@@ -2,79 +2,76 @@ use std::mem;
type Edit = buffer::Edit<u32>;
-#[derive(Default, Debug)]
+#[derive(Default, Debug, PartialEq, Eq)]
struct Patch(Vec<Edit>);
impl Patch {
fn compose(&self, new: &Self) -> Patch {
- let mut composed = Vec::new();
+ let mut composed = Vec::<Edit>::new();
let mut old_edits = self.0.iter().cloned().peekable();
let mut old_delta = 0;
let mut new_delta = 0;
+ let mut intermediate_start;
+ let mut intermediate_end = 0;
for mut new_edit in new.0.iter().cloned() {
- while let Some(mut old_edit) = old_edits.peek().cloned() {
- if old_edit.new.end < new_edit.old.start {
+ let new_edit_delta = new_edit.new.len() as i32 - new_edit.old.len() as i32;
+
+ if let Some(last_edit) = composed.last_mut() {
+ if intermediate_end >= new_edit.old.start {
+ if new_edit.old.end > intermediate_end {
+ last_edit.old.end += new_edit.old.end - intermediate_end;
+ last_edit.new.end += new_edit.old.end - intermediate_end;
+ intermediate_end = new_edit.old.end;
+ }
+ last_edit.new.end = (last_edit.new.end as i32 + new_edit_delta) as u32;
+ continue;
+ }
+ }
+
+ intermediate_start = new_edit.old.start;
+ intermediate_end = new_edit.old.end;
+ new_edit.old.start = (new_edit.old.start as i32 - old_delta) as u32;
+ new_edit.old.end = (new_edit.old.end as i32 - old_delta) as u32;
+
+ while let Some(old_edit) = old_edits.peek() {
+ let old_edit_delta = old_edit.new.len() as i32 - old_edit.old.len() as i32;
+
+ if old_edit.new.end < intermediate_start {
+ let mut old_edit = old_edit.clone();
old_edit.new.start = (old_edit.new.start as i32 + new_delta) as u32;
old_edit.new.end = (old_edit.new.end as i32 + new_delta) as u32;
- old_edits.next();
+ new_edit.old.start = (new_edit.old.start as i32 - old_edit_delta) as u32;
+ new_edit.old.end = (new_edit.old.end as i32 - old_edit_delta) as u32;
composed.push(old_edit);
- } else if old_edit.new.start < new_edit.old.end {
- if old_edit.new.start < new_edit.old.start {
- new_edit.old.start -= new_edit.old.start - old_edit.new.start;
- new_edit.new.start -= new_edit.old.start - old_edit.new.start;
+ } else if old_edit.new.start <= intermediate_end {
+ if old_edit.new.start < intermediate_start {
+ new_edit.new.start -= intermediate_start - old_edit.new.start;
+ new_edit.old.start -= intermediate_start - old_edit.new.start;
}
- if old_edit.new.end > new_edit.old.end {
- new_edit.old.end += old_edit.new.end - new_edit.old.end;
- new_edit.new.end += old_edit.new.end - new_edit.old.end;
+ if old_edit.new.end > intermediate_end {
+ new_edit.new.end += old_edit.new.end - intermediate_end;
+ new_edit.old.end += old_edit.new.end - intermediate_end;
+ intermediate_end = old_edit.new.end;
}
+ new_edit.old.end = (new_edit.old.end as i32 - old_edit_delta) as u32;
+ } else {
+ break;
}
+
+ old_delta += old_edit_delta;
+ old_edits.next();
}
+
+ new_delta += new_edit_delta;
+ composed.push(new_edit);
}
- todo!();
- // for mut old_edit in self.0.iter().cloned() {
- // let old_edit_new_start = old_edit.new.start;
- // let old_edit_new_end = old_edit.new.end;
- // let mut next_new_delta = new_delta;
- // while let Some(mut new_edit) = new_edits.peek().cloned() {
- // let new_edit_delta = new_edit.new.len() as i32 - new_edit.old.len() as i32;
- // if new_edit.old.end < old_edit_new_start {
- // new_edit.old.start = (new_edit.old.start as i32 - old_delta) as u32;
- // new_edit.old.end = (new_edit.old.end as i32 - old_delta) as u32;
- // new_edits.next();
- // new_delta += new_edit_delta;
- // next_new_delta += new_edit_delta;
- // composed.push(new_edit);
- // } else if new_edit.old.start <= old_edit_new_end {
- // if new_edit.old.start < old_edit_new_start {
- // old_edit.old.start -= old_edit_new_start - new_edit.old.start;
- // old_edit.new.start -= old_edit_new_start - new_edit.old.start;
- // }
- // if new_edit.old.end > old_edit_new_end {
- // old_edit.old.end += new_edit.old.end - old_edit_new_end;
- // old_edit.new.end += new_edit.old.end - old_edit_new_end;
- // }
-
- // old_edit.new.end = (old_edit.new.end as i32 + new_edit_delta) as u32;
