From 71999cce43b3750362cdea534c12cbf320d2677b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Mon, 22 Mar 2021 12:18:48 +0900
Subject: [PATCH] Implement auto-pairs behavior for open and close.
---
helix-core/src/auto_pairs.rs | 117 +++++++++++++++++++++++++++++++++++
helix-core/src/lib.rs | 1 +
helix-core/src/selection.rs | 4 ++
helix-term/src/commands.rs | 15 +++++
4 files changed, 137 insertions(+)
create mode 100644 helix-core/src/auto_pairs.rs
diff --git a/helix-core/src/auto_pairs.rs b/helix-core/src/auto_pairs.rs
new file mode 100644
index 00000000..52a45075
--- /dev/null
+++ b/helix-core/src/auto_pairs.rs
@@ -0,0 +1,117 @@
+use crate::{Range, Rope, Selection, Tendril, Transaction};
+use smallvec::SmallVec;
+
+const PAIRS: &[(char, char)] = &[
+ ('(', ')'),
+ ('{', '}'),
+ ('[', ']'),
+ ('\'', '\''),
+ ('"', '"'),
+ ('`', '`'),
+];
+
+const CLOSE_BEFORE: &str = ")]}'\":;> \n"; // includes space and newline
+
+// insert hook:
+// Fn(doc, selection, char) => Option<Transaction>
+// problem is, we want to do this per range, so we can call default handler for some ranges
+// so maybe ret Vec<Option<Change>>
+// but we also need to be able to return transactions...
+//
+// to simplify, maybe return Option<Transaction> and just reimplement the default
+
+// TODO: delete implementation where it erases the whole bracket (|) -> |
+
+pub fn hook(doc: &Rope, selection: &Selection, ch: char) -> Option<Transaction> {
+ for &(open, close) in PAIRS {
+ if open == ch {
+ let t = if open == close {
+ return None;
+ // handle_same()
+ } else {
+ handle_open(doc, selection, open, close, CLOSE_BEFORE)
+ };
+ return Some(t);
+ }
+
+ if close == ch {
+ // && char_at pos == close
+ return Some(handle_close(doc, selection, open, close));
+ }
+ }
+
+ None
+}
+
+// TODO: special handling for lifetimes in rust: if preceeded by & or < don't auto close '
+// for example "&'a mut", or "fn<'a>"
+
+fn next_char(doc: &Rope, pos: usize) -> Option<char> {
+ if pos >= doc.len_chars() {
+ return None;
+ }
+ Some(doc.char(pos))
+}
+
+// TODO: if not cursor but selection, wrap on both sides of selection (surround)
+fn handle_open(
+ doc: &Rope,
+ selection: &Selection,
+ open: char,
+ close: char,
+ close_before: &str,
+) -> Transaction {
+ let mut ranges = SmallVec::with_capacity(selection.len());
+
+ let mut transaction = Transaction::change_by_selection(doc, selection, |range| {
+ let pos = range.head;
+ let next = next_char(doc, pos);
+
+ ranges.push(Range::new(range.anchor, pos + 1)); // pos + open
+
+ match next {
+ Some(ch) if !close_before.contains(ch) => {
+ // TODO: else return (use default handler that inserts open)
+ (pos, pos, Some(Tendril::from_char(open)))
+ }
+ // None | Some(ch) if close_before.contains(ch) => {}
+ _ => {
+ // insert open & close
+ let mut pair = Tendril::with_capacity(2);
+ pair.push_char(open);
+ pair.push_char(close);
+
+ (pos, pos, Some(pair))
+ }
+ }
+ });
+
+ transaction.with_selection(Selection::new(ranges, selection.primary_index()))
+}
+
+fn handle_close(doc: &Rope, selection: &Selection, _open: char, close: char) -> Transaction {
+ let mut ranges = SmallVec::with_capacity(selection.len());
+
+ let mut transaction = Transaction::change_by_selection(doc, selection, |range| {
+ let pos = range.head;
+ let next = next_char(doc, pos);
+
+ ranges.push(Range::new(range.anchor, pos + 1)); // pos + close
+
+ if next == Some(close) {
+ // return transaction that moves past close
+ (pos, pos, None) // no-op
+ } else {
+ // TODO: else return (use default handler that inserts close)
+ (pos, pos, Some(Tendril::from_char(close)))
+ }
+ });
+
+ transaction.with_selection(Selection::new(ranges, selection.primary_index()))
+}
+
+// handle cases where open and close is the same, or in triples ("""docstring""")
+fn handle_same() {
+ // if not cursor but selection, wrap
+ // let next = next char
+}
diff --git a/helix-core/src/lib.rs b/helix-core/src/lib.rs
index a742ca13..6b991881 100644
--- a/helix-core/src/lib.rs
+++ b/helix-core/src/lib.rs
@@ -1,4 +1,5 @@
#![allow(unused)]
+pub mod auto_pairs;
pub mod comment;
pub mod diagnostic;
pub mod graphemes;
diff --git a/helix-core/src/selection.rs b/helix-core/src/selection.rs
index 91edcf81..2e7104cd 100644
--- a/helix-core/src/selection.rs
+++ b/helix-core/src/selection.rs
@@ -180,6 +180,10 @@ impl Selection {
&self.ranges
}
+ pub fn primary_index(&self) -> usize {
+ self.primary_index
+ }
+
#[must_use]
/// Constructs a selection holding a single range.
pub fn single(anchor: usize, head: usize) -> Self {
diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index 54fea453..f7e137e0 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -1009,9 +1009,23 @@ pub fn goto_reference(cx: &mut Context) {
// NOTE: Transactions in this module get appended to history when we switch back to normal mode.
pub mod insert {
use super::*;
+ pub type Hook = fn(&Rope, &Selection, char) -> Option<Transaction>;
+
+ use helix_core::auto_pairs;
+ const HOOKS: &[Hook] = &[auto_pairs::hook];
+
// TODO: insert means add text just before cursor, on exit we should be on the last letter.
pub fn insert_char(cx: &mut Context, c: char) {
let doc = cx.doc();
+
+ // run through insert hooks, stopping on the first one that returns Some(t)
+ for hook in HOOKS {
+ if let Some(transaction) = hook(doc.text(), doc.selection(), c) {
+ doc.apply(&transaction);
+ return;
+ }
+ }
+
let c = Tendril::from_char(c);
let transaction = Transaction::insert(doc.text(), doc.selection(), c);
@@ -1019,6 +1033,7 @@ pub mod insert {
}
pub fn insert_tab(cx: &mut Context) {
+ // TODO: tab should insert either \t or indent width spaces
insert_char(cx, '\t');
}