analyzer", {"method": "textDocument/foldingRange", "on_notification": "---funcref---", "bufnr": 1, "params": {"textDocument": {"uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs"}}, "sync": 0}]
-Sun Oct 18 21:15:34 2020:[{"response": {"data": {"path": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "__data__": "vim-lsp", "filetype": "rust", "server_name": "rust-analyzer"}, "message": "textDocument/open sent"}}]
-Sun Oct 18 21:15:34 2020:[{"response": {"data": {"path": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "__data__": "vim-lsp", "server_name": "rust-analyzer"}, "message": "not dirty"}}]
-Sun Oct 18 21:15:35 2020:["<---", 7, {"id": 0, "jsonrpc": "2.0", "method": "client/registerCapability", "params": {"registrations": [{"id": "textDocument/didSave", "registerOptions": {"includeText": false, "documentSelector": [{"pattern": "**/*.rs"}, {"pattern": "**/Cargo.toml"}, {"pattern": "**/Cargo.lock"}]}, "method": "textDocument/didSave"}]}}]
-Sun Oct 18 21:15:35 2020:["--->", 7, "rust-analyzer", {"id": 0, "error": {"code": -32601, "message": "Method not found"}}]
-Sun Oct 18 21:15:35 2020:["<---", 7, "rust-analyzer", {"response": {"id": 2, "jsonrpc": "2.0", "result": [{"startLine": 2, "kind": "imports", "endLine": 3}, {"startLine": 5, "kind": "imports", "endLine": 6}, {"startLine": 8, "kind": "imports", "endLine": 12}, {"startLine": 20, "endLine": 27}, {"startLine": 29, "endLine": 37}, {"startLine": 39, "endLine": 230}, {"startLine": 40, "endLine": 66}, {"startLine": 57, "endLine": 65}, {"startLine": 68, "endLine": 72}, {"startLine": 74, "endLine": 85}, {"startLine": 77, "endLine": 81}, {"startLine": 87, "endLine": 89}, {"startLine": 94, "endLine": 123}, {"startLine": 97, "endLine": 101}, {"startLine": 107, "endLine": 110}, {"startLine": 107, "endLine": 109}, {"startLine": 117, "kind": "comment", "endLine": 118}, {"startLine": 125, "endLine": 127}, {"startLine": 131, "endLine": 145}, {"startLine": 134, "endLine": 137}, {"startLine": 147, "kind": "comment", "endLine": 149}, {"startLine": 151, "endLine": 175}, {"startLine": 155, "endLine": 164}, {"startLine": 177, "endLine": 179}, {"startLine": 181, "endLine": 183}, {"startLine": 185, "kind": "comment", "endLine": 187}, {"startLine": 189, "endLine": 191}, {"startLine": 192, "endLine": 205}, {"startLine": 193, "endLine": 203}, {"startLine": 193, "endLine": 202}, {"startLine": 194, "endLine": 201}, {"startLine": 195, "endLine": 197}, {"startLine": 208, "endLine": 210}, {"startLine": 211, "endLine": 219}, {"startLine": 212, "endLine": 217}, {"startLine": 212, "endLine": 216}, {"startLine": 213, "endLine": 214}, {"startLine": 221, "endLine": 223}, {"startLine": 227, "endLine": 229}, {"startLine": 232, "endLine": 238}, {"startLine": 233, "endLine": 235}, {"startLine": 240, "endLine": 249}, {"startLine": 251, "endLine": 392}, {"startLine": 252, "endLine": 255}, {"startLine": 256, "endLine": 272}, {"startLine": 260, "endLine": 266}, {"startLine": 274, "endLine": 276}, {"startLine": 277, "endLine": 310}, {"startLine": 279, "endLine": 295}, {"startLine": 285, "endLine": 287}, {"startLine": 290, "endLine": 293}, {"startLine": 312, "endLine": 325}, {"startLine": 313, "endLine": 324}, {"startLine": 314, "endLine": 319}, {"startLine": 320, "endLine": 323}, {"startLine": 327, "endLine": 341}, {"startLine": 343, "endLine": 358}, {"startLine": 344, "endLine": 356}, {"startLine": 345, "endLine": 353}, {"startLine": 360, "endLine": 391}, {"startLine": 361, "endLine": 390}, {"startLine": 362, "endLine": 389}, {"startLine": 364, "endLine": 371}, {"startLine": 365, "endLine": 367}, {"startLine": 373, "endLine": 388}, {"startLine": 374, "endLine": 376}, {"startLine": 379, "endLine": 386}, {"startLine": 381, "endLine": 383}, {"startLine": 384, "endLine": 386}]}, "request": {"id": 2, "jsonrpc": "2.0", "method": "textDocument/foldingRange", "params": {"textDocument": {"uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs"}}}}]
-Sun Oct 18 21:15:36 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "range": {"end": {"character": 15, "line": 355}, "start": {"character": 12, "line": 355}}, "code": "unreachable_patterns", "message": "unreachable pattern\n`#[warn(unreachable_patterns)]` on by default", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1}}}]
-Sun Oct 18 21:15:36 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "tags": [1], "range": {"end": {"character": 28, "line": 618}, "start": {"character": 24, "line": 618}}, "code": "unused_variables", "message": "unused variable: `view`\n`#[warn(unused_variables)]` on by default", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-view/src/commands.rs"}}}]
-Sun Oct 18 21:15:36 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "range": {"end": {"character": 15, "line": 355}, "start": {"character": 12, "line": 355}}, "code": "unreachable_patterns", "message": "unreachable pattern\n`#[warn(unreachable_patterns)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 21, "line": 55}, "start": {"character": 13, "line": 55}}, "code": "unused_variables", "message": "unused variable: `incoming`\n`#[warn(unused_variables)]` on by default", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1}}}]
-Sun Oct 18 21:15:36 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "range": {"end": {"character": 15, "line": 355}, "start": {"character": 12, "line": 355}}, "code": "unreachable_patterns", "message": "unreachable pattern\n`#[warn(unreachable_patterns)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 21, "line": 55}, "start": {"character": 13, "line": 55}}, "code": "unused_variables", "message": "unused variable: `incoming`\n`#[warn(unused_variables)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 18, "line": 30}, "start": {"character": 4, "line": 30}}, "code": "dead_code", "message": "field is never read: `process`\n`#[warn(dead_code)]` on by default", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1}}}]
-Sun Oct 18 21:15:36 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "range": {"end": {"character": 15, "line": 355}, "start": {"character": 12, "line": 355}}, "code": "unreachable_patterns", "message": "unreachable pattern\n`#[warn(unreachable_patterns)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 21, "line": 55}, "start": {"character": 13, "line": 55}}, "code": "unused_variables", "message": "unused variable: `incoming`\n`#[warn(unused_variables)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 18, "line": 30}, "start": {"character": 4, "line": 30}}, "code": "dead_code", "message": "field is never read: `process`\n`#[warn(dead_code)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 34, "line": 31}, "start": {"character": 4, "line": 31}}, "code": "dead_code", "message": "field is never read: `stderr`", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1}}}]
-Sun Oct 18 21:15:36 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "range": {"end": {"character": 15, "line": 355}, "start": {"character": 12, "line": 355}}, "code": "unreachable_patterns", "message": "unreachable pattern\n`#[warn(unreachable_patterns)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 21, "line": 55}, "start": {"character": 13, "line": 55}}, "code": "unused_variables", "message": "unused variable: `incoming`\n`#[warn(unused_variables)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 18, "line": 30}, "start": {"character": 4, "line": 30}}, "code": "dead_code", "message": "field is never read: `process`\n`#[warn(dead_code)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 34, "line": 31}, "start": {"character": 4, "line": 31}}, "code": "dead_code", "message": "field is never read: `stderr`", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 29, "line": 241}, "start": {"character": 4, "line": 241}}, "code": "dead_code", "message": "field is never read: `incoming`", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1}}}]
-Sun Oct 18 21:15:39 2020:["lsp#register_server", "server registered", "typescript-language-server"]
-Sun Oct 18 21:15:39 2020:["lsp#register_server", "server registered", "elixir-ls"]
-Sun Oct 18 21:15:39 2020:["lsp#register_server", "server registered", "vue-language-server"]
-Sun Oct 18 21:15:39 2020:["lsp#register_server", "server registered", "rust-analyzer"]
-Sun Oct 18 21:15:39 2020:["s:on_text_document_did_open()", 1, "vim", "/Users/speed/src/helix/helix-lsp", "file:///Users/speed/.vimrc"]
-Sun Oct 18 21:15:40 2020:["s:on_text_document_did_change()", 1]
-Sun Oct 18 21:15:40 2020:["s:send_didchange_queue() will be triggered"]
-Sun Oct 18 21:15:40 2020:["s:on_text_document_did_change()", 1]
-Sun Oct 18 21:15:41 2020:["s:on_text_document_did_save()", 1]
-Sun Oct 18 21:15:41 2020:["s:on_text_document_did_close()", 1]
-Sun Oct 18 21:15:55 2020:["<---", 7, "rust-analyzer", {"response": {"method": "textDocument/publishDiagnostics", "jsonrpc": "2.0", "params": {"diagnostics": [{"source": "rustc", "range": {"end": {"character": 15, "line": 355}, "start": {"character": 12, "line": 355}}, "code": "unreachable_patterns", "message": "unreachable pattern\n`#[warn(unreachable_patterns)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 21, "line": 55}, "start": {"character": 13, "line": 55}}, "code": "unused_variables", "message": "unused variable: `incoming`\n`#[warn(unused_variables)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 18, "line": 30}, "start": {"character": 4, "line": 30}}, "code": "dead_code", "message": "field is never read: `process`\n`#[warn(dead_code)]` on by default", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 34, "line": 31}, "start": {"character": 4, "line": 31}}, "code": "dead_code", "message": "field is never read: `stderr`", "severity": 2}, {"source": "rustc", "tags": [1], "range": {"end": {"character": 29, "line": 241}, "start": {"character": 4, "line": 241}}, "code": "dead_code", "message": "field is never read: `incoming`", "severity": 2}], "uri": "file:///Users/speed/src/helix/helix-lsp/src/lib.rs", "version": 1}}}]
-Sun Oct 18 21:15:57 2020:["s:on_text_document_did_close()", 1]
-Sun Oct 18 21:15:57 2020:["s:on_exit", 7, "rust-analyzer", "exited", 143]
diff --git a/helix-lsp/src/transport.rs b/helix-lsp/src/transport.rs
index b30a8a6e..4ab3d5ec 100644
--- a/helix-lsp/src/transport.rs
+++ b/helix-lsp/src/transport.rs
@@ -1,5 +1,7 @@
 use std::collections::HashMap;
 
+use log::debug;
+
 use crate::{Error, Message, Notification};
 
 type Result<T> = core::result::Result<T, Error>;
@@ -114,7 +116,7 @@ impl Transport {
     }
 
     pub async fn send(&mut self, request: String) -> anyhow::Result<()> {
-        // println!("-> {}", request);
+        debug!("-> {}", request);
 
         // send the headers
         self.writer
@@ -135,11 +137,11 @@ impl Transport {
             Message::Notification(jsonrpc::Notification { method, params, .. }) => {
                 let notification = Notification::parse(&method, params);
 
-                // println!("<- {} {:?}", method, notification);
+                debug!("<- {} {:?}", method, notification);
                 self.incoming.send(notification).await?;
             }
-            Message::Call(_call) => {
-                // println!("<- {:?}", call);
+            Message::Call(call) => {
+                debug!("<- {:?}", call);
                 // dispatch
             }
         };
@@ -149,7 +151,7 @@ impl Transport {
     pub async fn recv_response(&mut self, output: jsonrpc::Output) -> anyhow::Result<()> {
         match output {
             jsonrpc::Output::Success(jsonrpc::Success { id, result, .. }) => {
-                // println!("<- {}", result);
+                debug!("<- {}", result);
 
                 let tx = self
                     .pending_requests
diff --git a/helix-term/Cargo.toml b/helix-term/Cargo.toml
index db1edee9..c1560ee7 100644
--- a/helix-term/Cargo.toml
+++ b/helix-term/Cargo.toml
@@ -19,10 +19,15 @@ helix-lsp = { path = "../helix-lsp"}
 anyhow = "1"
 
 smol = "1"
-num_cpus = "1.13"
+num_cpus = "1"
 # tui = { version = "0.12", default-features = false, features = ["crossterm"] }
 tui = { git = "https://github.com/fdehau/tui-rs", default-features = false, features = ["crossterm"] }
 crossterm = { version = "0.18", features = ["event-stream"] }
 clap = { version = "3.0.0-beta.2 ", default-features = false, features = ["std", "cargo"] }
 
 futures-util = "0.3"
+
+# Logging
+fern = "0.6"
+chrono = "0.4"
+log = "0.4"
diff --git a/helix-term/src/main.rs b/helix-term/src/main.rs
index de3a0175..f91c1c8f 100644
--- a/helix-term/src/main.rs
+++ b/helix-term/src/main.rs
@@ -11,6 +11,39 @@ use anyhow::Error;
 
 static EX: smol::Executor = smol::Executor::new();
 
+fn setup_logging(verbosity: u64) -> Result<(), fern::InitError> {
+    let mut base_config = fern::Dispatch::new();
+
+    // Let's say we depend on something which whose "info" level messages are too
+    // verbose to include in end-user output. If we don't need them,
+    // let's not include them.
+    // .level_for("overly-verbose-target", log::LevelFilter::Warn)
+
+    base_config = match verbosity {
+        0 => base_config.level(log::LevelFilter::Warn),
+        1 => base_config.level(log::LevelFilter::Info),
+        2 => base_config.level(log::LevelFilter::Debug),
+        _3_or_more => base_config.level(log::LevelFilter::Trace),
+    };
+
+    // Separate file config so we can include year, month and day in file logs
+    let file_config = fern::Dispatch::new()
+        .format(|out, message, record| {
+            out.finish(format_args!(
+                "{} {} [{}] {}",
+                chrono::Local::now().format("%Y-%m-%dT%H:%M:%S%.3f"),
+                record.target(),
+                record.level(),
+                message
+            ))
+        })
+        .chain(fern::log_file("helix.log")?);
+
+    base_config.chain(file_config).apply()?;
+
+    Ok(())
+}
+
 fn main() -> Result<(), Error> {
     let args = clap::app_from_crate!()
         .arg(
@@ -20,8 +53,19 @@ fn main() -> Result<(), Error> {
                 .multiple(true)
                 .index(1),
         )
+        .arg(
+            Arg::new("verbose")
+                .about("Increases logging verbosity each use for up to 3 times")
+                .short('v')
+                .takes_value(false)
+                .multiple_occurrences(true),
+        )
         .get_matches();
 
+    let verbosity: u64 = args.occurrences_of("verbose");
+
+    setup_logging(verbosity).expect("failed to initialize logging.");
+
     for _ in 0..num_cpus::get() {
         std::thread::spawn(move || smol::block_on(EX.run(smol::future::pending::<()>())));
     }

From cc6bdf8f66889087223d9a8491479ceecc09a663 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Fri, 23 Oct 2020 18:48:03 +0900
Subject: [PATCH 18/23] Text change generation, RPC call handling.

