1mod offset_utf16;
2mod point;
3mod point_utf16;
4mod unclipped;
5
6use arrayvec::ArrayString;
7use smallvec::SmallVec;
8use std::{
9 cmp, fmt, io, mem,
10 ops::{AddAssign, Range},
11 str,
12};
13use sum_tree::{Bias, Dimension, SumTree};
14use unicode_segmentation::GraphemeCursor;
15use util::debug_panic;
16
17pub use offset_utf16::OffsetUtf16;
18pub use point::Point;
19pub use point_utf16::PointUtf16;
20pub use unclipped::Unclipped;
21
22#[cfg(test)]
23const CHUNK_BASE: usize = 6;
24
25#[cfg(not(test))]
26const CHUNK_BASE: usize = 64;
27
28#[derive(Clone, Default)]
29pub struct Rope {
30 chunks: SumTree<Chunk>,
31}
32
33impl Rope {
34 pub fn new() -> Self {
35 Self::default()
36 }
37
38 pub fn append(&mut self, rope: Rope) {
39 let mut chunks = rope.chunks.cursor::<()>();
40 chunks.next(&());
41 if let Some(chunk) = chunks.item() {
42 if self.chunks.last().map_or(false, |c| c.0.len() < CHUNK_BASE)
43 || chunk.0.len() < CHUNK_BASE
44 {
45 self.push(&chunk.0);
46 chunks.next(&());
47 }
48 }
49
50 self.chunks.append(chunks.suffix(&()), &());
51 self.check_invariants();
52 }
53
54 pub fn replace(&mut self, range: Range<usize>, text: &str) {
55 let mut new_rope = Rope::new();
56 let mut cursor = self.cursor(0);
57 new_rope.append(cursor.slice(range.start));
58 cursor.seek_forward(range.end);
59 new_rope.push(text);
60 new_rope.append(cursor.suffix());
61 *self = new_rope;
62 }
63
64 pub fn slice(&self, range: Range<usize>) -> Rope {
65 let mut cursor = self.cursor(0);
66 cursor.seek_forward(range.start);
67 cursor.slice(range.end)
68 }
69
70 pub fn slice_rows(&self, range: Range<u32>) -> Rope {
71 // This would be more efficient with a forward advance after the first, but it's fine.
72 let start = self.point_to_offset(Point::new(range.start, 0));
73 let end = self.point_to_offset(Point::new(range.end, 0));
74 self.slice(start..end)
75 }
76
77 pub fn push(&mut self, mut text: &str) {
78 self.chunks.update_last(
79 |last_chunk| {
80 let split_ix = if last_chunk.0.len() + text.len() <= 2 * CHUNK_BASE {
81 text.len()
82 } else {
83 let mut split_ix =
84 cmp::min(CHUNK_BASE.saturating_sub(last_chunk.0.len()), text.len());
85 while !text.is_char_boundary(split_ix) {
86 split_ix += 1;
87 }
88 split_ix
89 };
90
91 let (suffix, remainder) = text.split_at(split_ix);
92 last_chunk.0.push_str(suffix);
93 text = remainder;
94 },
95 &(),
96 );
97
98 if text.len() > 2048 {
99 return self.push_large(text);
100 }
101 let mut new_chunks = SmallVec::<[_; 16]>::new();
102
103 while !text.is_empty() {
104 let mut split_ix = cmp::min(2 * CHUNK_BASE, text.len());
105 while !text.is_char_boundary(split_ix) {
106 split_ix -= 1;
107 }
108 let (chunk, remainder) = text.split_at(split_ix);
109 new_chunks.push(Chunk(ArrayString::from(chunk).unwrap()));
110 text = remainder;
111 }
112
113 #[cfg(test)]
114 const PARALLEL_THRESHOLD: usize = 4;
115 #[cfg(not(test))]
116 const PARALLEL_THRESHOLD: usize = 4 * (2 * sum_tree::TREE_BASE);
117
118 if new_chunks.len() >= PARALLEL_THRESHOLD {
119 self.chunks.par_extend(new_chunks.into_vec(), &());
120 } else {
121 self.chunks.extend(new_chunks, &());
122 }
123
124 self.check_invariants();
125 }
126
127 /// A copy of `push` specialized for working with large quantities of text.
