From 11c3ba935041437d11e1105dfa37480f2d27a6c4 Mon Sep 17 00:00:00 2001
From: Blaž Hrastnik
Date: Wed, 12 Jan 2022 10:22:16 +0900
Subject: Speed up ensure_next_boundary during render

This code:

    let start = ensure_grapheme_boundary_next(text, text.byte_to_char(start));
    let end = ensure_grapheme_boundary_next(text, text.byte_to_char(end));

Would convert byte to char index, but then internally immediately convert back
to byte index, operate on it, then convert it to char index.

This change reduces the amount of time spent in ensure_grapheme_boundary from
29% to 2%.
---
 helix-term/src/ui/editor.rs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

(limited to 'helix-term')

diff --git a/helix-term/src/ui/editor.rs b/helix-term/src/ui/editor.rs
index acf6b8d8..956db72e 100644
--- a/helix-term/src/ui/editor.rs
+++ b/helix-term/src/ui/editor.rs
@@ -8,7 +8,9 @@ use crate::{
 
 use helix_core::{
     coords_at_pos, encoding,
-    graphemes::{ensure_grapheme_boundary_next, next_grapheme_boundary, prev_grapheme_boundary},
+    graphemes::{
+        ensure_grapheme_boundary_next_byte, next_grapheme_boundary, prev_grapheme_boundary,
+    },
     movement::Direction,
     syntax::{self, HighlightEvent},
     unicode::segmentation::UnicodeSegmentation,
@@ -154,8 +156,8 @@ impl EditorView {
         .map(move |event| match event {
             // convert byte offsets to char offset
             HighlightEvent::Source { start, end } => {
-                let start = ensure_grapheme_boundary_next(text, text.byte_to_char(start));
-                let end = ensure_grapheme_boundary_next(text, text.byte_to_char(end));
+                let start = text.byte_to_char(ensure_grapheme_boundary_next_byte(text, start));
+                let end = text.byte_to_char(ensure_grapheme_boundary_next_byte(text, end));
                 HighlightEvent::Source { start, end }
             }
             event => event,
-- 
cgit v1.2.3-70-g09d2