diff options
| -rw-r--r-- | helix-core/src/graphemes.rs | 56 | ||||
| -rw-r--r-- | helix-term/src/ui/editor.rs | 8 |
2 files changed, 61 insertions, 3 deletions
diff --git a/helix-core/src/graphemes.rs b/helix-core/src/graphemes.rs index c6398875..a6c74f65 100644 --- a/helix-core/src/graphemes.rs +++ b/helix-core/src/graphemes.rs @@ -120,6 +120,43 @@ pub fn nth_next_grapheme_boundary(slice: RopeSlice, char_idx: usize, n: usize) - chunk_char_idx + tmp } +#[must_use] +pub fn nth_next_grapheme_boundary_byte(slice: RopeSlice, mut byte_idx: usize, n: usize) -> usize { + // Bounds check + debug_assert!(byte_idx <= slice.len_bytes()); + + // Get the chunk with our byte index in it. + let (mut chunk, mut chunk_byte_idx, mut _chunk_char_idx, _) = slice.chunk_at_byte(byte_idx); + + // Set up the grapheme cursor. + let mut gc = GraphemeCursor::new(byte_idx, slice.len_bytes(), true); + + // Find the nth next grapheme cluster boundary. + for _ in 0..n { + loop { + match gc.next_boundary(chunk, chunk_byte_idx) { + Ok(None) => return slice.len_bytes(), + Ok(Some(n)) => { + byte_idx = n; + break; + } + Err(GraphemeIncomplete::NextChunk) => { + chunk_byte_idx += chunk.len(); + let (a, _, _c, _) = slice.chunk_at_byte(chunk_byte_idx); + chunk = a; + // chunk_char_idx = c; + } + Err(GraphemeIncomplete::PreContext(n)) => { + let ctx_chunk = slice.chunk_at_byte(n - 1).0; + gc.provide_context(ctx_chunk, n - ctx_chunk.len()); + } + _ => unreachable!(), + } + } + } + byte_idx +} + /// Finds the next grapheme boundary after the given char position. #[must_use] #[inline(always)] @@ -127,6 +164,13 @@ pub fn next_grapheme_boundary(slice: RopeSlice, char_idx: usize) -> usize { nth_next_grapheme_boundary(slice, char_idx, 1) } +/// Finds the next grapheme boundary after the given byte position. +#[must_use] +#[inline(always)] +pub fn next_grapheme_boundary_byte(slice: RopeSlice, byte_idx: usize) -> usize { + nth_next_grapheme_boundary_byte(slice, byte_idx, 1) +} + /// Returns the passed char index if it's already a grapheme boundary, /// or the next grapheme boundary char index if not. #[must_use] @@ -151,6 +195,18 @@ pub fn ensure_grapheme_boundary_prev(slice: RopeSlice, char_idx: usize) -> usize } } +/// Returns the passed byte index if it's already a grapheme boundary, +/// or the next grapheme boundary byte index if not. +#[must_use] +#[inline] +pub fn ensure_grapheme_boundary_next_byte(slice: RopeSlice, byte_idx: usize) -> usize { + if byte_idx == 0 { + byte_idx + } else { + next_grapheme_boundary_byte(slice, byte_idx - 1) + } +} + /// Returns whether the given char position is a grapheme boundary. #[must_use] pub fn is_grapheme_boundary(slice: RopeSlice, char_idx: usize) -> bool { 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, |