aboutsummaryrefslogtreecommitdiff
path: root/helix-core/src/selection.rs
diff options
context:
space:
mode:
Diffstat (limited to 'helix-core/src/selection.rs')
-rw-r--r--helix-core/src/selection.rs95
1 files changed, 61 insertions, 34 deletions
diff --git a/helix-core/src/selection.rs b/helix-core/src/selection.rs
index 9e366c33..0539c9f6 100644
--- a/helix-core/src/selection.rs
+++ b/helix-core/src/selection.rs
@@ -161,34 +161,35 @@ impl Range {
self.from() <= pos && pos < self.to()
}
- /// Map a range through a set of changes. Returns a new range representing the same position
- /// after the changes are applied.
- pub fn map(self, changes: &ChangeSet) -> Self {
+ /// Map a range through a set of changes. Returns a new range representing
+ /// the same position after the changes are applied. Note that this
+ /// function runs in O(N) (N is number of changes) and can therefore
+ /// cause performance problems if run for a large number of ranges as the
+ /// complexity is then O(MN) (for multicuror M=N usually). Instead use
+ /// [Selection::map] or [ChangeSet::update_positions] instead
+ pub fn map(mut self, changes: &ChangeSet) -> Self {
use std::cmp::Ordering;
- let (anchor, head) = match self.anchor.cmp(&self.head) {
- Ordering::Equal => (
- changes.map_pos(self.anchor, Assoc::After),
- changes.map_pos(self.head, Assoc::After),
- ),
- Ordering::Less => (
- changes.map_pos(self.anchor, Assoc::After),
- changes.map_pos(self.head, Assoc::Before),
- ),
- Ordering::Greater => (
- changes.map_pos(self.anchor, Assoc::Before),
- changes.map_pos(self.head, Assoc::After),
- ),
- };
-
- // We want to return a new `Range` with `horiz == None` every time,
- // even if the anchor and head haven't changed, because we don't
- // know if the *visual* position hasn't changed due to
- // character-width or grapheme changes earlier in the text.
- Self {
- anchor,
- head,
- old_visual_position: None,
+ if changes.is_empty() {
+ return self;
}
+
+ let positions_to_map = match self.anchor.cmp(&self.head) {
+ Ordering::Equal => [
+ (&mut self.anchor, Assoc::After),
+ (&mut self.head, Assoc::After),
+ ],
+ Ordering::Less => [
+ (&mut self.anchor, Assoc::After),
+ (&mut self.head, Assoc::Before),
+ ],
+ Ordering::Greater => [
+ (&mut self.head, Assoc::After),
+ (&mut self.anchor, Assoc::Before),
+ ],
+ };
+ changes.update_positions(positions_to_map.into_iter());
+ self.old_visual_position = None;
+ self
}
/// Extend the range to cover at least `from` `to`.
@@ -450,18 +451,44 @@ impl Selection {
/// Map selections over a set of changes. Useful for adjusting the selection position after
/// applying changes to a document.
- pub fn map(self, changes: &ChangeSet) -> Self {
+ pub fn map(mut self, changes: &ChangeSet) -> Self {
if changes.is_empty() {
return self;
}
+ self = self.map_no_normalize(changes);
+ // TODO: only normalize if needed (any ranges out of order)
+ self = self.normalize();
- Self::new(
- self.ranges
- .into_iter()
- .map(|range| range.map(changes))
- .collect(),
- self.primary_index,
- )
+ self
+ }
+
+ /// Map selections over a set of changes. Useful for adjusting the selection position after
+ /// applying changes to a document. Doesn't normalize the selection
+ pub fn map_no_normalize(mut self, changes: &ChangeSet) -> Self {
+ if changes.is_empty() {
+ return self;
+ }
+
+ let positions_to_map = self.ranges.iter_mut().flat_map(|range| {
+ use std::cmp::Ordering;
+ range.old_visual_position = None;
+ match range.anchor.cmp(&range.head) {
+ Ordering::Equal => [
+ (&mut range.anchor, Assoc::After),
+ (&mut range.head, Assoc::After),
+ ],
+ Ordering::Less => [
+ (&mut range.anchor, Assoc::After),
+ (&mut range.head, Assoc::Before),
+ ],
+ Ordering::Greater => [
+ (&mut range.head, Assoc::After),
+ (&mut range.anchor, Assoc::Before),
+ ],
+ }
+ });
+ changes.update_positions(positions_to_map);
+ self
}
pub fn ranges(&self) -> &[Range] {