---
 helix-core/src/lib.rs         |   2 +-
 helix-core/src/transaction.rs |   9 ++-
 helix-lsp/src/client.rs       | 137 +++++++++++++++++++++++++++++++---
 helix-lsp/src/lib.rs          |  25 +++----
 helix-lsp/src/transport.rs    |  39 ++++++----
 helix-term/src/application.rs |  79 ++++++++++++--------
 helix-view/src/keymap.rs      |   3 +
 7 files changed, 221 insertions(+), 73 deletions(-)

diff --git a/helix-core/src/lib.rs b/helix-core/src/lib.rs
index 8458c36f..ddf1439c 100644
--- a/helix-core/src/lib.rs
+++ b/helix-core/src/lib.rs
@@ -27,4 +27,4 @@ pub use diagnostic::Diagnostic;
 pub use history::History;
 pub use state::State;
 
-pub use transaction::{Assoc, Change, ChangeSet, Transaction};
+pub use transaction::{Assoc, Change, ChangeSet, Operation, Transaction};
diff --git a/helix-core/src/transaction.rs b/helix-core/src/transaction.rs
index 9bd8c615..f1cb2ca1 100644
--- a/helix-core/src/transaction.rs
+++ b/helix-core/src/transaction.rs
@@ -5,8 +5,9 @@ use std::convert::TryFrom;
 /// (from, to, replacement)
 pub type Change = (usize, usize, Option<Tendril>);
 
+// TODO: pub(crate)
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub(crate) enum Operation {
+pub enum Operation {
     /// Move cursor by n characters.
     Retain(usize),
     /// Delete n characters.
@@ -40,6 +41,12 @@ impl ChangeSet {
     }
 
     // TODO: from iter
+    //
+
+    #[doc(hidden)] // used by lsp to convert to LSP changes
+    pub fn changes(&self) -> &[Operation] {
+        &self.changes
+    }
 
     #[must_use]
     fn len_after(&self) -> usize {
diff --git a/helix-lsp/src/client.rs b/helix-lsp/src/client.rs
index 56413768..3c2c1ce0 100644
--- a/helix-lsp/src/client.rs
+++ b/helix-lsp/src/client.rs
@@ -1,11 +1,11 @@
 use crate::{
     transport::{Payload, Transport},
-    Error, Notification,
+    Call, Error,
 };
 
 type Result<T> = core::result::Result<T, Error>;
 
-use helix_core::{State, Transaction};
+use helix_core::{ChangeSet, Transaction};
 use helix_view::Document;
 
 // use std::collections::HashMap;
@@ -27,7 +27,7 @@ pub struct Client {
     stderr: BufReader<ChildStderr>,
 
     outgoing: Sender<Payload>,
-    pub incoming: Receiver<Notification>,
+    pub incoming: Receiver<Call>,
 
     pub request_counter: u64,
 
@@ -87,6 +87,7 @@ impl Client {
         Ok(params)
     }
 
+    /// Execute a RPC request on the language server.
     pub async fn request<R: lsp::request::Request>(
         &mut self,
         params: R::Params,
@@ -126,6 +127,7 @@ impl Client {
         Ok(response)
     }
 
+    /// Send a RPC notification to the language server.
     pub async fn notify<R: lsp::notification::Notification>(
         &mut self,
         params: R::Params,
@@ -149,6 +151,35 @@ impl Client {
         Ok(())
     }
 
+    /// Reply to a language server RPC call.
+    pub async fn reply(
+        &mut self,
+        id: jsonrpc::Id,
+        result: core::result::Result<Value, jsonrpc::Error>,
+    ) -> Result<()> {
+        use jsonrpc::{Failure, Output, Success, Version};
+
+        let output = match result {
+            Ok(result) => Output::Success(Success {
+                jsonrpc: Some(Version::V2),
+                id,
+                result,
+            }),
+            Err(error) => Output::Failure(Failure {
+                jsonrpc: Some(Version::V2),
+                id,
+                error,
+            }),
+        };
+
+        self.outgoing
+            .send(Payload::Response(output))
+            .await
+            .map_err(|e| Error::Other(e.into()))?;
+
+        Ok(())
+    }
+
     // -------------------------------------------------------------------------------------------
     // General messages
     // -------------------------------------------------------------------------------------------
@@ -163,7 +194,9 @@ impl Client {
             // root_uri: Some(lsp_types::Url::parse("file://localhost/")?),
             root_uri: None, // set to project root in the future
             initialization_options: None,
-            capabilities: lsp::ClientCapabilities::default(),
+            capabilities: lsp::ClientCapabilities {
+                ..Default::default()
+            },
             trace: None,
             workspace_folders: None,
             client_info: None,
@@ -203,23 +236,107 @@ impl Client {
         .await
     }
 
+    fn to_changes(changeset: &ChangeSet) -> Vec<lsp::TextDocumentContentChangeEvent> {
+        let mut iter = changeset.changes().iter().peekable();
+        let mut old_pos = 0;
+
+        let mut changes = Vec::new();
+
+        use crate::util::pos_to_lsp_pos;
+        use helix_core::Operation::*;
+
+        // TEMP
+        let rope = helix_core::Rope::from("");
+        let old_text = rope.slice(..);
+
+        while let Some(change) = iter.next() {
+            let len = match change {
+                Delete(i) | Retain(i) => *i,
+                Insert(_) => 0,
+            };
+            let old_end = old_pos + len;
+
+            match change {
+                Retain(_) => {}
+                Delete(_) => {
+                    let start = pos_to_lsp_pos(&old_text, old_pos);
+                    let end = pos_to_lsp_pos(&old_text, old_end);
+
+                    // a subsequent ins means a replace, consume it
+                    if let Some(Insert(s)) = iter.peek() {
+                        iter.next();
+
+                        // replacement
+                        changes.push(lsp::TextDocumentContentChangeEvent {
+                            range: Some(lsp::Range::new(start, end)),
+                            text: s.into(),
+                            range_length: None,
+                        });
+                    } else {
+                        // deletion
+                        changes.push(lsp::TextDocumentContentChangeEvent {
+                            range: Some(lsp::Range::new(start, end)),
+                            text: "".to_string(),
+                            range_length: None,
+                        });
+                    };
+                }
+                Insert(s) => {
+                    let start = pos_to_lsp_pos(&old_text, old_pos);
+
+                    // insert
+                    changes.push(lsp::TextDocumentContentChangeEvent {
+                        range: Some(lsp::Range::new(start, start)),
+                        text: s.into(),
+                        range_length: None,
+                    });
+                }
+            }
+            old_pos = old_end;
+        }
+
+        changes
+    }
+
     // TODO: trigger any time history.commit_revision happens
     pub async fn text_document_did_change(
         &mut self,
         doc: &Document,
         transaction: &Transaction,
     ) -> Result<()> {
+        // figure out what kind of sync the server supports
+
+        let capabilities = self.capabilities.as_ref().unwrap(); // TODO: needs post init
+
+        let sync_capabilities = match capabilities.text_document_sync {
+            Some(lsp::TextDocumentSyncCapability::Kind(kind)) => kind,
+            Some(lsp::TextDocumentSyncCapability::Options(lsp::TextDocumentSyncOptions {
+                change: Some(kind),
+                ..
+            })) => kind,
+            // None | SyncOptions { changes: None }
+            _ => return Ok(()),
+        };
+
+        let changes = match sync_capabilities {
+            lsp::TextDocumentSyncKind::Full => {
+                vec![lsp::TextDocumentContentChangeEvent {
+                    // range = None -> whole document
+                    range: None,        //Some(Range)
+                    range_length: None, // u64 apparently deprecated
+                    text: "".to_string(),
+                }] // TODO: probably need old_state here too?
+            }
+            lsp::TextDocumentSyncKind::Incremental => Self::to_changes(transaction.changes()),
+            lsp::TextDocumentSyncKind::None => return Ok(()),
+        };
+
         self.notify::<lsp::notification::DidChangeTextDocument>(lsp::DidChangeTextDocumentParams {
             text_document: lsp::VersionedTextDocumentIdentifier::new(
                 lsp::Url::from_file_path(doc.path().unwrap()).unwrap(),
                 doc.version,
             ),
-            content_changes: vec![lsp::TextDocumentContentChangeEvent {
-                // range = None -> whole document
-                range: None,        //Some(Range)
-                range_length: None, // u64 apparently deprecated
-                text: "".to_string(),
-            }], // TODO: probably need old_state here too?
+            content_changes: changes,
         })
         .await
     }
diff --git a/helix-lsp/src/lib.rs b/helix-lsp/src/lib.rs
index c37222f1..1ee8199f 100644
--- a/helix-lsp/src/lib.rs
+++ b/helix-lsp/src/lib.rs
@@ -1,13 +1,12 @@
 mod client;
 mod transport;
 
-use jsonrpc_core as jsonrpc;
-use lsp_types as lsp;
+pub use jsonrpc_core as jsonrpc;
+pub use lsp_types as lsp;
 
 pub use client::Client;
 pub use lsp::{Position, Url};
 
-use serde::{Deserialize, Serialize};
 use thiserror::Error;
 
 #[derive(Error, Debug)]
@@ -30,19 +29,13 @@ pub mod util {
         let line_start = doc.char_to_utf16_cu(line);
         doc.utf16_cu_to_char(pos.character as usize + line_start)
     }
-}
+    pub fn pos_to_lsp_pos(doc: &helix_core::RopeSlice, pos: usize) -> lsp::Position {
+        let line = doc.char_to_line(pos);
+        let line_start = doc.char_to_utf16_cu(line);
+        let col = doc.char_to_utf16_cu(pos) - line_start;
 
-/// A type representing all possible values sent from the server to the client.
-#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
-#[serde(deny_unknown_fields)]
-#[serde(untagged)]
-enum Message {
-    /// A regular JSON-RPC request output (single response).
-    Output(jsonrpc::Output),
-    /// A notification.
-    Notification(jsonrpc::Notification),
-    /// A JSON-RPC request
-    Call(jsonrpc::Call),
+        lsp::Position::new(line as u64, col as u64)
+    }
 }
 
 #[derive(Debug, PartialEq, Clone)]
@@ -67,3 +60,5 @@ impl Notification {
         }
     }
 }
+
+pub use jsonrpc::Call;
diff --git a/helix-lsp/src/transport.rs b/helix-lsp/src/transport.rs
index 4ab3d5ec..4c349a13 100644
--- a/helix-lsp/src/transport.rs
+++ b/helix-lsp/src/transport.rs
@@ -2,7 +2,7 @@ use std::collections::HashMap;
 
 use log::debug;
 
-use crate::{Error, Message, Notification};
+use crate::{Error, Notification};
 
 type Result<T> = core::result::Result<T, Error>;
 
@@ -24,10 +24,23 @@ pub(crate) enum Payload {
         value: jsonrpc::MethodCall,
     },
     Notification(jsonrpc::Notification),
+    Response(jsonrpc::Output),
+}
+
+use serde::{Deserialize, Serialize};
+/// A type representing all possible values sent from the server to the client.
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(deny_unknown_fields)]
+#[serde(untagged)]
+enum Message {
+    /// A regular JSON-RPC request output (single response).
+    Output(jsonrpc::Output),
+    /// A JSON-RPC request or notification.
+    Call(jsonrpc::Call),
 }
 
 pub(crate) struct Transport {
-    incoming: Sender<Notification>, // TODO Notification | Call
+    incoming: Sender<jsonrpc::Call>,
     outgoing: Receiver<Payload>,
 
     pending_requests: HashMap<jsonrpc::Id, Sender<Result<Value>>>,
@@ -42,7 +55,7 @@ impl Transport {
         ex: &Executor,
         reader: BufReader<ChildStdout>,
         writer: BufWriter<ChildStdin>,
-    ) -> (Receiver<Notification>, Sender<Payload>) {
+    ) -> (Receiver<jsonrpc::Call>, Sender<Payload>) {
         let (incoming, rx) = smol::channel::unbounded();
         let (tx, outgoing) = smol::channel::unbounded();
 
@@ -112,6 +125,10 @@ impl Transport {
                 let json = serde_json::to_string(&value)?;
                 self.send(json).await
             }
+            Payload::Response(error) => {
+                let json = serde_json::to_string(&error)?;
+                self.send(json).await
+            }
         }
     }
 
@@ -131,24 +148,18 @@ impl Transport {
         Ok(())
     }
 
-    pub async fn recv_msg(&mut self, msg: Message) -> anyhow::Result<()> {
+    async fn recv_msg(&mut self, msg: Message) -> anyhow::Result<()> {
         match msg {
             Message::Output(output) => self.recv_response(output).await?,
-            Message::Notification(jsonrpc::Notification { method, params, .. }) => {
-                let notification = Notification::parse(&method, params);
-
-                debug!("<- {} {:?}", method, notification);
-                self.incoming.send(notification).await?;
-            }
             Message::Call(call) => {
-                debug!("<- {:?}", call);
-                // dispatch
+                self.incoming.send(call).await?;
+                // let notification = Notification::parse(&method, params);
             }
         };
         Ok(())
     }
 
