From 0883b4fae03343978e61fc377775d7ba93f86b40 Mon Sep 17 00:00:00 2001 From: Nathan Vegdahl Date: Mon, 26 Jul 2021 08:40:30 -0700 Subject: Collect some common patterns into methods on `Range`. --- helix-core/src/movement.rs | 50 ++++++--------------------- helix-core/src/selection.rs | 80 +++++++++++++++++++------------------------- helix-core/src/textobject.rs | 15 +++------ 3 files changed, 51 insertions(+), 94 deletions(-) (limited to 'helix-core/src') diff --git a/helix-core/src/movement.rs b/helix-core/src/movement.rs index 80d19501..4af82a1d 100644 --- a/helix-core/src/movement.rs +++ b/helix-core/src/movement.rs @@ -31,15 +31,7 @@ pub fn move_horizontally( count: usize, behaviour: Movement, ) -> Range { - use Movement::Extend; - - // Shift back one grapheme if needed, to account for - // the cursor being visually 1-width. - let pos = if range.head > range.anchor { - prev_grapheme_boundary(slice, range.head) - } else { - range.head - }; + let pos = range.cursor(slice); // Compute the new position. let new_pos = if dir == Direction::Backward { @@ -49,11 +41,7 @@ pub fn move_horizontally( }; // Compute the final new range. - if behaviour == Extend { - range.move_head(slice, new_pos, true) - } else { - Range::point(new_pos) - } + range.put_cursor(slice, new_pos, behaviour == Movement::Extend) } pub fn move_vertically( @@ -63,13 +51,7 @@ pub fn move_vertically( count: usize, behaviour: Movement, ) -> Range { - // Shift back one grapheme if needed, to account for - // the cursor being visually 1-width. - let pos = if range.head > range.anchor { - prev_grapheme_boundary(slice, range.head) - } else { - range.head - }; + let pos = range.cursor(slice); // Compute the current position's 2d coordinates. let Position { row, col } = coords_at_pos(slice, pos); @@ -89,24 +71,14 @@ pub fn move_vertically( ) }; - // Compute the new range according to the type of movement. - match behaviour { - Movement::Move => Range { - anchor: new_pos, - head: new_pos, - horiz: Some(horiz), - }, - - Movement::Extend => { - if slice.line(new_row).len_chars() > 0 { - let mut new_range = range.move_head(slice, new_pos, true); - new_range.horiz = Some(horiz); - new_range - } else { - range - } - } + // Special-case to avoid moving to the end of the last non-empty line. + if behaviour == Movement::Extend && slice.line(new_row).len_chars() == 0 { + return range; } + + let mut new_range = range.put_cursor(slice, new_pos, behaviour == Movement::Extend); + new_range.horiz = Some(horiz); + new_range } pub fn move_next_word_start(slice: RopeSlice, range: Range, count: usize) -> Range { @@ -153,7 +125,7 @@ fn word_move(slice: RopeSlice, range: Range, count: usize, target: WordMotionTar // Prepare the range appropriately based on the target movement // direction. This is addressing two things at once: // - // 1. 1-width range sementics. + // 1. Block-cursor semantics. // 2. The anchor position being irrelevant to the output result. #[allow(clippy::collapsible_else_if)] // Makes the structure clearer in this case. let start_range = if is_prev { diff --git a/helix-core/src/selection.rs b/helix-core/src/selection.rs index cef68212..247a69fe 100644 --- a/helix-core/src/selection.rs +++ b/helix-core/src/selection.rs @@ -73,16 +73,11 @@ impl Range { std::cmp::max(self.anchor, self.head) } - /// The line number that the head is on (using 1-width semantics). + /// The line number that the block-cursor is on. #[inline] #[must_use] - pub fn head_line(&self, text: RopeSlice) -> usize { - let head = if self.anchor < self.head { - prev_grapheme_boundary(text, self.head) - } else { - self.head - }; - text.char_to_line(head) + pub fn cursor_line(&self, text: RopeSlice) -> usize { + text.char_to_line(self.cursor(text)) } /// The (inclusive) range of lines that the range overlaps. @@ -248,29 +243,44 @@ impl Range { } } - /// Moves the head of the `Range` to `char_idx`, adjusting the