From 2dba228c766e5e9e4b0fe0c12d30909f51faa28e Mon Sep 17 00:00:00 2001
From: Nathan Vegdahl <cessen@cessen.com>
Date: Fri, 25 Jun 2021 10:13:51 -0700
Subject: [PATCH] Fix highlight code splitting graphemes.
This resulted in phantom blank lines in files with CRLF line
endings, but could potentially have manifested with other
graphemes as well.
---
helix-core/src/graphemes.rs | 24 ++++++++++++++++++++++++
helix-term/src/ui/editor.rs | 8 +++++---
2 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/helix-core/src/graphemes.rs b/helix-core/src/graphemes.rs
index 2e6a925f..e2f7c3f3 100644
--- a/helix-core/src/graphemes.rs
+++ b/helix-core/src/graphemes.rs
@@ -121,6 +121,30 @@ pub fn next_grapheme_boundary(slice: RopeSlice, char_idx: usize) -> usize {
nth_next_grapheme_boundary(slice, char_idx, 1)
}
+/// Returns the passed char index if it's already a grapheme boundary,
+/// or the next grapheme boundary char index if not.
+pub fn ensure_grapheme_boundary(slice: RopeSlice, char_idx: usize) -> usize {
+ if char_idx == 0 {
+ 0
+ } else {
+ next_grapheme_boundary(slice, char_idx - 1)
+ }
+}
+
+/// Returns the passed byte index if it's already a grapheme boundary,
+/// or the next grapheme boundary byte index if not.
+pub fn ensure_grapheme_boundary_byte(slice: RopeSlice, byte_idx: usize) -> usize {
+ // TODO: we can avoid the byte/char conversions entirely
+ // if we also make byte versions of the other functions.
+ let char_idx = slice.byte_to_char(byte_idx);
+ let fixed_char_idx = ensure_grapheme_boundary(slice, char_idx);
+ if fixed_char_idx == char_idx {
+ byte_idx
+ } else {
+ slice.char_to_byte(fixed_char_idx)
+ }
+}
+
/// Returns whether the given char position is a grapheme boundary.
pub fn is_grapheme_boundary(slice: RopeSlice, char_idx: usize) -> bool {
// Bounds check
diff --git a/helix-term/src/ui/editor.rs b/helix-term/src/ui/editor.rs
index 93f000e7..14cfc7dd 100644
--- a/helix-term/src/ui/editor.rs
+++ b/helix-term/src/ui/editor.rs
@@ -8,6 +8,7 @@ use crate::{
use helix_core::{
coords_at_pos,
+ graphemes::{ensure_grapheme_boundary, ensure_grapheme_boundary_byte},
syntax::{self, HighlightEvent},
LineEnding, Position, Range,
};
@@ -141,7 +142,8 @@ impl EditorView {
'outer: for event in highlights {
match event.unwrap() {
- HighlightEvent::HighlightStart(span) => {
+ HighlightEvent::HighlightStart(mut span) => {
+ span.0 = ensure_grapheme_boundary_byte(text, span.0);
spans.push(span);
}
HighlightEvent::HighlightEnd => {
@@ -151,8 +153,8 @@ impl EditorView {
// TODO: filter out spans out of viewport for now..
// TODO: do these before iterating
- let start = text.byte_to_char(start);
- let end = text.byte_to_char(end);
+ let start = ensure_grapheme_boundary(text, text.byte_to_char(start));
+ let end = ensure_grapheme_boundary(text, text.byte_to_char(end));
let text = text.slice(start..end);