-    pub async fn recv_response(&mut self, output: jsonrpc::Output) -> anyhow::Result<()> {
+    async fn recv_response(&mut self, output: jsonrpc::Output) -> anyhow::Result<()> {
         match output {
             jsonrpc::Output::Success(jsonrpc::Success { id, result, .. }) => {
                 debug!("<- {}", result);
@@ -191,6 +202,8 @@ impl Transport {
                     }
                     let msg = msg.unwrap();
 
+                    debug!("<- {:?}", msg);
+
                     self.recv_msg(msg).await.unwrap();
                 }
             }
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index b9594b7e..802dd399 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -433,8 +433,8 @@ impl<'a> Application<'a> {
                 event = reader.next().fuse() => {
                     self.handle_terminal_events(event).await
                 }
-                notification = self.lsp.incoming.next().fuse() => {
-                    self.handle_lsp_notification(notification).await
+                call = self.lsp.incoming.next().fuse() => {
+                    self.handle_lsp_message(call).await
                 }
             }
         }
@@ -566,43 +566,56 @@ impl<'a> Application<'a> {
         };
     }
 
-    pub async fn handle_lsp_notification(&mut self, notification: Option<helix_lsp::Notification>) {
-        use helix_lsp::Notification;
-        match notification {
-            Some(Notification::PublishDiagnostics(params)) => {
-                let path = Some(params.uri.to_file_path().unwrap());
-                let view = self
-                    .editor
-                    .views
-                    .iter_mut()
-                    .find(|view| view.doc.path == path);
+    pub async fn handle_lsp_message(&mut self, call: Option<helix_lsp::Call>) {
+        use helix_lsp::{Call, Notification};
+        match call {
+            Some(Call::Notification(helix_lsp::jsonrpc::Notification {
+                method, params, ..
+            })) => {
+                let notification = Notification::parse(&method, params);
+                match notification {
+                    Notification::PublishDiagnostics(params) => {
+                        let path = Some(params.uri.to_file_path().unwrap());
+                        let view = self
+                            .editor
+                            .views
+                            .iter_mut()
+                            .find(|view| view.doc.path == path);
 
-                if let Some(view) = view {
-                    let doc = view.doc.text().slice(..);
-                    let diagnostics = params
-                        .diagnostics
-                        .into_iter()
-                        .map(|diagnostic| {
-                            use helix_lsp::util::lsp_pos_to_pos;
-                            let start = lsp_pos_to_pos(&doc, diagnostic.range.start);
-                            let end = lsp_pos_to_pos(&doc, diagnostic.range.end);
+                        if let Some(view) = view {
+                            let doc = view.doc.text().slice(..);
+                            let diagnostics = params
+                                .diagnostics
+                                .into_iter()
+                                .map(|diagnostic| {
+                                    use helix_lsp::util::lsp_pos_to_pos;
+                                    let start = lsp_pos_to_pos(&doc, diagnostic.range.start);
+                                    let end = lsp_pos_to_pos(&doc, diagnostic.range.end);
 
-                            helix_core::Diagnostic {
-                                range: (start, end),
-                                line: diagnostic.range.start.line as usize,
-                                message: diagnostic.message,
-                                // severity
-                                // code
-                                // source
-                            }
-                        })
-                        .collect();
+                                    helix_core::Diagnostic {
+                                        range: (start, end),
+                                        line: diagnostic.range.start.line as usize,
+                                        message: diagnostic.message,
+                                        // severity
+                                        // code
+                                        // source
+                                    }
+                                })
+                                .collect();
 
-                    view.doc.diagnostics = diagnostics;
+                            view.doc.diagnostics = diagnostics;
 
-                    self.render();
+                            self.render();
+                        }
+                    }
+                    _ => unreachable!(),
                 }
             }
+            Some(Call::MethodCall(call)) => {
+                // TODO: need to make Result<Value, Error>
+
+                unimplemented!("{:?}", call)
+            }
             _ => unreachable!(),
         }
     }
diff --git a/helix-view/src/keymap.rs b/helix-view/src/keymap.rs
index aaba34a6..c815911e 100644
--- a/helix-view/src/keymap.rs
+++ b/helix-view/src/keymap.rs
@@ -82,6 +82,9 @@ use std::collections::HashMap;
 //          = = align?
 //          + =
 //      }
+//
+//      gd = goto definition
+//      gr = goto reference
 // }
 
 #[cfg(feature = "term")]

From ae8a9e5bac2cb4683015604bb5a431781717c991 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Thu, 29 Oct 2020 14:06:33 +0900
Subject: [PATCH 19/23] lsp: Make base request methods take &self instead of
 &mut self.

---
 Cargo.lock                    | 84 +++++++++++++++++++----------------
 helix-lsp/Cargo.toml          |  2 +-
 helix-lsp/src/client.rs       | 28 +++++-------
 helix-term/src/application.rs | 23 +++++-----
 helix-view/src/commands.rs    |  2 +
 5 files changed, 72 insertions(+), 67 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index bc3da508..28fc503c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -29,9 +29,9 @@ checksum = "a4c527152e37cf757a3f78aae5a06fbeefdb07ccc535c980a3208ee3060dd544"
 
 [[package]]
 name = "arrayvec"
-version = "0.5.1"
+version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cff77d8686867eceff3105329d4698d96c2391c176d5d03adc90c7389162b5b8"
+checksum = "23b62fc65de8e4e7f52534fb52b0f3ed04746ae267519eef2a83941e8085068b"
 
 [[package]]
 name = "async-channel"
@@ -118,7 +118,7 @@ checksum = "4c8cea09c1fb10a317d1b5af8024eeba256d6554763e85ecd90ff8df31c7bbda"
 dependencies = [
  "async-io",
  "blocking",
- "cfg-if",
+ "cfg-if 0.1.10",
  "event-listener",
  "futures-lite",
  "once_cell",
@@ -208,6 +208,12 @@ version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
 [[package]]
 name = "chrono"
 version = "0.4.19"
@@ -267,15 +273,15 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c3c7c73a2d1e9fc0886a08b93e98eb643461230d5f1925e4036204d5f2e261a8"
 dependencies = [
  "autocfg",
- "cfg-if",
+ "cfg-if 0.1.10",
  "lazy_static",
 ]
 
 [[package]]
 name = "crossterm"
-version = "0.18.0"
+version = "0.18.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c2fcdc3c9cf8ee446222e8ee8691a6d21b563b8fe1a64b1873080db7b5b23cf0"
+checksum = "cef9149b29071d44c9fb98fd9c27fcf74405bbdb761889ad6a03f36be93b0b15"
 dependencies = [
  "bitflags",
  "crossterm_winapi",
@@ -290,9 +296,9 @@ dependencies = [
 
 [[package]]
 name = "crossterm_winapi"
-version = "0.6.1"
+version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "057b7146d02fb50175fd7dbe5158f6097f33d02831f43b4ee8ae4ddf67b68f5c"
+checksum = "c2265c3f8e080075d9b6417aa72293fc71662f34b4af2612d8d1b074d29510db"
 dependencies = [
  "winapi",
 ]
@@ -303,7 +309,7 @@ version = "2.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "13aea89a5c93364a98e9b37b2fa237effbb694d5cfe01c5b70941f7eb087d5e3"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "dirs-sys",
 ]
 
@@ -360,15 +366,15 @@ checksum = "4c7e4c2612746b0df8fed4ce0c69156021b704c9aefa360311c04e6e9e002eed"
 
 [[package]]
 name = "futures-core"
-version = "0.3.6"
+version = "0.3.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d674eaa0056896d5ada519900dbf97ead2e46a7b6621e8160d79e2f2e1e2784b"
+checksum = "18eaa56102984bed2c88ea39026cff3ce3b4c7f508ca970cedf2450ea10d4e46"
 
 [[package]]
 name = "futures-io"
-version = "0.3.6"
+version = "0.3.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5fc94b64bb39543b4e432f1790b6bf18e3ee3b74653c5449f63310e9a74b123c"
+checksum = "6e1798854a4727ff944a7b12aa999f58ce7aa81db80d2dfaaf2ba06f065ddd2b"
 
 [[package]]
 name = "futures-lite"
@@ -387,9 +393,9 @@ dependencies = [
 
 [[package]]
 name = "futures-macro"
-version = "0.3.6"
+version = "0.3.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f57ed14da4603b2554682e9f2ff3c65d7567b53188db96cb71538217fc64581b"
+checksum = "e36fccf3fc58563b4a14d265027c627c3b665d7fed489427e88e7cc929559efe"
 dependencies = [
  "proc-macro-hack",
  "proc-macro2",
@@ -399,18 +405,18 @@ dependencies = [
 
 [[package]]
 name = "futures-task"
-version = "0.3.6"
+version = "0.3.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4dd26820a9f3637f1302da8bceba3ff33adbe53464b54ca24d4e2d4f1db30f94"
+checksum = "96d502af37186c4fef99453df03e374683f8a1eec9dcc1e66b3b82dc8278ce3c"
 dependencies = [
  "once_cell",
 ]
 
 [[package]]
 name = "futures-util"
-version = "0.3.6"
+version = "0.3.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8a894a0acddba51a2d49a6f4263b1e64b8c579ece8af50fa86503d52cd1eea34"
+checksum = "abcb44342f62e6f3e8ac427b8aa815f724fd705dfad060b18ac7866c15bb8e34"
 dependencies = [
  "futures-core",
  "futures-macro",
@@ -428,7 +434,7 @@ version = "0.1.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fc587bc0ec293155d5bfa6b9891ec18a1e330c234f896ea47fbada4cadbe47e6"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "libc",
  "wasi 0.9.0+wasi-snapshot-preview1",
 ]
@@ -553,11 +559,11 @@ dependencies = [
 
 [[package]]
 name = "instant"
-version = "0.1.7"
+version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "63312a18f7ea8760cdd0a7c5aac1a619752a246b833545e3e36d1f81f7cd9e66"
+checksum = "cb1fc4429a33e1f80d41dc9fea4d108a88bec1de8053878898ae448a0b52f613"
 dependencies = [
- "cfg-if",
+ "cfg-if 1.0.0",
 ]
 
 [[package]]
@@ -596,9 +602,9 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "libc"
-version = "0.2.79"
+version = "0.2.80"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2448f6066e80e3bfc792e9c98bf705b4b0fc6e8ef5b43e5889aff0eaa9c58743"
+checksum = "4d58d1b70b004888f764dfbf6a26a3b0342a1632d33968e4a179d8011c760614"
 
 [[package]]
 name = "lock_api"
@@ -615,14 +621,14 @@ version = "0.4.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4fabed175da42fed1fa0746b0ea71f412aa9d35e76e95e59b192c64b9dc2bf8b"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
 ]
 
 [[package]]
 name = "lsp-types"
-version = "0.82.0"
+version = "0.83.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db895abb8527cf59e3de893ab2acf52cf904faeb65e60ea6f373e11fe86464e8"
+checksum = "25e0bd4b95038f2c23bda332ba0ca684e8dda765db1f9bdb63dc4c3e01f3b456"
 dependencies = [
  "base64",
  "bitflags",
@@ -691,9 +697,9 @@ checksum = "e4a24736216ec316047a1fc4252e27dabb04218aa4a3f37c6e7ddbf1f9782b54"
 
 [[package]]
 name = "ntapi"
-version = "0.3.4"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a31937dea023539c72ddae0e3571deadc1414b300483fa7aaec176168cfa9d2"
+checksum = "3f6bb902e437b6d86e03cce10a7e2af662292c5dfef23b65899ea3ac9354ad44"
 dependencies = [
  "winapi",
 ]
@@ -762,7 +768,7 @@ version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c361aa727dd08437f2f1447be8b59a33b0edd15e0fcee698f935613d9efbca9b"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "cloudabi",
  "instant",
  "libc",
@@ -785,18 +791,18 @@ checksum = "d4fd5641d01c8f18a23da7b6fe29298ff4b55afcccdf78973b24cf3175fee32e"
 
 [[package]]
 name = "pin-project"
-version = "0.4.27"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2ffbc8e94b38ea3d2d8ba92aea2983b503cd75d0888d75b86bb37970b5698e15"
+checksum = "ee41d838744f60d959d7074e3afb6b35c7456d0f61cad38a24e35e6553f73841"
 dependencies = [
  "pin-project-internal",
 ]
 
 [[package]]
 name = "pin-project-internal"
-version = "0.4.27"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "65ad2ae56b6abe3a1ee25f15ee605bacadb9a764edaba9c2bf4103800d4a1895"
+checksum = "81a4ffa594b66bff340084d4081df649a7dc049ac8d7fc458d8e628bfbbb2f86"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -821,7 +827,7 @@ version = "2.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a2a7bc6b2a29e632e45451c941832803a18cce6781db04de8a04696cdca8bde4"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "libc",
  "log",
  "wepoll-sys",
@@ -1034,7 +1040,7 @@ version = "0.3.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b1fa70dc5c8104ec096f4fe7ede7a221d35ae13dcd19ba1ad9a81d2cab9a1c44"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "libc",
  "redox_syscall",
  "winapi",
@@ -1042,9 +1048,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.46"
+version = "1.0.48"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ad5de3220ea04da322618ded2c42233d02baca219d6f160a3e9c87cda16c942"
+checksum = "cc371affeffc477f42a221a1e4297aedcea33d47d19b61455588bd9d8f6b19ac"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/helix-lsp/Cargo.toml b/helix-lsp/Cargo.toml
index ffd909a4..0c5d8b91 100644
--- a/helix-lsp/Cargo.toml
+++ b/helix-lsp/Cargo.toml
@@ -10,7 +10,7 @@ edition = "2018"
 helix-core = { path = "../helix-core" }
 helix-view = { path = "../helix-view" }
 
-lsp-types = { version = "0.82", features = ["proposed"] }
+lsp-types = { version = "0.83", features = ["proposed"] }
 smol = "1.2"
 url = "2"
 pathdiff = "0.2"
diff --git a/helix-lsp/src/client.rs b/helix-lsp/src/client.rs
index 3c2c1ce0..1583bfb8 100644
--- a/helix-lsp/src/client.rs
+++ b/helix-lsp/src/client.rs
@@ -9,6 +9,7 @@ use helix_core::{ChangeSet, Transaction};
 use helix_view::Document;
 