128 fn push_large(&mut self, mut text: &str) {
129 // To avoid frequent reallocs when loading large swaths of file contents,
130 // we estimate worst-case `new_chunks` capacity;
131 // Chunk is a fixed-capacity buffer. If a character falls on
132 // chunk boundary, we push it off to the following chunk (thus leaving a small bit of capacity unfilled in current chunk).
133 // Worst-case chunk count when loading a file is then a case where every chunk ends up with that unused capacity.
134 // Since we're working with UTF-8, each character is at most 4 bytes wide. It follows then that the worst case is where
135 // a chunk ends with 3 bytes of a 4-byte character. These 3 bytes end up being stored in the following chunk, thus wasting
136 // 3 bytes of storage in current chunk.
137 // For example, a 1024-byte string can occupy between 32 (full ASCII, 1024/32) and 36 (full 4-byte UTF-8, 1024 / 29 rounded up) chunks.
138 const MIN_CHUNK_SIZE: usize = 2 * CHUNK_BASE - 3;
139
140 // We also round up the capacity up by one, for a good measure; we *really* don't want to realloc here, as we assume that the # of characters
141 // we're working with there is large.
142 let capacity = (text.len() + MIN_CHUNK_SIZE - 1) / MIN_CHUNK_SIZE;
143 let mut new_chunks = Vec::with_capacity(capacity);
144
145 while !text.is_empty() {
146 let mut split_ix = cmp::min(2 * CHUNK_BASE, text.len());
147 while !text.is_char_boundary(split_ix) {
148 split_ix -= 1;
149 }
150 let (chunk, remainder) = text.split_at(split_ix);
151 new_chunks.push(Chunk(ArrayString::from(chunk).unwrap()));
152 text = remainder;
153 }
154
155 #[cfg(test)]
156 const PARALLEL_THRESHOLD: usize = 4;
157 #[cfg(not(test))]
158 const PARALLEL_THRESHOLD: usize = 4 * (2 * sum_tree::TREE_BASE);
159
160 if new_chunks.len() >= PARALLEL_THRESHOLD {
161 self.chunks.par_extend(new_chunks, &());
162 } else {
163 self.chunks.extend(new_chunks, &());
164 }
165
166 self.check_invariants();
167 }
168 pub fn push_front(&mut self, text: &str) {
169 let suffix = mem::replace(self, Rope::from(text));
170 self.append(suffix);
171 }
172
173 fn check_invariants(&self) {
174 #[cfg(test)]
175 {
176 // Ensure all chunks except maybe the last one are not underflowing.
177 // Allow some wiggle room for multibyte characters at chunk boundaries.
178 let mut chunks = self.chunks.cursor::<()>().peekable();
179 while let Some(chunk) = chunks.next() {
180 if chunks.peek().is_some() {
181 assert!(chunk.0.len() + 3 >= CHUNK_BASE);
182 }
183 }
184 }
185 }
186
187 pub fn summary(&self) -> TextSummary {
188 self.chunks.summary().text.clone()
189 }
190
191 pub fn len(&self) -> usize {
192 self.chunks.extent(&())
193 }
194
195 pub fn is_empty(&self) -> bool {
196 self.len() == 0
197 }
198
199 pub fn max_point(&self) -> Point {
200 self.chunks.extent(&())
201 }
202
203 pub fn max_point_utf16(&self) -> PointUtf16 {
204 self.chunks.extent(&())
205 }
206
207 pub fn cursor(&self, offset: usize) -> Cursor {
208 Cursor::new(self, offset)
209 }
210
211 pub fn chars(&self) -> impl Iterator<Item = char> + '_ {
212 self.chars_at(0)
213 }
214
215 pub fn chars_at(&self, start: usize) -> impl Iterator<Item = char> + '_ {
216 self.chunks_in_range(start..self.len()).flat_map(str::chars)
217 }
218
