diff options
Diffstat (limited to 'helix-core/src/selection.rs')
| -rw-r--r-- | helix-core/src/selection.rs | 156 |
1 files changed, 88 insertions, 68 deletions
diff --git a/helix-core/src/selection.rs b/helix-core/src/selection.rs index 4260c002..ebc88f8b 100644 --- a/helix-core/src/selection.rs +++ b/helix-core/src/selection.rs @@ -137,6 +137,27 @@ impl Range { } } + /// Returns a range that encompasses both input ranges. + /// + /// This is like `extend()`, but tries to negotiate the + /// anchor/head ordering between the two input ranges. + #[must_use] + pub fn merge(&self, other: Self) -> Self { + if self.anchor > self.head && other.anchor > other.head { + Range { + anchor: self.anchor.max(other.anchor), + head: self.head.min(other.head), + horiz: None, + } + } else { + Range { + anchor: self.from().min(other.from()), + head: self.to().max(other.to()), + horiz: None, + } + } + } + /// Compute a possibly new range from this range, attempting to ensure /// a minimum range width of 1 char by shifting the head in the forward /// direction as needed. @@ -170,19 +191,20 @@ impl Range { /// ranges will never collapse to zero-width. #[must_use] pub fn grapheme_aligned(&self, slice: RopeSlice) -> Self { - let (new_anchor, new_head) = if self.anchor == self.head { - let pos = ensure_grapheme_boundary_prev(slice, self.anchor); - (pos, pos) - } else if self.anchor < self.head { - ( + use std::cmp::Ordering; + let (new_anchor, new_head) = match self.anchor.cmp(&self.head) { + Ordering::Equal => { + let pos = ensure_grapheme_boundary_prev(slice, self.anchor); + (pos, pos) + } + Ordering::Less => ( ensure_grapheme_boundary_prev(slice, self.anchor), ensure_grapheme_boundary_next(slice, self.head), - ) - } else { - ( + ), + Ordering::Greater => ( ensure_grapheme_boundary_next(slice, self.anchor), ensure_grapheme_boundary_prev(slice, self.head), - ) + ), }; Range { anchor: new_anchor, @@ -238,10 +260,8 @@ impl Selection { } pub fn push(mut self, range: Range) -> Self { - let index = self.ranges.len(); self.ranges.push(range); - - Self::normalize(self.ranges, index) + self.normalized() } // replace_range @@ -287,80 +307,80 @@ impl Selection { Self::single(pos, pos) } - fn normalize(mut ranges: SmallVec<[Range; 1]>, mut primary_index: usize) -> Self { - let primary = ranges[primary_index]; - ranges.sort_unstable_by_key(Range::from); - primary_index = ranges.iter().position(|&range| range == primary).unwrap(); - - let mut result = SmallVec::with_capacity(ranges.len()); // approx - - // TODO: we could do with one vec by removing elements as we mutate - - let mut i = 0; - - for range in ranges.into_iter() { - // if previous value exists - if let Some(prev) = result.last_mut() { - // and we overlap it - - // TODO: we used to simply check range.from() <(=) prev.to() - // avoiding two comparisons - if range.overlaps(prev) { - let from = prev.from(); - let to = std::cmp::max(range.to(), prev.to()); - - if i <= primary_index { - primary_index -= 1 - } - - // merge into previous - if range.anchor > range.head { - prev.anchor = to; - prev.head = from; - } else { - prev.anchor = from; - prev.head = to; - } - continue; + /// Normalizes a `Selection`. + pub fn normalize(&mut self) -> &mut Self { + let primary = self.ranges[self.primary_index]; + self.ranges.sort_unstable_by_key(Range::from); + self.primary_index = self + .ranges + .iter() + .position(|&range| range == primary) + .unwrap(); + + let mut prev_i = 0; + for i in 1..self.ranges.len() { + if self.ranges[prev_i].overlaps(&self.ranges[i]) { + if i == self.primary_index { + self.primary_index = prev_i; } + self.ranges[prev_i] = self.ranges[prev_i].merge(self.ranges[i]); + } else { + prev_i += 1; + self.ranges[prev_i] = self.ranges[i]; } - - result.push(range); - i += 1 } - Self { - ranges: result, - primary_index, - } + self.ranges.truncate(prev_i + 1); + + self + } + + /// Normalizes a `Selection`. + #[must_use] + pub fn normalized(mut self) -> Self { + self.normalize(); + self } // TODO: consume an iterator or a vec to reduce allocations? #[must_use] pub fn new(ranges: SmallVec<[Range; 1]>, primary_index: usize) -> Self { assert!(!ranges.is_empty()); + debug_assert!(primary_index < ranges.len()); - // fast path for a single selection (cursor) - if ranges.len() == 1 { - return Self { - ranges, - primary_index: 0, - }; + let mut selection = Self { + ranges, + primary_index, + }; + + if selection.ranges.len() > 1 { + // TODO: only normalize if needed (any ranges out of order) + selection.normalize(); } - // TODO: only normalize if needed (any ranges out of order) - Self::normalize(ranges, primary_index) + selection } - /// Takes a closure and maps each selection over the closure. - pub fn transform<F>(&self, f: F) -> Self + /// Takes a closure and maps each `Range` over the closure. + pub fn transform<F>(&mut self, f: F) -> &mut Self where F: Fn(Range) -> Range, { - Self::new( - self.ranges.iter().copied().map(f).collect(), - self.primary_index, - ) + for range in self.ranges.iter_mut() { + *range = f(*range) + } + + self + } + + /// Takes a closure and maps each `Range` over the closure. + #[must_use] + pub fn transformed<F>(mut self, f: F) -> Self + where + F: Fn(Range) -> Range, + { + self.transform(f); + self } pub fn fragments<'a>(&'a self, text: RopeSlice<'a>) -> impl Iterator<Item = Cow<str>> + 'a { |