 // use std::collections::HashMap;
+use std::sync::atomic::{AtomicU64, Ordering};
 
 use jsonrpc_core as jsonrpc;
 use lsp_types as lsp;
@@ -29,7 +30,7 @@ pub struct Client {
     outgoing: Sender<Payload>,
     pub incoming: Receiver<Call>,
 
-    pub request_counter: u64,
+    pub request_counter: AtomicU64,
 
     capabilities: Option<lsp::ServerCapabilities>,
     // TODO: handle PublishDiagnostics Version
@@ -61,17 +62,16 @@ impl Client {
             outgoing,
             incoming,
 
-            request_counter: 0,
+            request_counter: AtomicU64::new(0),
 
             capabilities: None,
             // diagnostics: HashMap::new(),
         }
     }
 
-    fn next_request_id(&mut self) -> jsonrpc::Id {
-        let id = jsonrpc::Id::Num(self.request_counter);
-        self.request_counter += 1;
-        id
+    fn next_request_id(&self) -> jsonrpc::Id {
+        let id = self.request_counter.fetch_add(1, Ordering::Relaxed);
+        jsonrpc::Id::Num(id)
     }
 
     fn to_params(value: Value) -> Result<jsonrpc::Params> {
@@ -88,10 +88,7 @@ impl Client {
     }
 
     /// Execute a RPC request on the language server.
-    pub async fn request<R: lsp::request::Request>(
-        &mut self,
-        params: R::Params,
-    ) -> Result<R::Result>
+    pub async fn request<R: lsp::request::Request>(&self, params: R::Params) -> Result<R::Result>
     where
         R::Params: serde::Serialize,
         R::Result: core::fmt::Debug, // TODO: temporary
@@ -128,10 +125,7 @@ impl Client {
     }
 
     /// Send a RPC notification to the language server.
-    pub async fn notify<R: lsp::notification::Notification>(
-        &mut self,
-        params: R::Params,
-    ) -> Result<()>
+    pub async fn notify<R: lsp::notification::Notification>(&self, params: R::Params) -> Result<()>
     where
         R::Params: serde::Serialize,
     {
@@ -153,7 +147,7 @@ impl Client {
 
     /// Reply to a language server RPC call.
     pub async fn reply(
-        &mut self,
+        &self,
         id: jsonrpc::Id,
         result: core::result::Result<Value, jsonrpc::Error>,
     ) -> Result<()> {
@@ -212,11 +206,11 @@ impl Client {
         Ok(())
     }
 
-    pub async fn shutdown(&mut self) -> Result<()> {
+    pub async fn shutdown(&self) -> Result<()> {
         self.request::<lsp::request::Shutdown>(()).await
     }
 
-    pub async fn exit(&mut self) -> Result<()> {
+    pub async fn exit(&self) -> Result<()> {
         self.notify::<lsp::notification::Exit>(()).await
     }
 
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index 802dd399..a4a3cf09 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -8,6 +8,8 @@ use helix_view::{
     Document, Editor, Theme, View,
 };
 
+use log::{debug, info};
+
 use std::{
     borrow::Cow,
     io::{self, stdout, Stdout, Write},
@@ -46,7 +48,7 @@ pub struct Application<'a> {
 
     keymap: Keymaps,
     executor: &'a smol::Executor<'a>,
-    lsp: helix_lsp::Client,
+    language_server: helix_lsp::Client,
 }
 
 struct Renderer {
@@ -370,7 +372,7 @@ impl<'a> Application<'a> {
             editor.open(file, terminal.size)?;
         }
 
-        let lsp = helix_lsp::Client::start(&executor, "rust-analyzer", &[]);
+        let language_server = helix_lsp::Client::start(&executor, "rust-analyzer", &[]);
 
         let mut app = Self {
             editor,
@@ -381,7 +383,7 @@ impl<'a> Application<'a> {
             //
             keymap: keymap::default(),
             executor,
-            lsp,
+            language_server,
         };
 
         Ok(app)
@@ -415,11 +417,11 @@ impl<'a> Application<'a> {
         let mut reader = EventStream::new();
 
         // initialize lsp
-        let res = self.lsp.initialize().await;
-        let res = self
-            .lsp
+        self.language_server.initialize().await.unwrap();
+        self.language_server
             .text_document_did_open(&self.editor.view().unwrap().doc)
-            .await;
+            .await
+            .unwrap();
 
         self.render();
 
@@ -433,8 +435,8 @@ impl<'a> Application<'a> {
                 event = reader.next().fuse() => {
                     self.handle_terminal_events(event).await
                 }
-                call = self.lsp.incoming.next().fuse() => {
-                    self.handle_lsp_message(call).await
+                call = self.language_server.incoming.next().fuse() => {
+                    self.handle_language_server_message(call).await
                 }
             }
         }
@@ -566,7 +568,7 @@ impl<'a> Application<'a> {
         };
     }
 
-    pub async fn handle_lsp_message(&mut self, call: Option<helix_lsp::Call>) {
+    pub async fn handle_language_server_message(&mut self, call: Option<helix_lsp::Call>) {
         use helix_lsp::{Call, Notification};
         match call {
             Some(Call::Notification(helix_lsp::jsonrpc::Notification {
@@ -605,6 +607,7 @@ impl<'a> Application<'a> {
 
                             view.doc.diagnostics = diagnostics;
 
+                            // TODO: we want to process all the events in queue, then render. publishDiagnostic tends to send a whole bunch of events
                             self.render();
                         }
                     }
diff --git a/helix-view/src/commands.rs b/helix-view/src/commands.rs
index 52e09dd6..f2e62044 100644
--- a/helix-view/src/commands.rs
+++ b/helix-view/src/commands.rs
@@ -404,6 +404,8 @@ fn append_changes_to_history(view: &mut View) {
     let old_state = std::mem::replace(&mut view.doc.old_state, view.doc.state.clone());
     // TODO: take transaction by value?
     view.doc.history.commit_revision(&transaction, &old_state);
+
+    // TODO: notify LSP of changes
 }
 
 pub fn normal_mode(view: &mut View, _count: usize) {

From 8f0bcfe286d97dfff67bd924e11ca2b6ae1a63dc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Fri, 30 Oct 2020 14:09:59 +0900
Subject: [PATCH 20/23] Introduce a command context that carries the executor
 and other fields.

---
 helix-term/src/application.rs |  29 ++-
 helix-view/src/commands.rs    | 454 ++++++++++++++++++----------------
 2 files changed, 264 insertions(+), 219 deletions(-)

diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index a4a3cf09..cacfde56 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -476,13 +476,24 @@ impl<'a> Application<'a> {
                     match view.doc.mode() {
                         Mode::Insert => {
                             if let Some(command) = self.keymap[&Mode::Insert].get(&keys) {
-                                command(view, 1);
+                                let mut cx = helix_view::commands::Context {
+                                    view,
+                                    executor: self.executor,
+                                    count: 1,
+                                };
+
+                                command(&mut cx);
                             } else if let KeyEvent {
                                 code: KeyCode::Char(c),
                                 ..
                             } = event
                             {
-                                commands::insert::insert_char(view, c);
+                                let mut cx = helix_view::commands::Context {
+                                    view,
+                                    executor: self.executor,
+                                    count: 1,
+                                };
+                                commands::insert::insert_char(&mut cx, c);
                             }
                             view.ensure_cursor_in_view();
                         }
@@ -544,7 +555,12 @@ impl<'a> Application<'a> {
 
                             // HAXX: special casing for command mode
                             } else if let Some(command) = self.keymap[&Mode::Normal].get(&keys) {
-                                command(view, 1);
+                                let mut cx = helix_view::commands::Context {
+                                    view,
+                                    executor: self.executor,
+                                    count: 1,
+                                };
+                                command(&mut cx);
 
                                 // TODO: simplistic ensure cursor in view for now
                                 view.ensure_cursor_in_view();
@@ -552,7 +568,12 @@ impl<'a> Application<'a> {
                         }
                         mode => {
                             if let Some(command) = self.keymap[&mode].get(&keys) {
-                                command(view, 1);
+                                let mut cx = helix_view::commands::Context {
+                                    view,
+                                    executor: self.executor,
+                                    count: 1,
+                                };
+                                command(&mut cx);
 
                                 // TODO: simplistic ensure cursor in view for now
                                 view.ensure_cursor_in_view();
diff --git a/helix-view/src/commands.rs b/helix-view/src/commands.rs
index f2e62044..26c7a190 100644
--- a/helix-view/src/commands.rs
+++ b/helix-view/src/commands.rs
@@ -14,44 +14,54 @@ use crate::{
     view::{View, PADDING},
 };
 
+pub struct Context<'a, 'b> {
+    pub count: usize,
+    pub view: &'a mut View,
+    pub executor: &'a smol::Executor<'b>,
+}
+
 /// A command is a function that takes the current state and a count, and does a side-effect on the
 /// state (usually by creating and applying a transaction).
-pub type Command = fn(view: &mut View, count: usize);
+pub type Command = fn(cx: &mut Context);
 
-pub fn move_char_left(view: &mut View, count: usize) {
+pub fn move_char_left(cx: &mut Context) {
     let selection =
-        view.doc
+        cx.view
+            .doc
             .state
-            .move_selection(Direction::Backward, Granularity::Character, count);
-    view.doc.set_selection(selection);
+            .move_selection(Direction::Backward, Granularity::Character, cx.count);
+    cx.view.doc.set_selection(selection);
 }
 
-pub fn move_char_right(view: &mut View, count: usize) {
+pub fn move_char_right(cx: &mut Context) {
     let selection =
-        view.doc
+        cx.view
+            .doc
             .state
-            .move_selection(Direction::Forward, Granularity::Character, count);
-    view.doc.set_selection(selection);
+            .move_selection(Direction::Forward, Granularity::Character, cx.count);
+    cx.view.doc.set_selection(selection);
 }
 
-pub fn move_line_up(view: &mut View, count: usize) {
-    let selection = view
-        .doc
-        .state
-        .move_selection(Direction::Backward, Granularity::Line, count);
-    view.doc.set_selection(selection);
+pub fn move_line_up(cx: &mut Context) {
+    let selection =
+        cx.view
+            .doc
+            .state
+            .move_selection(Direction::Backward, Granularity::Line, cx.count);
+    cx.view.doc.set_selection(selection);
 }
 
-pub fn move_line_down(view: &mut View, count: usize) {
-    let selection = view
-        .doc
-        .state
-        .move_selection(Direction::Forward, Granularity::Line, count);
-    view.doc.set_selection(selection);
+pub fn move_line_down(cx: &mut Context) {
+    let selection =
+        cx.view
+            .doc
+            .state
+            .move_selection(Direction::Forward, Granularity::Line, cx.count);
+    cx.view.doc.set_selection(selection);
 }
 
-pub fn move_line_end(view: &mut View, _count: usize) {
-    let lines = selection_lines(&view.doc.state);
+pub fn move_line_end(cx: &mut Context) {
+    let lines = selection_lines(&cx.view.doc.state);
 
     let positions = lines
         .into_iter()
@@ -60,78 +70,78 @@ pub fn move_line_end(view: &mut View, _count: usize) {
 
             // Line end is pos at the start of next line - 1
             // subtract another 1 because the line ends with \n
-            view.doc.text().line_to_char(index + 1).saturating_sub(2)
+            cx.view.doc.text().line_to_char(index + 1).saturating_sub(2)
         })
         .map(|pos| Range::new(pos, pos));
 
     let selection = Selection::new(positions.collect(), 0);
 
-    view.doc.set_selection(selection);
+    cx.view.doc.set_selection(selection);
 }
 
-pub fn move_line_start(view: &mut View, _count: usize) {
-    let lines = selection_lines(&view.doc.state);
+pub fn move_line_start(cx: &mut Context) {
+    let lines = selection_lines(&cx.view.doc.state);
 
     let positions = lines
         .into_iter()
         .map(|index| {
             // adjust all positions to the start of the line.
-            view.doc.text().line_to_char(index)
+            cx.view.doc.text().line_to_char(index)
         })
         .map(|pos| Range::new(pos, pos));
 
     let selection = Selection::new(positions.collect(), 0);
 
-    view.doc.set_selection(selection);
+    cx.view.doc.set_selection(selection);
 }
 
-pub fn move_next_word_start(view: &mut View, count: usize) {
-    let pos = view.doc.state.move_pos(
-        view.doc.selection().cursor(),
+pub fn move_next_word_start(cx: &mut Context) {
+    let pos = cx.view.doc.state.move_pos(
+        cx.view.doc.selection().cursor(),
         Direction::Forward,
         Granularity::Word,
-        count,
+        cx.count,
     );
 
-    view.doc.set_selection(Selection::point(pos));
+    cx.view.doc.set_selection(Selection::point(pos));
 }
 
-pub fn move_prev_word_start(view: &mut View, count: usize) {
-    let pos = view.doc.state.move_pos(
-        view.doc.selection().cursor(),
+pub fn move_prev_word_start(cx: &mut Context) {
+    let pos = cx.view.doc.state.move_pos(
+        cx.view.doc.selection().cursor(),
         Direction::Backward,
         Granularity::Word,
-        count,
+        cx.count,
     );
 
-    view.doc.set_selection(Selection::point(pos));
+    cx.view.doc.set_selection(Selection::point(pos));
 }
 
-pub fn move_next_word_end(view: &mut View, count: usize) {
+pub fn move_next_word_end(cx: &mut Context) {
     let pos = State::move_next_word_end(
-        &view.doc.text().slice(..),
-        view.doc.selection().cursor(),
-        count,
+        &cx.view.doc.text().slice(..),
+        cx.view.doc.selection().cursor(),
+        cx.count,
     );
 
-    view.doc.set_selection(Selection::point(pos));
+    cx.view.doc.set_selection(Selection::point(pos));
 }
 
-pub fn move_file_start(view: &mut View, _count: usize) {
-    view.doc.set_selection(Selection::point(0));
+pub fn move_file_start(cx: &mut Context) {
+    cx.view.doc.set_selection(Selection::point(0));
 
-    view.doc.mode = Mode::Normal;
+    cx.view.doc.mode = Mode::Normal;
 }
 
-pub fn move_file_end(view: &mut View, _count: usize) {
-    let text = &view.doc.text();
+pub fn move_file_end(cx: &mut Context) {
+    let text = &cx.view.doc.text();
     let last_line = text.line_to_char(text.len_lines().saturating_sub(2));
-    view.doc.set_selection(Selection::point(last_line));
+    cx.view.doc.set_selection(Selection::point(last_line));
 