219 pub fn reversed_chars_at(&self, start: usize) -> impl Iterator<Item = char> + '_ {
220 self.reversed_chunks_in_range(0..start)
221 .flat_map(|chunk| chunk.chars().rev())
222 }
223
224 pub fn bytes_in_range(&self, range: Range<usize>) -> Bytes {
225 Bytes::new(self, range, false)
226 }
227
228 pub fn reversed_bytes_in_range(&self, range: Range<usize>) -> Bytes {
229 Bytes::new(self, range, true)
230 }
231
232 pub fn chunks(&self) -> Chunks {
233 self.chunks_in_range(0..self.len())
234 }
235
236 pub fn chunks_in_range(&self, range: Range<usize>) -> Chunks {
237 Chunks::new(self, range, false)
238 }
239
240 pub fn reversed_chunks_in_range(&self, range: Range<usize>) -> Chunks {
241 Chunks::new(self, range, true)
242 }
243
244 pub fn offset_to_offset_utf16(&self, offset: usize) -> OffsetUtf16 {
245 if offset >= self.summary().len {
246 return self.summary().len_utf16;
247 }
248 let mut cursor = self.chunks.cursor::<(usize, OffsetUtf16)>();
249 cursor.seek(&offset, Bias::Left, &());
250 let overshoot = offset - cursor.start().0;
251 cursor.start().1
252 + cursor.item().map_or(Default::default(), |chunk| {
253 chunk.offset_to_offset_utf16(overshoot)
254 })
255 }
256
257 pub fn offset_utf16_to_offset(&self, offset: OffsetUtf16) -> usize {
258 if offset >= self.summary().len_utf16 {
259 return self.summary().len;
260 }
261 let mut cursor = self.chunks.cursor::<(OffsetUtf16, usize)>();
262 cursor.seek(&offset, Bias::Left, &());
263 let overshoot = offset - cursor.start().0;
264 cursor.start().1
265 + cursor.item().map_or(Default::default(), |chunk| {
266 chunk.offset_utf16_to_offset(overshoot)
267 })
268 }
269
270 pub fn offset_to_point(&self, offset: usize) -> Point {
271 if offset >= self.summary().len {
272 return self.summary().lines;
273 }
274 let mut cursor = self.chunks.cursor::<(usize, Point)>();
275 cursor.seek(&offset, Bias::Left, &());
276 let overshoot = offset - cursor.start().0;
277 cursor.start().1
278 + cursor
279 .item()
280 .map_or(Point::zero(), |chunk| chunk.offset_to_point(overshoot))
281 }
282
283 pub fn offset_to_point_utf16(&self, offset: usize) -> PointUtf16 {
284 if offset >= self.summary().len {
285 return self.summary().lines_utf16();
286 }
287 let mut cursor = self.chunks.cursor::<(usize, PointUtf16)>();
288 cursor.seek(&offset, Bias::Left, &());
289 let overshoot = offset - cursor.start().0;
290 cursor.start().1
291 + cursor.item().map_or(PointUtf16::zero(), |chunk| {
292 chunk.offset_to_point_utf16(overshoot)
293 })
294 }
295
296 pub fn point_to_point_utf16(&self, point: Point) -> PointUtf16 {
297 if point >= self.summary().lines {
298 return self.summary().lines_utf16();
299 }
300 let mut cursor = self.chunks.cursor::<(Point, PointUtf16)>();
301 cursor.seek(&point, Bias::Left, &());
302 let overshoot = point - cursor.start().0;
303 cursor.start().1
304 + cursor.item().map_or(PointUtf16::zero(), |chunk| {
305 chunk.point_to_point_utf16(overshoot)
306 })
307 }
308
309 pub fn point_to_offset(&self, point: Point) -> usize {
310 if point >= self.summary().lines {
311 return self.summary().len;
312 }
313 let mut cursor = self.chunks.cursor::<(Point, usize)>();
314 cursor.seek(&point, Bias::Left, &());
315 let overshoot = point - cursor.start().0;
316 cursor.start().1
317 + cursor
318 .item()
