fix panic when deleting overlapping ranges

Some deletion operations (especially those that use indentation)
can generate overlapping deletion ranges when using multiple cursors.
To fix that problem a new `Transaction::delete` and
`Transaction:delete_by_selection` function were added. These functions
merge overlapping deletion ranges instead of generating an invalid
transaction. This merging of changes is only possible for deletions
and not for other changes and therefore require its own function.

The function has been used in all commands that currently delete
text by using `Transaction::change_by_selection`.
This commit is contained in:
Pascal Kuthe 2023-02-16 22:15:06 +01:00 committed by Blaž Hrastnik
parent 6842fd4c36
commit f8225ed921
4 changed files with 102 additions and 27 deletions

View File

@ -67,4 +67,4 @@ pub fn find_first_non_whitespace_char(line: RopeSlice) -> Option<usize> {
pub use diagnostic::Diagnostic;
pub use line_ending::{LineEnding, DEFAULT_LINE_ENDING};
pub use transaction::{Assoc, Change, ChangeSet, Operation, Transaction};
pub use transaction::{Assoc, Change, ChangeSet, Deletion, Operation, Transaction};

View File

@ -5,6 +5,7 @@
/// (from, to, replacement)
pub type Change = (usize, usize, Option<Tendril>);
pub type Deletion = (usize, usize);
// TODO: pub(crate)
#[derive(Debug, Clone, PartialEq, Eq)]
@ -534,6 +535,41 @@ pub fn change<I>(doc: &Rope, changes: I) -> Self
Self::from(changeset)
}
/// Generate a transaction from a set of potentially overlapping deletions
/// by merging overlapping deletions together.
pub fn delete<I>(doc: &Rope, deletions: I) -> Self
where
I: Iterator<Item = Deletion>,
{
let len = doc.len_chars();
let (lower, upper) = deletions.size_hint();
let size = upper.unwrap_or(lower);
let mut changeset = ChangeSet::with_capacity(2 * size + 1); // rough estimate
let mut last = 0;
for (mut from, to) in deletions {
if last > to {
continue;
}
if last > from {
from = last
}
debug_assert!(
from <= to,
"Edit end must end before it starts (should {from} <= {to})"
);
// Retain from last "to" to current "from"
changeset.retain(from - last);
changeset.delete(to - from);
last = to;
}
changeset.retain(len - last);
Self::from(changeset)
}
/// Generate a transaction with a change per selection range.
pub fn change_by_selection<F>(doc: &Rope, selection: &Selection, f: F) -> Self
where
@ -580,6 +616,16 @@ pub fn change_by_selection_ignore_overlapping(
)
}
/// Generate a transaction with a deletion per selection range.
/// Compared to using `change_by_selection` directly these ranges may overlap.
/// In that case they are merged
pub fn delete_by_selection<F>(doc: &Rope, selection: &Selection, f: F) -> Self
where
F: FnMut(&Range) -> Deletion,
{
Self::delete(doc, selection.iter().map(f))
}
/// Insert text at each selection head.
pub fn insert(doc: &Rope, selection: &Selection, text: Tendril) -> Self {
Self::change_by_selection(doc, selection, |range| {