-    view.doc.mode = Mode::Normal;
+    cx.view.doc.mode = Mode::Normal;
 }
 
-pub fn check_cursor_in_view(view: &mut View) -> bool {
+pub fn check_cursor_in_view(view: &View) -> bool {
     let cursor = view.doc.selection().cursor();
     let line = view.doc.text().char_to_line(cursor);
     let document_end = view.first_line + view.size.1.saturating_sub(1) as usize;
@@ -142,172 +152,182 @@ pub fn check_cursor_in_view(view: &mut View) -> bool {
     true
 }
 
-pub fn page_up(view: &mut View, _count: usize) {
-    if view.first_line < PADDING {
+pub fn page_up(cx: &mut Context) {
+    if cx.view.first_line < PADDING {
         return;
     }
 
-    view.first_line = view.first_line.saturating_sub(view.size.1 as usize);
+    cx.view.first_line = cx.view.first_line.saturating_sub(cx.view.size.1 as usize);
 
-    if !check_cursor_in_view(view) {
-        let text = view.doc.text();
-        let pos = text.line_to_char(view.last_line().saturating_sub(PADDING));
-        view.doc.set_selection(Selection::point(pos));
+    if !check_cursor_in_view(cx.view) {
+        let text = cx.view.doc.text();
+        let pos = text.line_to_char(cx.view.last_line().saturating_sub(PADDING));
+        cx.view.doc.set_selection(Selection::point(pos));
     }
 }
 
-pub fn page_down(view: &mut View, _count: usize) {
-    view.first_line += view.size.1 as usize + PADDING;
+pub fn page_down(cx: &mut Context) {
+    cx.view.first_line += cx.view.size.1 as usize + PADDING;
 
-    if view.first_line < view.doc.text().len_lines() {
-        let text = view.doc.text();
-        let pos = text.line_to_char(view.first_line as usize);
-        view.doc.set_selection(Selection::point(pos));
+    if cx.view.first_line < cx.view.doc.text().len_lines() {
+        let text = cx.view.doc.text();
+        let pos = text.line_to_char(cx.view.first_line as usize);
+        cx.view.doc.set_selection(Selection::point(pos));
     }
 }
 
-pub fn half_page_up(view: &mut View, _count: usize) {
-    if view.first_line < PADDING {
+pub fn half_page_up(cx: &mut Context) {
+    if cx.view.first_line < PADDING {
         return;
     }
 
-    view.first_line = view.first_line.saturating_sub(view.size.1 as usize / 2);
+    cx.view.first_line = cx
+        .view
+        .first_line
+        .saturating_sub(cx.view.size.1 as usize / 2);
 
-    if !check_cursor_in_view(view) {
-        let text = &view.doc.text();
-        let pos = text.line_to_char(view.last_line() - PADDING);
-        view.doc.set_selection(Selection::point(pos));
+    if !check_cursor_in_view(cx.view) {
+        let text = &cx.view.doc.text();
+        let pos = text.line_to_char(cx.view.last_line() - PADDING);
+        cx.view.doc.set_selection(Selection::point(pos));
     }
 }
 
-pub fn half_page_down(view: &mut View, _count: usize) {
-    let lines = view.doc.text().len_lines();
-    if view.first_line < lines.saturating_sub(view.size.1 as usize) {
-        view.first_line += view.size.1 as usize / 2;
+pub fn half_page_down(cx: &mut Context) {
+    let lines = cx.view.doc.text().len_lines();
+    if cx.view.first_line < lines.saturating_sub(cx.view.size.1 as usize) {
+        cx.view.first_line += cx.view.size.1 as usize / 2;
     }
-    if !check_cursor_in_view(view) {
-        let text = view.doc.text();
-        let pos = text.line_to_char(view.first_line as usize);
-        view.doc.set_selection(Selection::point(pos));
+    if !check_cursor_in_view(cx.view) {
+        let text = cx.view.doc.text();
+        let pos = text.line_to_char(cx.view.first_line as usize);
+        cx.view.doc.set_selection(Selection::point(pos));
     }
 }
 // avoid select by default by having a visual mode switch that makes movements into selects
 
-pub fn extend_char_left(view: &mut View, count: usize) {
+pub fn extend_char_left(cx: &mut Context) {
     let selection =
-        view.doc
+        cx.view
+            .doc
             .state
-            .extend_selection(Direction::Backward, Granularity::Character, count);
-    view.doc.set_selection(selection);
+            .extend_selection(Direction::Backward, Granularity::Character, cx.count);
+    cx.view.doc.set_selection(selection);
 }
 
-pub fn extend_char_right(view: &mut View, count: usize) {
+pub fn extend_char_right(cx: &mut Context) {
     let selection =
-        view.doc
+        cx.view
+            .doc
             .state
-            .extend_selection(Direction::Forward, Granularity::Character, count);
-    view.doc.set_selection(selection);
+            .extend_selection(Direction::Forward, Granularity::Character, cx.count);
+    cx.view.doc.set_selection(selection);
 }
 
-pub fn extend_line_up(view: &mut View, count: usize) {
-    let selection = view
-        .doc
-        .state
-        .extend_selection(Direction::Backward, Granularity::Line, count);
-    view.doc.set_selection(selection);
+pub fn extend_line_up(cx: &mut Context) {
+    let selection =
+        cx.view
+            .doc
+            .state
+            .extend_selection(Direction::Backward, Granularity::Line, cx.count);
+    cx.view.doc.set_selection(selection);
 }
 
-pub fn extend_line_down(view: &mut View, count: usize) {
-    let selection = view
-        .doc
-        .state
-        .extend_selection(Direction::Forward, Granularity::Line, count);
-    view.doc.set_selection(selection);
+pub fn extend_line_down(cx: &mut Context) {
+    let selection =
+        cx.view
+            .doc
+            .state
+            .extend_selection(Direction::Forward, Granularity::Line, cx.count);
+    cx.view.doc.set_selection(selection);
 }
 
-pub fn split_selection_on_newline(view: &mut View, _count: usize) {
-    let text = &view.doc.text().slice(..);
+pub fn split_selection_on_newline(cx: &mut Context) {
+    let text = &cx.view.doc.text().slice(..);
     // only compile the regex once
     #[allow(clippy::trivial_regex)]
     static REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"\n").unwrap());
-    let selection = selection::split_on_matches(text, view.doc.selection(), &REGEX);
-    view.doc.set_selection(selection);
+    let selection = selection::split_on_matches(text, cx.view.doc.selection(), &REGEX);
+    cx.view.doc.set_selection(selection);
 }
 
-pub fn select_line(view: &mut View, _count: usize) {
+pub fn select_line(cx: &mut Context) {
     // TODO: count
-    let pos = view.doc.selection().primary();
-    let text = view.doc.text();
+    let pos = cx.view.doc.selection().primary();
+    let text = cx.view.doc.text();
     let line = text.char_to_line(pos.head);
     let start = text.line_to_char(line);
     let end = text.line_to_char(line + 1).saturating_sub(1);
 
-    view.doc.set_selection(Selection::single(start, end));
+    cx.view.doc.set_selection(Selection::single(start, end));
 }
 
-pub fn delete_selection(view: &mut View, _count: usize) {
-    let transaction = Transaction::change_by_selection(&view.doc.state, |range| {
+pub fn delete_selection(cx: &mut Context) {
+    let transaction = Transaction::change_by_selection(&cx.view.doc.state, |range| {
         (range.from(), range.to() + 1, None)
     });
-    view.doc.apply(&transaction);
+    cx.view.doc.apply(&transaction);
 
-    append_changes_to_history(view);
+    append_changes_to_history(cx);
 }
 
-pub fn change_selection(view: &mut View, count: usize) {
-    delete_selection(view, count);
-    insert_mode(view, count);
+pub fn change_selection(cx: &mut Context) {
+    delete_selection(cx);
+    insert_mode(cx);
 }
 
-pub fn collapse_selection(view: &mut View, _count: usize) {
-    let selection = view
+pub fn collapse_selection(cx: &mut Context) {
+    let selection = cx
+        .view
         .doc
         .selection()
         .transform(|range| Range::new(range.head, range.head));
 
-    view.doc.set_selection(selection);
+    cx.view.doc.set_selection(selection);
 }
 
-pub fn flip_selections(view: &mut View, _count: usize) {
-    let selection = view
+pub fn flip_selections(cx: &mut Context) {
+    let selection = cx
+        .view
         .doc
         .selection()
         .transform(|range| Range::new(range.head, range.anchor));
 
-    view.doc.set_selection(selection);
+    cx.view.doc.set_selection(selection);
 }
 
-fn enter_insert_mode(view: &mut View) {
-    view.doc.mode = Mode::Insert;
+fn enter_insert_mode(cx: &mut Context) {
+    cx.view.doc.mode = Mode::Insert;
 
-    append_changes_to_history(view);
+    append_changes_to_history(cx);
 }
 // inserts at the start of each selection
-pub fn insert_mode(view: &mut View, _count: usize) {
-    enter_insert_mode(view);
+pub fn insert_mode(cx: &mut Context) {
+    enter_insert_mode(cx);
 
-    let selection = view
+    let selection = cx
+        .view
         .doc
         .selection()
         .transform(|range| Range::new(range.to(), range.from()));
-    view.doc.set_selection(selection);
+    cx.view.doc.set_selection(selection);
 }
 
 // inserts at the end of each selection
-pub fn append_mode(view: &mut View, _count: usize) {
-    enter_insert_mode(view);
-    view.doc.restore_cursor = true;
+pub fn append_mode(cx: &mut Context) {
+    enter_insert_mode(cx);
+    cx.view.doc.restore_cursor = true;
 
     // TODO: as transaction
-    let text = &view.doc.text().slice(..);
-    let selection = view.doc.selection().transform(|range| {
+    let text = &cx.view.doc.text().slice(..);
+    let selection = cx.view.doc.selection().transform(|range| {
         // TODO: to() + next char
         Range::new(
             range.from(),
             graphemes::next_grapheme_boundary(text, range.to()),
         )
     });
-    view.doc.set_selection(selection);
+    cx.view.doc.set_selection(selection);
 }
 
 // TODO: I, A, o and O can share a lot of the primitives.
@@ -332,30 +352,30 @@ fn selection_lines(state: &State) -> Vec<usize> {
 }
 
 // I inserts at the start of each line with a selection
-pub fn prepend_to_line(view: &mut View, count: usize) {
-    enter_insert_mode(view);
+pub fn prepend_to_line(cx: &mut Context) {
+    enter_insert_mode(cx);
 
-    move_line_start(view, count);
+    move_line_start(cx);
 }
 
 // A inserts at the end of each line with a selection
-pub fn append_to_line(view: &mut View, count: usize) {
-    enter_insert_mode(view);
+pub fn append_to_line(cx: &mut Context) {
+    enter_insert_mode(cx);
 
-    move_line_end(view, count);
+    move_line_end(cx);
 }
 
 // o inserts a new line after each line with a selection
-pub fn open_below(view: &mut View, _count: usize) {
-    enter_insert_mode(view);
+pub fn open_below(cx: &mut Context) {
+    enter_insert_mode(cx);
 
-    let lines = selection_lines(&view.doc.state);
+    let lines = selection_lines(&cx.view.doc.state);
 
     let positions: Vec<_> = lines
         .into_iter()
         .map(|index| {
             // adjust all positions to the end of the line/start of the next one.
-            view.doc.text().line_to_char(index + 1)
+            cx.view.doc.text().line_to_char(index + 1)
         })
         .collect();
 
@@ -376,82 +396,85 @@ pub fn open_below(view: &mut View, _count: usize) {
         0,
     );
 
-    let transaction = Transaction::change(&view.doc.state, changes).with_selection(selection);
+    let transaction = Transaction::change(&cx.view.doc.state, changes).with_selection(selection);
 
-    view.doc.apply(&transaction);
+    cx.view.doc.apply(&transaction);
 }
 
 // O inserts a new line before each line with a selection
 
-fn append_changes_to_history(view: &mut View) {
-    if view.doc.changes.is_empty() {
+fn append_changes_to_history(cx: &mut Context) {
+    if cx.view.doc.changes.is_empty() {
         return;
     }
 
-    let new_changeset = ChangeSet::new(view.doc.text());
-    let changes = std::mem::replace(&mut view.doc.changes, new_changeset);
+    let new_changeset = ChangeSet::new(cx.view.doc.text());
+    let changes = std::mem::replace(&mut cx.view.doc.changes, new_changeset);
     // Instead of doing this messy merge we could always commit, and based on transaction
     // annotations either add a new layer or compose into the previous one.
-    let transaction = Transaction::from(changes).with_selection(view.doc.selection().clone());
+    let transaction = Transaction::from(changes).with_selection(cx.view.doc.selection().clone());
 
     // increment document version
     // TODO: needs to happen on undo/redo too
-    view.doc.version += 1;
+    cx.view.doc.version += 1;
 
     // TODO: trigger lsp/documentDidChange with changes
 
     // HAXX: we need to reconstruct the state as it was before the changes..
-    let old_state = std::mem::replace(&mut view.doc.old_state, view.doc.state.clone());
+    let old_state = std::mem::replace(&mut cx.view.doc.old_state, cx.view.doc.state.clone());
     // TODO: take transaction by value?
-    view.doc.history.commit_revision(&transaction, &old_state);
+    cx.view
+        .doc
+        .history
+        .commit_revision(&transaction, &old_state);
 
     // TODO: notify LSP of changes
 }
 
-pub fn normal_mode(view: &mut View, _count: usize) {
-    view.doc.mode = Mode::Normal;
+pub fn normal_mode(cx: &mut Context) {
+    cx.view.doc.mode = Mode::Normal;
 
-    append_changes_to_history(view);
+    append_changes_to_history(cx);
 
