Skip enclosed pairs in surround

Surround operations previously ignored other pairs that are
enclosed within which should be skipped. For example if the
cursor is on the `,` in `{{a},{b}}`, doing `md{` previously
would delete the `{` on the left of `a` and `}` on the right
of `b` instead of the outermost braces. This commit corrects
this behavior.
This commit is contained in:
Gokul Soumya 2021-06-24 00:20:19 +05:30 committed by Blaž Hrastnik
parent fb8e7dc25b
commit 394629ab73

View file

@ -39,13 +39,101 @@ pub fn find_nth_pairs_pos(
n: usize,
) -> Option<(usize, usize)> {
let (open, close) = get_pair(ch);
// find_nth* do not consider current character; +1/-1 to include them
let open_pos = search::find_nth_prev(text, open, pos + 1, n, true)?;
let close_pos = search::find_nth_next(text, close, pos - 1, n, true)?;
let (open_pos, close_pos) = if open == close {
// find_nth* do not consider current character; +1/-1 to include them
(
search::find_nth_prev(text, open, pos + 1, n, true)?,
search::find_nth_next(text, close, pos - 1, n, true)?,
)
} else {
(
find_nth_open_pair(text, open, close, pos, n)?,
find_nth_close_pair(text, open, close, pos, n)?,
)
};
Some((open_pos, close_pos))
}
fn find_nth_open_pair(
text: RopeSlice,
open: char,
close: char,
mut pos: usize,
n: usize,
) -> Option<usize> {
let mut chars = text.chars_at(pos + 1);
// Adjusts pos for the first iteration, and handles the case of the
// cursor being *on* the close character which will get falsely stepped over
// if not skipped here
if chars.prev()? == open {
return Some(pos);
}
for _ in 0..n {
let mut step_over: usize = 0;
loop {
let c = chars.prev()?;
pos = pos.saturating_sub(1);
// ignore other surround pairs that are enclosed *within* our search scope
if c == close {
step_over += 1;
} else if c == open {
if step_over == 0 {
break;
}
step_over = step_over.saturating_sub(1);
}
}
}
Some(pos)
}
fn find_nth_close_pair(
text: RopeSlice,
open: char,
close: char,
mut pos: usize,
n: usize,
) -> Option<usize> {
if pos >= text.len_chars() {
return None;
}
let mut chars = text.chars_at(pos);
if chars.next()? == close {
return Some(pos);
}
for _ in 0..n {
let mut step_over: usize = 0;
loop {
let c = chars.next()?;
pos += 1;
if c == open {
step_over += 1;
} else if c == close {
if step_over == 0 {
break;
}
step_over = step_over.saturating_sub(1);
}
}
}
Some(pos)
}
/// Find position of surround characters around every cursor. Returns None
/// if any positions overlap. Note that the positions are in a flat Vec.
/// Use get_surround_pos().chunks(2) to get matching pairs of surround positions.
@ -101,6 +189,27 @@ mod test {
assert_eq!(find_nth_pairs_pos(slice, '(', 13, 3), Some((0, 27)));
}
#[test]
fn test_find_nth_pairs_pos_same() {
let doc = Rope::from("'so 'many 'good' text' here'");
let slice = doc.slice(..);
// cursor on go[o]d
assert_eq!(find_nth_pairs_pos(slice, '\'', 13, 1), Some((10, 15)));
assert_eq!(find_nth_pairs_pos(slice, '\'', 13, 2), Some((4, 21)));
assert_eq!(find_nth_pairs_pos(slice, '\'', 13, 3), Some((0, 27)));
}
#[test]
fn test_find_nth_pairs_pos_step() {
let doc = Rope::from("((so)((many) good (text))(here))");
let slice = doc.slice(..);
// cursor on go[o]d
assert_eq!(find_nth_pairs_pos(slice, '(', 15, 1), Some((5, 24)));
assert_eq!(find_nth_pairs_pos(slice, '(', 15, 2), Some((0, 31)));
}
#[test]
fn test_find_nth_pairs_pos_mixed() {
let doc = Rope::from("(so [many {good} text] here)");