- // new_edits.next();
- // next_new_delta += new_edit_delta;
- // } else {
- // break;
- // }
- // }
-
- // old_edit.new.start = (old_edit.new.start as i32 + new_delta) as u32;
- // old_edit.new.end = (old_edit.new.end as i32 + new_delta) as u32;
- // old_delta += old_edit.new.len() as i32 - old_edit.old.len() as i32;
- // new_delta = next_new_delta;
- // composed.push(old_edit);
- // }
- // composed.extend(new_edits.map(|mut new_edit| {
- // new_edit.old.start = (new_edit.old.start as i32 - old_delta) as u32;
- // new_edit.old.end = (new_edit.old.end as i32 - old_delta) as u32;
- // new_edit
- // }));
+ while let Some(mut old_edit) = old_edits.next() {
+ old_edit.new.start = (old_edit.new.start as i32 + new_delta) as u32;
+ old_edit.new.end = (old_edit.new.end as i32 + new_delta) as u32;
+ composed.push(old_edit);
+ }
Patch(composed)
}
@@ -93,6 +90,171 @@ mod tests {
use rand::prelude::*;
use std::env;
+ #[gpui::test]
+ fn test_one_disjoint_edit() {
+ assert_patch_composition(
+ Patch(vec![Edit {
+ old: 1..3,
+ new: 1..4,
+ }]),
+ Patch(vec![Edit {
+ old: 0..0,
+ new: 0..4,
+ }]),
+ Patch(vec![
+ Edit {
+ old: 0..0,
+ new: 0..4,
+ },
+ Edit {
+ old: 1..3,
+ new: 5..8,
+ },
+ ]),
+ );
+
+ assert_patch_composition(
+ Patch(vec![Edit {
+ old: 1..3,
+ new: 1..4,
+ }]),
+ Patch(vec![Edit {
+ old: 5..9,
+ new: 5..7,
+ }]),
+ Patch(vec![
+ Edit {
+ old: 1..3,
+ new: 1..4,
+ },
+ Edit {
+ old: 4..8,
+ new: 5..7,
+ },
+ ]),
+ );
+ }
+
+ #[gpui::test]
+ fn test_one_overlapping_edit() {
+ assert_patch_composition(
+ Patch(vec![Edit {
+ old: 1..3,
+ new: 1..4,
+ }]),
+ Patch(vec![Edit {
+ old: 3..5,
+ new: 3..6,
+ }]),
+ Patch(vec![Edit {
+ old: 1..4,
+ new: 1..6,
+ }]),
+ );
+ }
+
+ #[gpui::test]
+ fn test_two_disjoint_and_overlapping() {
+ assert_patch_composition(
+ Patch(vec![
+ Edit {
+ old: 1..3,
+ new: 1..4,
+ },
+ Edit {
+ old: 8..12,
+ new: 9..11,
+ },
+ ]),
+ Patch(vec![
+ Edit {
+ old: 0..0,
+ new: 0..4,
+ },
+ Edit {
+ old: 3..10,
+ new: 7..9,
+ },
+ ]),
+ Patch(vec![
+ Edit {
+ old: 0..0,
+ new: 0..4,
+ },
+ Edit {
+ old: 1..12,
+ new: 5..10,
+ },
+ ]),
+ );
+ }
+
+ #[gpui::test]
+ fn test_two_new_edits_overlapping_one_old_edit() {
+ assert_patch_composition(
+ Patch(vec![Edit {
+ old: 0..0,
+ new: 0..3,
+ }]),
+ Patch(vec![
+ Edit {
+ old: 0..0,
+ new: 0..1,
+ },
+ Edit {
+ old: 1..2,
+ new: 2..2,
+ },
+ ]),
+ Patch(vec![Edit {
+ old: 0..0,
+ new: 0..3,
+ }]),
+ );
+
+ assert_patch_composition(
+ Patch(vec![Edit {
+ old: 2..3,
+ new: 2..4,
+ }]),
+ Patch(vec![
+ Edit {
+ old: 0..2,
+ new: 0..1,
+ },
+ Edit {
+ old: 3..3,
+ new: 2..5,
+ },
+ ]),
+ Patch(vec![Edit {
+ old: 0..3,
+ new: 0..6,
+ }]),
+ );
+
+ assert_patch_composition(
+ Patch(vec![Edit {
+ old: 0..0,
+ new: 0..2,
+ }]),
+ Patch(vec![
+ Edit {
+ old: 0..0,
+ new: 0..2,
+ },
+ Edit {
+ old: 2..5,
+ new: 4..4,
+ },
+ ]),
+ Patch(vec![Edit {
+ old: 0..3,
+ new: 0..4,
+ }]),
+ );
+ }
+
#[gpui::test(iterations = 1000, seed = 131)]
fn test_random(mut rng: StdRng) {
let operations = env::var("OPERATIONS")
@@ -159,4 +321,35 @@ mod tests {
assert_eq!(chars, final_chars);
}
+
+ #[track_caller]
+ fn assert_patch_composition(old: Patch, new: Patch, composed: Patch) {
+ let original = ('a'..'z').collect::<Vec<_>>();
+ let inserted = ('A'..'Z').collect::<Vec<_>>();
+
+ let mut expected = original.clone();
+ apply_patch(&mut expected, &old, &inserted);
+ apply_patch(&mut expected, &new, &inserted);
+
+ let mut actual = original.clone();
+ apply_patch(&mut actual, &composed, &expected);
+ assert_eq!(
+ actual.into_iter().collect::<String>(),
+ expected.into_iter().collect::<String>(),
+ "expected patch is incorrect"
+ );
+
+ assert_eq!(old.compose(&new), composed);
+ }
+
+ fn apply_patch(text: &mut Vec<char>, patch: &Patch, new_text: &[char]) {
+ for edit in patch.0.iter().rev() {
+ text.splice(
+ edit.old.start as usize..edit.old.end as usize,
+ new_text[edit.new.start as usize..edit.new.end as usize]
+ .iter()
+ .copied(),
+ );
+ }
+ }
}