     // if leaving append mode, move cursor back by 1
-    if view.doc.restore_cursor {
-        let text = &view.doc.text().slice(..);
-        let selection = view.doc.selection().transform(|range| {
+    if cx.view.doc.restore_cursor {
+        let text = &cx.view.doc.text().slice(..);
+        let selection = cx.view.doc.selection().transform(|range| {
             Range::new(
                 range.from(),
                 graphemes::prev_grapheme_boundary(text, range.to()),
             )
         });
-        view.doc.set_selection(selection);
+        cx.view.doc.set_selection(selection);
 
-        view.doc.restore_cursor = false;
+        cx.view.doc.restore_cursor = false;
     }
 }
 
-pub fn goto_mode(view: &mut View, _count: usize) {
-    view.doc.mode = Mode::Goto;
+pub fn goto_mode(cx: &mut Context) {
+    cx.view.doc.mode = Mode::Goto;
 }
 
 // NOTE: Transactions in this module get appended to history when we switch back to normal mode.
 pub mod insert {
     use super::*;
     // TODO: insert means add text just before cursor, on exit we should be on the last letter.
-    pub fn insert_char(view: &mut View, c: char) {
+    pub fn insert_char(cx: &mut Context, c: char) {
         let c = Tendril::from_char(c);
-        let transaction = Transaction::insert(&view.doc.state, c);
+        let transaction = Transaction::insert(&cx.view.doc.state, c);
 
-        view.doc.apply(&transaction);
+        cx.view.doc.apply(&transaction);
     }
 
-    pub fn insert_tab(view: &mut View, _count: usize) {
-        insert_char(view, '\t');
+    pub fn insert_tab(cx: &mut Context) {
+        insert_char(cx, '\t');
     }
 
-    pub fn insert_newline(view: &mut View, _count: usize) {
-        let transaction = Transaction::change_by_selection(&view.doc.state, |range| {
+    pub fn insert_newline(cx: &mut Context) {
+        let transaction = Transaction::change_by_selection(&cx.view.doc.state, |range| {
             let indent_level = helix_core::indent::suggested_indent_for_pos(
-                view.doc.syntax.as_ref(),
-                &view.doc.state,
+                cx.view.doc.syntax.as_ref(),
+                &cx.view.doc.state,
                 range.head,
             );
             let indent = " ".repeat(TAB_WIDTH).repeat(indent_level);
@@ -460,32 +483,32 @@ pub mod insert {
             text.push_str(&indent);
             (range.head, range.head, Some(text.into()))
         });
-        view.doc.apply(&transaction);
+        cx.view.doc.apply(&transaction);
     }
 
     // TODO: handle indent-aware delete
-    pub fn delete_char_backward(view: &mut View, count: usize) {
-        let text = &view.doc.text().slice(..);
-        let transaction = Transaction::change_by_selection(&view.doc.state, |range| {
+    pub fn delete_char_backward(cx: &mut Context) {
+        let text = &cx.view.doc.text().slice(..);
+        let transaction = Transaction::change_by_selection(&cx.view.doc.state, |range| {
             (
-                graphemes::nth_prev_grapheme_boundary(text, range.head, count),
+                graphemes::nth_prev_grapheme_boundary(text, range.head, cx.count),
                 range.head,
                 None,
             )
         });
-        view.doc.apply(&transaction);
+        cx.view.doc.apply(&transaction);
     }
 
-    pub fn delete_char_forward(view: &mut View, count: usize) {
-        let text = &view.doc.text().slice(..);
-        let transaction = Transaction::change_by_selection(&view.doc.state, |range| {
+    pub fn delete_char_forward(cx: &mut Context) {
+        let text = &cx.view.doc.text().slice(..);
+        let transaction = Transaction::change_by_selection(&cx.view.doc.state, |range| {
             (
                 range.head,
-                graphemes::nth_next_grapheme_boundary(text, range.head, count),
+                graphemes::nth_next_grapheme_boundary(text, range.head, cx.count),
                 None,
             )
         });
-        view.doc.apply(&transaction);
+        cx.view.doc.apply(&transaction);
     }
 }
 
@@ -495,31 +518,32 @@ pub fn insert_char_prompt(prompt: &mut Prompt, c: char) {
 
 // Undo / Redo
 
-pub fn undo(view: &mut View, _count: usize) {
-    if let Some(revert) = view.doc.history.undo() {
-        view.doc.version += 1;
-        view.doc.apply(&revert);
+pub fn undo(cx: &mut Context) {
+    if let Some(revert) = cx.view.doc.history.undo() {
+        cx.view.doc.version += 1;
+        cx.view.doc.apply(&revert);
     }
 
     // TODO: each command could simply return a Option<transaction>, then the higher level handles storing it?
 }
 
-pub fn redo(view: &mut View, _count: usize) {
-    if let Some(transaction) = view.doc.history.redo() {
-        view.doc.version += 1;
-        view.doc.apply(&transaction);
+pub fn redo(cx: &mut Context) {
+    if let Some(transaction) = cx.view.doc.history.redo() {
+        cx.view.doc.version += 1;
+        cx.view.doc.apply(&transaction);
     }
 }
 
 // Yank / Paste
 
-pub fn yank(view: &mut View, _count: usize) {
+pub fn yank(cx: &mut Context) {
     // TODO: should selections be made end inclusive?
-    let values = view
+    let values = cx
+        .view
         .doc
         .state
         .selection()
-        .fragments(&view.doc.text().slice(..))
+        .fragments(&cx.view.doc.text().slice(..))
         .map(|cow| cow.into_owned())
         .collect();
 
@@ -528,7 +552,7 @@ pub fn yank(view: &mut View, _count: usize) {
     register::set(reg, values);
 }
 
-pub fn paste(view: &mut View, _count: usize) {
+pub fn paste(cx: &mut Context) {
     // TODO: allow specifying reg
     let reg = '"';
     if let Some(values) = register::get(reg) {
@@ -560,19 +584,19 @@ pub fn paste(view: &mut View, _count: usize) {
         let transaction = if linewise {
             // paste on the next line
             // TODO: can simply take a range + modifier and compute the right pos without ifs
-            let text = view.doc.text();
-            Transaction::change_by_selection(&view.doc.state, |range| {
+            let text = cx.view.doc.text();
+            Transaction::change_by_selection(&cx.view.doc.state, |range| {
                 let line_end = text.line_to_char(text.char_to_line(range.head) + 1);
                 (line_end, line_end, Some(values.next().unwrap()))
             })
         } else {
-            Transaction::change_by_selection(&view.doc.state, |range| {
+            Transaction::change_by_selection(&cx.view.doc.state, |range| {
                 (range.head + 1, range.head + 1, Some(values.next().unwrap()))
             })
         };
 
-        view.doc.apply(&transaction);
-        append_changes_to_history(view);
+        cx.view.doc.apply(&transaction);
+        append_changes_to_history(cx);
     }
 }
 
@@ -593,29 +617,29 @@ fn get_lines(view: &View) -> Vec<usize> {
     lines
 }
 
-pub fn indent(view: &mut View, _count: usize) {
-    let lines = get_lines(view);
+pub fn indent(cx: &mut Context) {
+    let lines = get_lines(cx.view);
 
     // Indent by one level
     let indent = Tendril::from(" ".repeat(TAB_WIDTH));
 
     let transaction = Transaction::change(
-        &view.doc.state,
+        &cx.view.doc.state,
         lines.into_iter().map(|line| {
-            let pos = view.doc.text().line_to_char(line);
+            let pos = cx.view.doc.text().line_to_char(line);
             (pos, pos, Some(indent.clone()))
         }),
     );
-    view.doc.apply(&transaction);
-    append_changes_to_history(view);
+    cx.view.doc.apply(&transaction);
+    append_changes_to_history(cx);
 }
 
-pub fn unindent(view: &mut View, _count: usize) {
-    let lines = get_lines(view);
+pub fn unindent(cx: &mut Context) {
+    let lines = get_lines(cx.view);
     let mut changes = Vec::with_capacity(lines.len());
 
     for line_idx in lines {
-        let line = view.doc.text().line(line_idx);
+        let line = cx.view.doc.text().line(line_idx);
         let mut width = 0;
 
         for ch in line.chars() {
@@ -631,18 +655,18 @@ pub fn unindent(view: &mut View, _count: usize) {
         }
 
         if width > 0 {
-            let start = view.doc.text().line_to_char(line_idx);
+            let start = cx.view.doc.text().line_to_char(line_idx);
             changes.push((start, start + width, None))
         }
     }
 
-    let transaction = Transaction::change(&view.doc.state, changes.into_iter());
+    let transaction = Transaction::change(&cx.view.doc.state, changes.into_iter());
 
-    view.doc.apply(&transaction);
-    append_changes_to_history(view);
+    cx.view.doc.apply(&transaction);
+    append_changes_to_history(cx);
 }
 
-pub fn indent_selection(_view: &mut View, _count: usize) {
+pub fn indent_selection(_cx: &mut Context) {
     // loop over each line and recompute proper indentation
     unimplemented!()
 }

From 3f707c19f46284d745568c632a57103eb1be4dd4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Fri, 30 Oct 2020 17:00:30 +0900
Subject: [PATCH 21/23] Save command

---
 Cargo.lock                 |  1 +
 helix-term/src/main.rs     | 12 +++---------
 helix-view/Cargo.toml      |  2 ++
 helix-view/src/commands.rs | 12 ++++++++++--
 helix-view/src/document.rs | 25 +++++++++++++++++++++++++
 5 files changed, 41 insertions(+), 11 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 28fc503c..e89696ad 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -523,6 +523,7 @@ dependencies = [
  "crossterm",
  "helix-core",
  "once_cell",
+ "smol",
  "tui",
  "url",
 ]
diff --git a/helix-term/src/main.rs b/helix-term/src/main.rs
index f91c1c8f..9378d3ee 100644
--- a/helix-term/src/main.rs
+++ b/helix-term/src/main.rs
@@ -70,16 +70,10 @@ fn main() -> Result<(), Error> {
         std::thread::spawn(move || smol::block_on(EX.run(smol::future::pending::<()>())));
     }
 
-    // let mut lsp = helix_lsp::Client::start(&EX, "rust-analyzer", &[]);
+    let mut app = Application::new(args, &EX).unwrap();
 
-    smol::block_on(async {
-        // let res = lsp.initialize().await;
-        // let state = helix_core::State::load("test.rs".into(), &[]).unwrap();
-        // let res = lsp.text_document_did_open(&state).await;
-        // loop {}
-
-        Application::new(args, &EX).unwrap().run().await;
-    });
+    // we use the thread local executor to spawn the application task separately from the work pool
+    smol::block_on(app.run());
 
     Ok(())
 }
diff --git a/helix-view/Cargo.toml b/helix-view/Cargo.toml
index 9d53f929..0a48b721 100644
--- a/helix-view/Cargo.toml
+++ b/helix-view/Cargo.toml
@@ -20,3 +20,5 @@ tui = { git = "https://github.com/fdehau/tui-rs", default-features = false, feat
 crossterm = { version = "0.18", features = ["event-stream"], optional = true}
 once_cell = "1.4"
 url = "2"
+
+smol = "1"
diff --git a/helix-view/src/commands.rs b/helix-view/src/commands.rs
index 26c7a190..c135a3da 100644
--- a/helix-view/src/commands.rs
+++ b/helix-view/src/commands.rs
@@ -331,8 +331,7 @@ pub fn append_mode(cx: &mut Context) {
 }
 
 // TODO: I, A, o and O can share a lot of the primitives.
-
-pub fn command_mode(_view: &mut View, _count: usize) {
+pub fn command_mode(_cx: &mut Context) {
     unimplemented!()
 }
 
@@ -670,3 +669,12 @@ pub fn indent_selection(_cx: &mut Context) {
     // loop over each line and recompute proper indentation
     unimplemented!()
 }
+
+//
+
+pub fn save(cx: &mut Context) {
+    // Spawns an async task to actually do the saving. This way we prevent blocking.
+
+    // TODO: handle save errors somehow?
+    cx.executor.spawn(cx.view.doc.save()).detach();
+}
diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
index 710ea4f8..1587de8b 100644
--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -1,4 +1,5 @@
 use anyhow::Error;
+use std::future::Future;
 use std::path::PathBuf;
 
 use helix_core::{
@@ -97,6 +98,30 @@ impl Document {
         Ok(doc)
     }
 
+    pub fn save(&self) -> impl Future<Output = Result<(), anyhow::Error>> {
+        // we clone and move text + path into the future so that we asynchronously save the current
+        // state without blocking any further edits.
+
+        let text = self.text().clone();
+        let path = self.path.clone().expect("Can't save with no path set!"); // TODO: handle no path
+
+        // TODO: mark changes up to now as saved
+        // TODO: mark dirty false
+
+        async move {
+            use smol::{fs::File, prelude::*};
+            let mut file = File::create(path).await?;
+
+            // write all the rope chunks to file
+            for chunk in text.chunks() {
+                file.write_all(chunk.as_bytes()).await?;
+            }
+            // TODO: flush?
+
+            Ok(())
+        } // and_then(// lsp.send_text_saved_notification())
+    }
+
     pub fn set_language(&mut self, scope: &str, scopes: &[String]) {
         if let Some(language_config) = LOADER.language_config_for_scope(scope) {
             let highlight_config = language_config.highlight_config(scopes).unwrap().unwrap();

From a7869c728c663f255d5d2544e42f21ccf57b2414 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Thu, 5 Nov 2020 15:15:19 +0900
Subject: [PATCH 22/23] wip

---
 Cargo.lock                    | 68 ++++++++++++++++-------------------
 helix-core/src/syntax.rs      |  4 +++
 helix-lsp/Cargo.toml          |  1 +
 helix-lsp/src/lib.rs          | 53 +++++++++++++++++++++++++++
 helix-term/src/application.rs | 12 +++++--
 helix-view/src/document.rs    | 15 ++++++++
 6 files changed, 114 insertions(+), 39 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index e89696ad..c9e421a2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,24 +2,18 @@
 # It is not intended for manual editing.
 [[package]]
 name = "aho-corasick"
-version = "0.7.14"
+version = "0.7.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b476ce7103678b0c6d3d395dbbae31d48ff910bd28be979ba5d48c6351131d0d"
+checksum = "7404febffaa47dac81aa44dba71523c9d069b1bdc50a77db41195149e17f68e5"
 dependencies = [
  "memchr",
 ]
 
