diff options
| -rw-r--r-- | helix-core/src/position.rs | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/helix-core/src/position.rs b/helix-core/src/position.rs index 611e6b76..08a8aed5 100644 --- a/helix-core/src/position.rs +++ b/helix-core/src/position.rs @@ -71,18 +71,27 @@ pub fn coords_at_pos(text: RopeSlice, pos: usize) -> Position { /// Convert (line, column) coordinates to a character index. /// -/// `is_1_width` specifies whether the position should be treated -/// as a block cursor or not. This effects how line-ends are handled. -/// `false` corresponds to properly round-tripping with `coords_at_pos()`, -/// whereas `true` will ensure that block cursors don't jump off the -/// end of the line. +/// If the `line` coordinate is beyond the end of the file, the EOF +/// position will be returned. +/// +/// If the `column` coordinate is past the end of the given line, the +/// line-end position will be returned. What constitutes the "line-end +/// position" depends on the parameter `limit_before_line_ending`. If it's +/// `true`, the line-end position will be just *before* the line ending +/// character. If `false` it will be just *after* the line ending +/// character--on the border between the current line and the next. +/// +/// Usually you only want `limit_before_line_ending` to be `true` if you're working +/// with left-side block-cursor positions, as this prevents the the block cursor +/// from jumping to the next line. Otherwise you typically want it to be `false`, +/// such as when dealing with raw anchor/head positions. /// /// TODO: this should be changed to work in terms of visual row/column, not /// graphemes. -pub fn pos_at_coords(text: RopeSlice, coords: Position, is_1_width: bool) -> usize { +pub fn pos_at_coords(text: RopeSlice, coords: Position, limit_before_line_ending: bool) -> usize { let Position { row, col } = coords; let line_start = text.line_to_char(row); - let line_end = if is_1_width { + let line_end = if limit_before_line_ending { line_end_char_index(&text, row) } else { text.line_to_char((row + 1).min(text.len_lines())) |