319 .map_or(0, |chunk| chunk.point_to_offset(overshoot))
320 }
321
322 pub fn point_utf16_to_offset(&self, point: PointUtf16) -> usize {
323 self.point_utf16_to_offset_impl(point, false)
324 }
325
326 pub fn unclipped_point_utf16_to_offset(&self, point: Unclipped<PointUtf16>) -> usize {
327 self.point_utf16_to_offset_impl(point.0, true)
328 }
329
330 fn point_utf16_to_offset_impl(&self, point: PointUtf16, clip: bool) -> usize {
331 if point >= self.summary().lines_utf16() {
332 return self.summary().len;
333 }
334 let mut cursor = self.chunks.cursor::<(PointUtf16, usize)>();
335 cursor.seek(&point, Bias::Left, &());
336 let overshoot = point - cursor.start().0;
337 cursor.start().1
338 + cursor
339 .item()
340 .map_or(0, |chunk| chunk.point_utf16_to_offset(overshoot, clip))
341 }
342
343 pub fn unclipped_point_utf16_to_point(&self, point: Unclipped<PointUtf16>) -> Point {
344 if point.0 >= self.summary().lines_utf16() {
345 return self.summary().lines;
346 }
347 let mut cursor = self.chunks.cursor::<(PointUtf16, Point)>();
348 cursor.seek(&point.0, Bias::Left, &());
349 let overshoot = Unclipped(point.0 - cursor.start().0);
350 cursor.start().1
351 + cursor.item().map_or(Point::zero(), |chunk| {
352 chunk.unclipped_point_utf16_to_point(overshoot)
353 })
354 }
355
356 pub fn clip_offset(&self, mut offset: usize, bias: Bias) -> usize {
357 let mut cursor = self.chunks.cursor::<usize>();
358 cursor.seek(&offset, Bias::Left, &());
359 if let Some(chunk) = cursor.item() {
360 let mut ix = offset - cursor.start();
361 while !chunk.0.is_char_boundary(ix) {
362 match bias {
363 Bias::Left => {
364 ix -= 1;
365 offset -= 1;
366 }
367 Bias::Right => {
368 ix += 1;
369 offset += 1;
370 }
371 }
372 }
373 offset
374 } else {
375 self.summary().len
376 }
377 }
378
379 pub fn clip_offset_utf16(&self, offset: OffsetUtf16, bias: Bias) -> OffsetUtf16 {
380 let mut cursor = self.chunks.cursor::<OffsetUtf16>();
381 cursor.seek(&offset, Bias::Right, &());
382 if let Some(chunk) = cursor.item() {
383 let overshoot = offset - cursor.start();
384 *cursor.start() + chunk.clip_offset_utf16(overshoot, bias)
385 } else {
386 self.summary().len_utf16
387 }
388 }
389
390 pub fn clip_point(&self, point: Point, bias: Bias) -> Point {
391 let mut cursor = self.chunks.cursor::<Point>();
392 cursor.seek(&point, Bias::Right, &());
393 if let Some(chunk) = cursor.item() {
394 let overshoot = point - cursor.start();
395 *cursor.start() + chunk.clip_point(overshoot, bias)
396 } else {
397 self.summary().lines
398 }
399 }
400
401 pub fn clip_point_utf16(&self, point: Unclipped<PointUtf16>, bias: Bias) -> PointUtf16 {
402 let mut cursor = self.chunks.cursor::<PointUtf16>();
403 cursor.seek(&point.0, Bias::Right, &());
404 if let Some(chunk) = cursor.item() {
405 let overshoot = Unclipped(point.0 - cursor.start());
406 *cursor.start() + chunk.clip_point_utf16(overshoot, bias)
407 } else {
408 self.summary().lines_utf16()
409 }
410 }
411
412 pub fn line_len(&self, row: u32) -> u32 {
413 self.clip_point(Point::new(row, u32::MAX), Bias::Left)
414 .column
415 }
416}
417
418impl<'a> From<&'a str> for Rope {
419 fn from(text: &'a str) -> Self {
420 let mut rope = Self::new();
421 rope.push(text);
422 rope
423 }
424}
425
426impl<'a> FromIterator<&'a str> for Rope {