 [[package]]
 name = "anyhow"
-version = "1.0.33"
+version = "1.0.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1fd36ffbb1fb7c834eac128ea8d0e310c5aeb635548f9d58861e1308d46e71c"
-
-[[package]]
-name = "arc-swap"
-version = "0.4.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4d25d88fd6b8041580a654f9d0c581a047baee2b3efee13275f2fc392fc75034"
+checksum = "bf8dcb5b4bbaa28653b647d8c77bd4ed40183b48882e130c1f1ffb73de069fd7"
 
 [[package]]
 name = "arrayref"
@@ -158,9 +152,9 @@ checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 
 [[package]]
 name = "blake2b_simd"
-version = "0.5.10"
+version = "0.5.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d8fb2d74254a3a0b5cac33ac9f8ed0e44aa50378d9dbb2e5d83bd21ed1dc2c8a"
+checksum = "afa748e348ad3be8263be728124b24a24f268266f6f5d58af9d75f6a40b5c587"
 dependencies = [
  "arrayref",
  "arrayvec",
@@ -279,9 +273,9 @@ dependencies = [
 
 [[package]]
 name = "crossterm"
-version = "0.18.1"
+version = "0.18.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cef9149b29071d44c9fb98fd9c27fcf74405bbdb761889ad6a03f36be93b0b15"
+checksum = "4e86d73f2a0b407b5768d10a8c720cf5d2df49a9efc10ca09176d201ead4b7fb"
 dependencies = [
  "bitflags",
  "crossterm_winapi",
@@ -479,6 +473,7 @@ dependencies = [
  "jsonrpc-core",
  "log",
  "lsp-types",
+ "once_cell",
  "pathdiff",
  "serde",
  "serde_json",
@@ -653,15 +648,15 @@ checksum = "7ffc5c5338469d4d3ea17d269fa8ea3512ad247247c30bd2df69e68309ed0a08"
 
 [[package]]
 name = "memchr"
-version = "2.3.3"
+version = "2.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3728d817d99e5ac407411fa471ff9800a778d88a24685968b36824eaf4bee400"
+checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
 
 [[package]]
 name = "mio"
-version = "0.7.4"
+version = "0.7.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8f1c83949125de4a582aa2da15ae6324d91cf6a58a70ea407643941ff98f558"
+checksum = "8962c171f57fcfffa53f4df1bb15ec4c8cf26a7569459c9ceb62d94aab0d9584"
 dependencies = [
  "libc",
  "log",
@@ -707,9 +702,9 @@ dependencies = [
 
 [[package]]
 name = "num-integer"
-version = "0.1.43"
+version = "0.1.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8d59457e662d541ba17869cf51cf177c0b5f0cbf476c66bdc90bf1edac4f875b"
+checksum = "d2cc698a63b549a70bc047073d2949cce27cd1c7b0a4a862d08a8031bc2801db"
 dependencies = [
  "autocfg",
  "num-traits",
@@ -717,9 +712,9 @@ dependencies = [
 
 [[package]]
 name = "num-traits"
-version = "0.2.12"
+version = "0.2.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac267bcc07f48ee5f8935ab0d24f316fb722d7a1292e2913f0cc196b29ffd611"
+checksum = "9a64b1ec5cda2586e284722486d802acf1f7dbdc623e2bfc57e65ca1cd099290"
 dependencies = [
  "autocfg",
 ]
@@ -837,9 +832,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro-hack"
-version = "0.5.18"
+version = "0.5.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "99c605b9a0adc77b7211c6b1f722dcb613d68d66859a44f3d485a6da332b0598"
+checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
 
 [[package]]
 name = "proc-macro-nested"
@@ -884,9 +879,9 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.4.1"
+version = "1.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8963b85b8ce3074fecffde43b4b0dded83ce2f367dc8d363afc56679f3ee820b"
+checksum = "38cf2c13ed4745de91a5eb834e11c00bcc3709e773173b2ce4c56c9fbde04b9c"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -896,9 +891,9 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.6.20"
+version = "0.6.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8cab7a364d15cde1e505267766a2d3c4e22a843e1a601f0fa7564c0f82ced11c"
+checksum = "3b181ba2dcf07aaccad5448e8ead58db5b742cf85dfe035e2227f137a539a189"
 
 [[package]]
 name = "ropey"
@@ -997,11 +992,10 @@ dependencies = [
 
 [[package]]
 name = "signal-hook-registry"
-version = "1.2.1"
+version = "1.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a3e12110bc539e657a646068aaf5eb5b63af9d0c1f7b29c97113fad80e15f035"
+checksum = "ce32ea0c6c56d5eacaeb814fbed9960547021d3edd010ded1425f180536b20ab"
 dependencies = [
- "arc-swap",
  "libc",
 ]
 
@@ -1079,18 +1073,18 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.21"
+version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "318234ffa22e0920fe9a40d7b8369b5f649d490980cf7aadcf1eb91594869b42"
+checksum = "0e9ae34b84616eedaaf1e9dd6026dbe00dcafa92aa0c8077cb69df1fcfe5e53e"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.21"
+version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cae2447b6282786c3493999f40a9be2a6ad20cb8bd268b0a0dbf5a065535c0ab"
+checksum = "9ba20f23e85b10754cd195504aebf6a27e2e6cbe28c17778a0c930724628dd56"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1125,9 +1119,9 @@ checksum = "238ce071d267c5710f9d31451efec16c5ee22de34df17cc05e56cbc92e967117"
 
 [[package]]
 name = "tree-sitter"
-version = "0.17.0"
+version = "0.17.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70ee7370fec3aecde3862a7d64c571048f70a7298daef1815e8fc68b9de54b5c"
+checksum = "d18dcb776d3affaba6db04d11d645946d34a69b3172e588af96ce9fecd20faac"
 dependencies = [
  "cc",
  "regex",
diff --git a/helix-core/src/syntax.rs b/helix-core/src/syntax.rs
index f4826fb4..70d42c47 100644
--- a/helix-core/src/syntax.rs
+++ b/helix-core/src/syntax.rs
@@ -62,6 +62,10 @@ impl LanguageConfiguration {
             })
             .map(Option::as_ref)
     }
+
+    pub fn scope(&self) -> &str {
+        &self.scope
+    }
 }
 
 use once_cell::sync::Lazy;
diff --git a/helix-lsp/Cargo.toml b/helix-lsp/Cargo.toml
index 0c5d8b91..08216f59 100644
--- a/helix-lsp/Cargo.toml
+++ b/helix-lsp/Cargo.toml
@@ -9,6 +9,7 @@ edition = "2018"
 [dependencies]
 helix-core = { path = "../helix-core" }
 helix-view = { path = "../helix-view" }
+once_cell = "1.4"
 
 lsp-types = { version = "0.83", features = ["proposed"] }
 smol = "1.2"
diff --git a/helix-lsp/src/lib.rs b/helix-lsp/src/lib.rs
index 1ee8199f..8353ef7d 100644
--- a/helix-lsp/src/lib.rs
+++ b/helix-lsp/src/lib.rs
@@ -4,11 +4,15 @@ mod transport;
 pub use jsonrpc_core as jsonrpc;
 pub use lsp_types as lsp;
 
+pub use once_cell::sync::{Lazy, OnceCell};
+
 pub use client::Client;
 pub use lsp::{Position, Url};
 
 use thiserror::Error;
 
+use std::{collections::HashMap, sync::Arc};
+
 #[derive(Error, Debug)]
 pub enum Error {
     #[error("protocol error: {0}")]
@@ -62,3 +66,52 @@ impl Notification {
 }
 
 pub use jsonrpc::Call;
+
+type LanguageId = String;
+
+pub static REGISTRY: Lazy<Registry> = Lazy::new(Registry::init);
+
+pub struct Registry {
+    inner: HashMap<LanguageId, OnceCell<Arc<Client>>>,
+}
+
+impl Registry {
+    pub fn init() -> Self {
+        Self {
+            inner: HashMap::new(),
+        }
+    }
+
+    pub fn get(&self, id: &str, ex: &smol::Executor) -> Option<Arc<Client>> {
+        // TODO: use get_or_try_init and propagate the error
+        self.inner
+            .get(id)
+            .map(|cell| {
+                cell.get_or_init(|| {
+                    // TODO: lookup defaults for id (name, args)
+
+                    // initialize a new client
+                    let client = Client::start(&ex, "rust-analyzer", &[]);
+                    // TODO: also call initialize().await()
+                    Arc::new(client)
+                })
+            })
+            .cloned()
+    }
+}
+
+// REGISTRY = HashMap<LanguageId, Lazy/OnceCell<Arc<RwLock<Client>>>
+// spawn one server per language type, need to spawn one per workspace if server doesn't support
+// workspaces
+//
+// could also be a client per root dir
+//
+// storing a copy of Option<Arc<RwLock<Client>>> on Document would make the LSP client easily
+// accessible during edit/save callbacks
+//
+// the event loop needs to process all incoming streams, maybe we can just have that be a separate
+// task that's continually running and store the state on the client, then use read lock to
+// retrieve data during render
+// -> PROBLEM: how do you trigger an update on the editor side when data updates?
+//
+// -> The data updates should pull all events until we run out so we don't frequently re-render
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index cacfde56..141779ec 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -636,9 +636,17 @@ impl<'a> Application<'a> {
                 }
             }
             Some(Call::MethodCall(call)) => {
-                // TODO: need to make Result<Value, Error>
+                debug!("Method not found {}", call.method);
 
-                unimplemented!("{:?}", call)
+                self.language_server.reply(
+                    call.id,
+                    // TODO: make a Into trait that can cast to Err(jsonrpc::Error)
+                    Err(helix_lsp::jsonrpc::Error {
+                        code: helix_lsp::jsonrpc::ErrorCode::MethodNotFound,
+                        message: "Method not found".to_string(),
+                        data: None,
+                    }),
+                );
             }
             _ => unreachable!(),
         }
diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
index 1587de8b..e8f311c5 100644
--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -25,6 +25,8 @@ pub struct Document {
 
     /// Tree-sitter AST tree
     pub syntax: Option<Syntax>,
+    /// Corresponding language scope name. Usually `source.<lang>`.
+    pub language: Option<String>,
 
     /// Pending changes since last history commit.
     pub changes: ChangeSet,
@@ -64,6 +66,7 @@ impl Document {
             mode: Mode::Normal,
             restore_cursor: false,
             syntax: None,
+            language: None,
             changes,
             old_state,
             diagnostics: Vec::new(),
@@ -73,6 +76,7 @@ impl Document {
     }
 
     // TODO: passing scopes here is awkward
+    // TODO: async fn?
     pub fn load(path: PathBuf, scopes: &[String]) -> Result<Self, Error> {
         use std::{env, fs::File, io::BufReader};
         let _current_dir = env::current_dir()?;
@@ -90,6 +94,15 @@ impl Document {
             let syntax = Syntax::new(&doc.state.doc, highlight_config.clone());
 
             doc.syntax = Some(syntax);
+            // TODO: maybe just keep an Arc<> pointer to the language_config?
+            doc.language = Some(language_config.scope().to_string());
+
+            // TODO: this ties lsp support to tree-sitter enabled languages for now. Language
+            // config should use Option<HighlightConfig> to let us have non-tree-sitter configs.
+
+            // TODO: circular dep: view <-> lsp
+            // helix_lsp::REGISTRY;
+            // view should probably depend on lsp
         };
 
         // canonicalize path to absolute value
@@ -98,6 +111,8 @@ impl Document {
         Ok(doc)
     }
 
+    // TODO: do we need some way of ensuring two save operations on the same doc can't run at once?
+    // or is that handled by the OS/async layer
     pub fn save(&self) -> impl Future<Output = Result<(), anyhow::Error>> {
         // we clone and move text + path into the future so that we asynchronously save the current
         // state without blocking any further edits.

From 39bf1ca82514e1dc56dfebdce2558cce662367d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Tue, 1 Dec 2020 09:53:17 +0900
Subject: [PATCH 23/23] Update deps.

---
 Cargo.lock                 | 150 ++++++++++++++++++++++---------------
 helix-lsp/Cargo.toml       |   2 +-
 helix-lsp/src/client.rs    |   3 +-
 helix-lsp/src/lib.rs       |   2 +-
 helix-view/src/document.rs |   2 +-
 5 files changed, 93 insertions(+), 66 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index c9e421a2..a3e93bd7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -40,9 +40,9 @@ dependencies = [
 
 [[package]]
 name = "async-executor"
-version = "1.3.0"
+version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d373d78ded7d0b3fa8039375718cde0aace493f2e34fb60f51cbf567562ca801"
+checksum = "eb877970c7b440ead138f6321a3b5395d6061183af779340b65e20c0fede9146"
 dependencies = [
  "async-task",
  "concurrent-queue",
@@ -65,9 +65,9 @@ dependencies = [
 
 [[package]]
 name = "async-io"
-version = "1.1.10"
+version = "1.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d54bc4c1c7292475efb2253227dbcfad8fe1ca4c02bc62c510cc2f3da5c4704e"
+checksum = "9315f8f07556761c3e48fec2e6b276004acf426e6dc068b2c2251854d65ee0fd"
 dependencies = [
  "concurrent-queue",
  "fastrand",
@@ -144,6 +144,12 @@ version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3441f0f7b02788e948e47f457ca01f1d7e6d92c693bc132c22b087d3141c03ff"
 
+[[package]]
+name = "base64"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "904dfeac50f3cdaba28fc6f57fdcddb75f49ed61346676a78c4ffe55877802fd"
+
 [[package]]
 name = "bitflags"
 version = "1.2.1"
@@ -189,9 +195,9 @@ checksum = "df8670b8c7b9dae1793364eafadf7239c40d669904660c5960d74cfd80b46a53"
 
 [[package]]
 name = "cc"
-version = "1.0.61"
+version = "1.0.65"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed67cbde08356238e75fc4656be4749481eeffb09e19f320a25237d5221c985d"
+checksum = "95752358c8f7552394baf48cd82695b345628ad3f170d607de3ca03b8dacca15"
 dependencies = [
  "jobserver",
 ]
@@ -262,12 +268,12 @@ checksum = "245097e9a4535ee1e3e3931fcfcd55a796a44c643e8596ff6566d68f09b87bbc"
 