View File

@ -2315,9 +2315,8 @@ fn delete_selection_impl(cx: &mut Context, op: Operation) {
};
// then delete
let transaction = Transaction::change_by_selection(doc.text(), selection, |range| {
(range.from(), range.to(), None)
});
let transaction =
Transaction::delete_by_selection(doc.text(), selection, |range| (range.from(), range.to()));
doc.apply(&transaction, view.id);
match op {
@ -2333,9 +2332,8 @@ fn delete_selection_impl(cx: &mut Context, op: Operation) {
#[inline]
fn delete_selection_insert_mode(doc: &mut Document, view: &mut View, selection: &Selection) {
let transaction = Transaction::change_by_selection(doc.text(), selection, |range| {
(range.from(), range.to(), None)
});
let transaction =
Transaction::delete_by_selection(doc.text(), selection, |range| (range.from(), range.to()));
doc.apply(&transaction, view.id);
}
@ -3422,10 +3420,10 @@ pub fn delete_char_backward(cx: &mut Context) {
let auto_pairs = doc.auto_pairs(cx.editor);
let transaction =
Transaction::change_by_selection(doc.text(), doc.selection(view.id), |range| {
Transaction::delete_by_selection(doc.text(), doc.selection(view.id), |range| {
let pos = range.cursor(text);
if pos == 0 {
return (pos, pos, None);
return (pos, pos);
}
let line_start_pos = text.line_to_char(range.cursor_line(text));
// consider to delete by indent level if all characters before `pos` are indent units.
@ -3433,11 +3431,7 @@ pub fn delete_char_backward(cx: &mut Context) {
if !fragment.is_empty() && fragment.chars().all(|ch| ch == ' ' || ch == '\t') {
if text.get_char(pos.saturating_sub(1)) == Some('\t') {
// fast path, delete one char
(
graphemes::nth_prev_grapheme_boundary(text, pos, 1),
pos,
None,
)
(graphemes::nth_prev_grapheme_boundary(text, pos, 1), pos)
} else {
let width: usize = fragment
.chars()
@ -3464,7 +3458,7 @@ pub fn delete_char_backward(cx: &mut Context) {
_ => break,
}
}
(start, pos, None) // delete!
(start, pos) // delete!
}
} else {
match (
@ -3482,17 +3476,12 @@ pub fn delete_char_backward(cx: &mut Context) {
(
graphemes::nth_prev_grapheme_boundary(text, pos, count),
graphemes::nth_next_grapheme_boundary(text, pos, count),
None,
)
}
_ =>
// delete 1 char
{
(
graphemes::nth_prev_grapheme_boundary(text, pos, count),
pos,
None,
)
(graphemes::nth_prev_grapheme_boundary(text, pos, count), pos)
}
}
}
@ -3508,13 +3497,9 @@ pub fn delete_char_forward(cx: &mut Context) {
let (view, doc) = current!(cx.editor);
let text = doc.text().slice(..);
let transaction =
Transaction::change_by_selection(doc.text(), doc.selection(view.id), |range| {
Transaction::delete_by_selection(doc.text(), doc.selection(view.id), |range| {
let pos = range.cursor(text);
(
pos,
graphemes::nth_next_grapheme_boundary(text, pos, count),
None,
)
(pos, graphemes::nth_next_grapheme_boundary(text, pos, count))
});
doc.apply(&transaction, view.id);

View File

@ -385,3 +385,47 @@ async fn test_character_info() -> anyhow::Result<()> {
Ok(())
}
#[tokio::test(flavor = "multi_thread")]
async fn test_delete_char_backward() -> anyhow::Result<()> {
// don't panic when deleting overlapping ranges
test((
platform_line("#(x|)# #[x|]#").as_str(),
"c<space><backspace><esc>",
platform_line("#[\n|]#").as_str(),
))
.await?;
test((
platform_line("#( |)##( |)#a#( |)#axx#[x|]#a").as_str(),
"li<backspace><esc>",
platform_line("#(a|)##(|a)#xx#[|a]#").as_str(),
))
.await?;
Ok(())
}
#[tokio::test(flavor = "multi_thread")]
async fn test_delete_word_backward() -> anyhow::Result<()> {
// don't panic when deleting overlapping ranges
test((
platform_line("fo#[o|]#ba#(r|)#").as_str(),
"a<C-w><esc>",
platform_line("#[\n|]#").as_str(),
))
.await?;
Ok(())
}
#[tokio::test(flavor = "multi_thread")]
async fn test_delete_word_forward() -> anyhow::Result<()> {
// don't panic when deleting overlapping ranges
test((
platform_line("fo#[o|]#b#(|ar)#").as_str(),
"i<A-d><esc>",
platform_line("fo#[\n|]#").as_str(),
))
.await?;
Ok(())
}