427 fn from_iter<T: IntoIterator<Item = &'a str>>(iter: T) -> Self {
428 let mut rope = Rope::new();
429 for chunk in iter {
430 rope.push(chunk);
431 }
432 rope
433 }
434}
435
436impl From<String> for Rope {
437 fn from(text: String) -> Self {
438 Rope::from(text.as_str())
439 }
440}
441
442impl fmt::Display for Rope {
443 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
444 for chunk in self.chunks() {
445 write!(f, "{}", chunk)?;
446 }
447 Ok(())
448 }
449}
450
451impl fmt::Debug for Rope {
452 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
453 use std::fmt::Write as _;
454
455 write!(f, "\"")?;
456 let mut format_string = String::new();
457 for chunk in self.chunks() {
458 write!(&mut format_string, "{:?}", chunk)?;
459 write!(f, "{}", &format_string[1..format_string.len() - 1])?;
460 format_string.clear();
461 }
462 write!(f, "\"")?;
463 Ok(())
464 }
465}
466
467pub struct Cursor<'a> {
468 rope: &'a Rope,
469 chunks: sum_tree::Cursor<'a, Chunk, usize>,
470 offset: usize,
471}
472
473impl<'a> Cursor<'a> {
474 pub fn new(rope: &'a Rope, offset: usize) -> Self {
475 let mut chunks = rope.chunks.cursor();
476 chunks.seek(&offset, Bias::Right, &());
477 Self {
478 rope,
479 chunks,
480 offset,
481 }
482 }
483
484 pub fn seek_forward(&mut self, end_offset: usize) {
485 debug_assert!(end_offset >= self.offset);
486
487 self.chunks.seek_forward(&end_offset, Bias::Right, &());
488 self.offset = end_offset;
489 }
490
491 pub fn slice(&mut self, end_offset: usize) -> Rope {
492 debug_assert!(
493 end_offset >= self.offset,
494 "cannot slice backwards from {} to {}",
495 self.offset,
496 end_offset
497 );
498
499 let mut slice = Rope::new();
500 if let Some(start_chunk) = self.chunks.item() {
501 let start_ix = self.offset - self.chunks.start();
502 let end_ix = cmp::min(end_offset, self.chunks.end(&())) - self.chunks.start();
503 slice.push(&start_chunk.0[start_ix..end_ix]);
504 }
505
506 if end_offset > self.chunks.end(&()) {
507 self.chunks.next(&());
508 slice.append(Rope {
509 chunks: self.chunks.slice(&end_offset, Bias::Right, &()),
510 });
511 if let Some(end_chunk) = self.chunks.item() {
512 let end_ix = end_offset - self.chunks.start();
513 slice.push(&end_chunk.0[..end_ix]);
514 }
515 }
516
517 self.offset = end_offset;
518 slice
519 }
520
521 pub fn summary<D: TextDimension>(&mut self, end_offset: usize) -> D {
522 debug_assert!(end_offset >= self.offset);
523
524 let mut summary = D::default();
525 if let Some(start_chunk) = self.chunks.item() {
526 let start_ix = self.offset - self.chunks.start();
527 let end_ix = cmp::min(end_offset, self.chunks.end(&())) - self.chunks.start();
528 summary.add_assign(&D::from_text_summary(&TextSummary::from(
529 &start_chunk.0[start_ix..end_ix],
530 )));
531 }
532
533 if end_offset > self.chunks.end(&()) {
534 self.chunks.next(&());
535 summary.add_assign(&self.chunks.summary(&end_offset, Bias::Right, &()));
536 if let Some(end_chunk) = self.chunks.item() {
537 let end_ix = end_offset - self.chunks.start();
538 summary.add_assign(&D::from_text_summary(&TextSummary::from(
539 &end_chunk.0[..end_ix],
540 )));
541 }
542 }
543
544 self.offset = end_offset;
545 summary
546 }
547
548 pub fn suffix(mut self) -> Rope {
549 self.slice(self.rope.chunks.extent(&()))