 [[package]]
 name = "crossbeam-utils"
-version = "0.7.2"
+version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c3c7c73a2d1e9fc0886a08b93e98eb643461230d5f1925e4036204d5f2e261a8"
+checksum = "02d96d1e189ef58269ebe5b97953da3274d83a93af647c2ddd6f9dab28cedb8d"
 dependencies = [
  "autocfg",
- "cfg-if 0.1.10",
+ "cfg-if 1.0.0",
  "lazy_static",
 ]
 
@@ -342,6 +348,16 @@ dependencies = [
  "log",
 ]
 
+[[package]]
+name = "form_urlencoded"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ece68d15c92e84fa4f19d3780f1294e5ca82a78a6d515f1efaabcc144688be00"
+dependencies = [
+ "matches",
+ "percent-encoding",
+]
+
 [[package]]
 name = "futf"
 version = "0.1.4"
@@ -360,15 +376,15 @@ checksum = "4c7e4c2612746b0df8fed4ce0c69156021b704c9aefa360311c04e6e9e002eed"
 
 [[package]]
 name = "futures-core"
-version = "0.3.7"
+version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "18eaa56102984bed2c88ea39026cff3ce3b4c7f508ca970cedf2450ea10d4e46"
+checksum = "847ce131b72ffb13b6109a221da9ad97a64cbe48feb1028356b836b47b8f1748"
 
 [[package]]
 name = "futures-io"
-version = "0.3.7"
+version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e1798854a4727ff944a7b12aa999f58ce7aa81db80d2dfaaf2ba06f065ddd2b"
+checksum = "611834ce18aaa1bd13c4b374f5d653e1027cf99b6b502584ff8c9a64413b30bb"
 
 [[package]]
 name = "futures-lite"
@@ -387,9 +403,9 @@ dependencies = [
 
 [[package]]
 name = "futures-macro"
-version = "0.3.7"
+version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e36fccf3fc58563b4a14d265027c627c3b665d7fed489427e88e7cc929559efe"
+checksum = "77408a692f1f97bcc61dc001d752e00643408fbc922e4d634c655df50d595556"
 dependencies = [
  "proc-macro-hack",
  "proc-macro2",
@@ -399,18 +415,18 @@ dependencies = [
 
 [[package]]
 name = "futures-task"
-version = "0.3.7"
+version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "96d502af37186c4fef99453df03e374683f8a1eec9dcc1e66b3b82dc8278ce3c"
+checksum = "7c554eb5bf48b2426c4771ab68c6b14468b6e76cc90996f528c3338d761a4d0d"
 dependencies = [
  "once_cell",
 ]
 
 [[package]]
 name = "futures-util"
-version = "0.3.7"
+version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "abcb44342f62e6f3e8ac427b8aa815f724fd705dfad060b18ac7866c15bb8e34"
+checksum = "d304cff4a7b99cfb7986f7d43fbe93d175e72e704a8860787cc95e9ffd85cbd2"
 dependencies = [
  "futures-core",
  "futures-macro",
@@ -555,9 +571,9 @@ dependencies = [
 
 [[package]]
 name = "instant"
-version = "0.1.8"
+version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb1fc4429a33e1f80d41dc9fea4d108a88bec1de8053878898ae448a0b52f613"
+checksum = "61124eeebbd69b8190558df225adf7e4caafce0d743919e5d6b19652314ec5ec"
 dependencies = [
  "cfg-if 1.0.0",
 ]
@@ -604,9 +620,9 @@ checksum = "4d58d1b70b004888f764dfbf6a26a3b0342a1632d33968e4a179d8011c760614"
 
 [[package]]
 name = "lock_api"
-version = "0.4.1"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "28247cc5a5be2f05fbcd76dd0cf2c7d3b5400cb978a28042abcd4fa0b3f8261c"
+checksum = "dd96ffd135b2fd7b973ac026d28085defbe8983df057ced3eb4f2130b0831312"
 dependencies = [
  "scopeguard",
 ]
@@ -622,11 +638,11 @@ dependencies = [
 
 [[package]]
 name = "lsp-types"
-version = "0.83.0"
+version = "0.84.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "25e0bd4b95038f2c23bda332ba0ca684e8dda765db1f9bdb63dc4c3e01f3b456"
+checksum = "3b95be71fe205e44de754185bcf86447b65813ce1ceb298f8d3793ade5fff08d"
 dependencies = [
- "base64",
+ "base64 0.12.3",
  "bitflags",
  "serde",
  "serde_json",
@@ -654,9 +670,9 @@ checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
 
 [[package]]
 name = "mio"
-version = "0.7.5"
+version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8962c171f57fcfffa53f4df1bb15ec4c8cf26a7569459c9ceb62d94aab0d9584"
+checksum = "f33bc887064ef1fd66020c9adfc45bb9f33d75a42096c81e7c56c65b75dd1a8b"
 dependencies = [
  "libc",
  "log",
@@ -667,9 +683,9 @@ dependencies = [
 
 [[package]]
 name = "miow"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "07b88fb9795d4d36d62a012dfbf49a8f5cf12751f36d31a9dbe66d528e58979e"
+checksum = "5a33c1b55807fbed163481b5ba66db4b2fa6cde694a5027be10fb724206c5897"
 dependencies = [
  "socket2",
  "winapi",
@@ -731,15 +747,15 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.4.1"
+version = "1.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "260e51e7efe62b592207e9e13a68e43692a7a279171d6ba57abd208bf23645ad"
+checksum = "13bd41f508810a131401606d54ac32a467c97172d74ba7662562ebba5ad07fa0"
 
 [[package]]
 name = "os_str_bytes"
-version = "2.3.2"
+version = "2.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2ac6fe3538f701e339953a3ebbe4f39941aababa8a3f6964635b24ab526daeac"
+checksum = "afb2e1c3ee07430c2cf76151675e583e0f19985fa6efae47d6848a3e2c824f85"
 
 [[package]]
 name = "parking"
@@ -749,9 +765,9 @@ checksum = "427c3892f9e783d91cc128285287e70a59e206ca452770ece88a76f7a3eddd72"
 
 [[package]]
 name = "parking_lot"
-version = "0.11.0"
+version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4893845fa2ca272e647da5d0e46660a314ead9c2fdd9a883aabc32e481a8733"
+checksum = "6d7744ac029df22dca6284efe4e898991d28e3085c706c972bcd7da4a27a15eb"
 dependencies = [
  "instant",
  "lock_api",
@@ -787,18 +803,18 @@ checksum = "d4fd5641d01c8f18a23da7b6fe29298ff4b55afcccdf78973b24cf3175fee32e"
 
 [[package]]
 name = "pin-project"
-version = "1.0.1"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee41d838744f60d959d7074e3afb6b35c7456d0f61cad38a24e35e6553f73841"
+checksum = "9ccc2237c2c489783abd8c4c80e5450fc0e98644555b1364da68cc29aa151ca7"
 dependencies = [
  "pin-project-internal",
 ]
 
 [[package]]
 name = "pin-project-internal"
-version = "1.0.1"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "81a4ffa594b66bff340084d4081df649a7dc049ac8d7fc458d8e628bfbbb2f86"
+checksum = "f8e8d2bf0b23038a4424865103a4df472855692821aab4e4f5c3312d461d9e5f"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -906,11 +922,11 @@ dependencies = [
 
 [[package]]
 name = "rust-argon2"
-version = "0.8.2"
+version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9dab61250775933275e84053ac235621dfb739556d5c54a2f2e9313b7cf43a19"
+checksum = "4b18820d944b33caa75a71378964ac46f58517c92b6ae5f762636247c09e78fb"
 dependencies = [
- "base64",
+ "base64 0.13.0",
  "blake2b_simd",
  "constant_time_eq",
  "crossbeam-utils",
@@ -1007,15 +1023,15 @@ checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 
 [[package]]
 name = "smallvec"
-version = "1.4.2"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fbee7696b84bbf3d89a1c2eccff0850e3047ed46bfcd2e92c29a2d074d57e252"
+checksum = "7acad6f34eb9e8a259d3283d1e8c1d34d7415943d4895f65cc73813c7396fc85"
 
 [[package]]
 name = "smol"
-version = "1.2.4"
+version = "1.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aaf8ded16994c0ae59596c6e4733c76faeb0533c26fd5ca1b1bc89271a049a66"
+checksum = "85cf3b5351f3e783c1d79ab5fc604eeed8b8ae9abd36b166e8b87a089efd85e4"
 dependencies = [
  "async-channel",
  "async-executor",
@@ -1031,11 +1047,11 @@ dependencies = [
 
 [[package]]
 name = "socket2"
-version = "0.3.15"
+version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b1fa70dc5c8104ec096f4fe7ede7a221d35ae13dcd19ba1ad9a81d2cab9a1c44"
+checksum = "2c29947abdee2a218277abeca306f25789c938e500ea5a9d4b12a5a504466902"
 dependencies = [
- "cfg-if 0.1.10",
+ "cfg-if 1.0.0",
  "libc",
  "redox_syscall",
  "winapi",
@@ -1043,9 +1059,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.48"
+version = "1.0.53"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cc371affeffc477f42a221a1e4297aedcea33d47d19b61455588bd9d8f6b19ac"
+checksum = "8833e20724c24de12bbaba5ad230ea61c3eafb05b881c7c9d3cfe8638b187e68"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1113,9 +1129,18 @@ dependencies = [
 
 [[package]]
 name = "tinyvec"
-version = "0.3.4"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "238ce071d267c5710f9d31451efec16c5ee22de34df17cc05e56cbc92e967117"
+checksum = "ccf8dbc19eb42fba10e8feaaec282fb50e2c14b2726d6301dbfeed0f73306a6f"
+dependencies = [
+ "tinyvec_macros",
+]
+
+[[package]]
+name = "tinyvec_macros"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cda74da7e1a664f795bb1f8a87ec406fb89a02522cf6e50620d016add6dbbf5c"
 
 [[package]]
 name = "tree-sitter"
@@ -1129,8 +1154,8 @@ dependencies = [
 
 [[package]]
 name = "tui"
-version = "0.12.0"
-source = "git+https://github.com/fdehau/tui-rs#25ff2e5e61f8902101e485743992db2412f77aad"
+version = "0.13.0"
+source = "git+https://github.com/fdehau/tui-rs#efdd6bfb193dafcb5e3bdc75e7d2d314065da1d7"
 dependencies = [
  "bitflags",
  "cassowary",
@@ -1150,18 +1175,18 @@ dependencies = [
 
 [[package]]
 name = "unicode-normalization"
-version = "0.1.13"
+version = "0.1.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6fb19cf769fa8c6a80a162df694621ebeb4dafb606470b2b2fce0be40a98a977"
+checksum = "a13e63ab62dbe32aeee58d1c5408d35c36c392bba5d9d3142287219721afe606"
 dependencies = [
  "tinyvec",
 ]
 
 [[package]]
 name = "unicode-segmentation"
-version = "1.6.0"
+version = "1.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e83e153d1053cbb5a118eeff7fd5be06ed99153f00dbcd8ae310c5fb2b22edc0"
+checksum = "bb0d2e7be6ae3a5fa87eed5fb451aff96f2573d2694942e40543ae0bbe19c796"
 
 [[package]]
 name = "unicode-width"
@@ -1177,10 +1202,11 @@ checksum = "f7fe0bb3479651439c9112f72b6c505038574c9fbb575ed1bf3b797fa39dd564"
 
 [[package]]
 name = "url"
-version = "2.1.1"
+version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "829d4a8476c35c9bf0bbce5a3b23f4106f79728039b726d292bb93bc106787cb"
+checksum = "5909f2b0817350449ed73e8bcd81c8c3c8d9a7a5d8acba4b27db277f1868976e"
 dependencies = [
+ "form_urlencoded",
  "idna",
  "matches",
  "percent-encoding",
diff --git a/helix-lsp/Cargo.toml b/helix-lsp/Cargo.toml
index 08216f59..2ecd0cc1 100644
--- a/helix-lsp/Cargo.toml
+++ b/helix-lsp/Cargo.toml
@@ -11,7 +11,7 @@ helix-core = { path = "../helix-core" }
 helix-view = { path = "../helix-view" }
 once_cell = "1.4"
 
-lsp-types = { version = "0.83", features = ["proposed"] }
+lsp-types = { version = "0.84", features = ["proposed"] }
 smol = "1.2"
 url = "2"
 pathdiff = "0.2"
diff --git a/helix-lsp/src/client.rs b/helix-lsp/src/client.rs
index 1583bfb8..1f07cf89 100644
--- a/helix-lsp/src/client.rs
+++ b/helix-lsp/src/client.rs
@@ -183,7 +183,7 @@ impl Client {
 
         #[allow(deprecated)]
         let params = lsp::InitializeParams {
-            process_id: Some(u64::from(std::process::id())),
+            process_id: Some(std::process::id()),
             root_path: None,
             // root_uri: Some(lsp_types::Url::parse("file://localhost/")?),
             root_uri: None, // set to project root in the future
@@ -194,6 +194,7 @@ impl Client {
             trace: None,
             workspace_folders: None,
             client_info: None,
+            locale: None, // TODO
         };
 
         let response = self.request::<lsp::request::Initialize>(params).await?;
diff --git a/helix-lsp/src/lib.rs b/helix-lsp/src/lib.rs
index 8353ef7d..eae6fa86 100644
--- a/helix-lsp/src/lib.rs
+++ b/helix-lsp/src/lib.rs
@@ -38,7 +38,7 @@ pub mod util {
         let line_start = doc.char_to_utf16_cu(line);
         let col = doc.char_to_utf16_cu(pos) - line_start;
 
-        lsp::Position::new(line as u64, col as u64)
+        lsp::Position::new(line as u32, col as u32)
     }
 }
 
diff --git a/helix-view/src/document.rs b/helix-view/src/document.rs
index e8f311c5..7c4596ad 100644
--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -32,7 +32,7 @@ pub struct Document {
     pub changes: ChangeSet,
     pub old_state: State,
     pub history: History,
-    pub version: i64, // should be usize?
+    pub version: i32, // should be usize?
 
     pub diagnostics: Vec<Diagnostic>,
 }