anchor - /// as needed to preserve 1-width range semantics. + /// Gets the left-side position of the block cursor. + #[must_use] + #[inline] + pub fn cursor(self, text: RopeSlice) -> usize { + if self.head > self.anchor { + prev_grapheme_boundary(text, self.head) + } else { + self.head + } + } + + /// Puts the left side of the block cursor at `char_idx`, optionally extending. /// - /// `block_cursor` specifies whether it should treat `char_idx` as a block - /// cursor position or as a range-end position. + /// This follows "1-width" semantics, and therefore does a combination of anchor + /// and head moves to behave as if both the front and back of the range are 1-width + /// blocks /// /// This method assumes that the range and `char_idx` are already properly /// grapheme-aligned. #[must_use] #[inline] - pub fn move_head(self, text: RopeSlice, char_idx: usize, block_cursor: bool) -> Range { - let anchor = if self.head >= self.anchor && char_idx < self.anchor { - next_grapheme_boundary(text, self.anchor) - } else if self.head < self.anchor && char_idx >= self.anchor { - prev_grapheme_boundary(text, self.anchor) - } else { - self.anchor - }; + pub fn put_cursor(self, text: RopeSlice, char_idx: usize, extend: bool) -> Range { + if extend { + let anchor = if self.head >= self.anchor && char_idx < self.anchor { + next_grapheme_boundary(text, self.anchor) + } else if self.head < self.anchor && char_idx >= self.anchor { + prev_grapheme_boundary(text, self.anchor) + } else { + self.anchor + }; - if block_cursor && anchor <= char_idx { - Range::new(anchor, next_grapheme_boundary(text, char_idx)) + if anchor <= char_idx { + Range::new(anchor, next_grapheme_boundary(text, char_idx)) + } else { + Range::new(anchor, char_idx) + } } else { - Range::new(anchor, char_idx) + Range::point(char_idx) } } @@ -309,18 +319,6 @@ impl Selection { self.ranges[self.primary_index] } - #[must_use] - pub fn cursor(&self, text: RopeSlice) -> usize { - let range = self.primary(); - - // For 1-width cursor semantics. - if range.anchor < range.head { - prev_grapheme_boundary(text, range.head).max(range.anchor) - } else { - range.head - } - } - /// Ensure selection containing only the primary selection. pub fn into_single(self) -> Self { if self.ranges.len() == 1 { @@ -452,17 +450,9 @@ impl Selection { } /// Transforms the selection into all of the left-side head positions, - /// using 1-width semantics. + /// using block-cursor semantics. pub fn cursors(self, text: RopeSlice) -> Self { - self.transform(|range| { - // For 1-width cursor semantics. - let pos = if range.anchor < range.head { - prev_grapheme_boundary(text, range.head).max(range.anchor) - } else { - range.head - }; - Range::new(pos, pos) - }) + self.transform(|range| Range::point(range.cursor(text))) } pub fn fragments<'a>(&'a self, text: RopeSlice<'a>) -> impl Iterator> + 'a { diff --git a/helix-core/src/textobject.rs b/helix-core/src/textobject.rs index ae18d7cf..e011c912 100644 --- a/helix-core/src/textobject.rs +++ b/helix-core/src/textobject.rs @@ -59,17 +59,12 @@ pub fn textobject_word( textobject: TextObject, _count: usize, ) -> Range { - // For 1-width cursor semantics. - let head = if range.head > range.anchor { - prev_grapheme_boundary(slice, range.head) - } else { - range.head - }; + let pos = range.cursor(slice); - let word_start = find_word_boundary(slice, head, Direction::Backward); - let word_end = match slice.get_char(head).map(categorize_char) { - None | Some(CharCategory::Whitespace | CharCategory::Eol) => head, - _ => find_word_boundary(slice, head + 1, Direction::Forward), + let word_start = find_word_boundary(slice, pos, Direction::Backward); + let word_end = match slice.get_char(pos).map(categorize_char) { + None | Some(CharCategory::Whitespace | CharCategory::Eol) => pos, + _ => find_word_boundary(slice, pos + 1, Direction::Forward), }; // Special case. -- cgit v1.2.3-70-g09d2