550 }
551
552 pub fn offset(&self) -> usize {
553 self.offset
554 }
555}
556
557pub struct Chunks<'a> {
558 chunks: sum_tree::Cursor<'a, Chunk, usize>,
559 range: Range<usize>,
560 reversed: bool,
561}
562
563impl<'a> Chunks<'a> {
564 pub fn new(rope: &'a Rope, range: Range<usize>, reversed: bool) -> Self {
565 let mut chunks = rope.chunks.cursor();
566 if reversed {
567 chunks.seek(&range.end, Bias::Left, &());
568 } else {
569 chunks.seek(&range.start, Bias::Right, &());
570 }
571 Self {
572 chunks,
573 range,
574 reversed,
575 }
576 }
577
578 pub fn offset(&self) -> usize {
579 if self.reversed {
580 self.range.end.min(self.chunks.end(&()))
581 } else {
582 self.range.start.max(*self.chunks.start())
583 }
584 }
585
586 pub fn seek(&mut self, offset: usize) {
587 let bias = if self.reversed {
588 Bias::Left
589 } else {
590 Bias::Right
591 };
592
593 if offset >= self.chunks.end(&()) {
594 self.chunks.seek_forward(&offset, bias, &());
595 } else {
596 self.chunks.seek(&offset, bias, &());
597 }
598
599 if self.reversed {
600 self.range.end = offset;
601 } else {
602 self.range.start = offset;
603 }
604 }
605
606 pub fn peek(&self) -> Option<&'a str> {
607 let chunk = self.chunks.item()?;
608 if self.reversed && self.range.start >= self.chunks.end(&()) {
609 return None;
610 }
611 let chunk_start = *self.chunks.start();
612 if self.range.end <= chunk_start {
613 return None;
614 }
615
616 let start = self.range.start.saturating_sub(chunk_start);
617 let end = self.range.end - chunk_start;
618 Some(&chunk.0[start..chunk.0.len().min(end)])
619 }
620
621 pub fn lines(self) -> Lines<'a> {
622 Lines {
623 chunks: self,
624 current_line: String::new(),
625 done: false,
626 }
627 }
628}
629
630impl<'a> Iterator for Chunks<'a> {
631 type Item = &'a str;
632
633 fn next(&mut self) -> Option<Self::Item> {
634 let result = self.peek();
635 if result.is_some() {
636 if self.reversed {
637 self.chunks.prev(&());
638 } else {
639 self.chunks.next(&());
640 }
641 }
642 result
643 }
644}
645
646pub struct Bytes<'a> {
647 chunks: sum_tree::Cursor<'a, Chunk, usize>,
648 range: Range<usize>,
649 reversed: bool,
650}
651
652impl<'a> Bytes<'a> {
653 pub fn new(rope: &'a Rope, range: Range<usize>, reversed: bool) -> Self {
654 let mut chunks = rope.chunks.cursor();
655 if reversed {
656 chunks.seek(&range.end, Bias::Left, &());
657 } else {
658 chunks.seek(&range.start, Bias::Right, &());
659 }
660 Self {
661 chunks,
662 range,
663 reversed,
664 }
665 }
666
667 pub fn peek(&self) -> Option<&'a [u8]> {
668 let chunk = self.chunks.item()?;
669 if self.reversed && self.range.start >= self.chunks.end(&()) {
670 return None;
671 }
672 let chunk_start = *self.chunks.start();
673 if self.range.end <= chunk_start {
674 return None;
675 }
676 let start = self.range.start.saturating_sub(chunk_start);
677 let end = self.range.end - chunk_start;
678 Some(&chunk.0.as_bytes()[start..chunk.0.len().min(end)])
679 }
680}
681
682impl<'a> Iterator for Bytes<'a> {
683 type Item = &'a [u8];
684
685 fn next(&mut self) -> Option<Self::Item> {
686 let result = self.peek();
687 if result.is_some() {
688 if self.reversed {
689 self.chunks.prev(&());
690 } else {
691 self.chunks.next(&());
692 }
693 }
694 result
695 }
696}
697
698impl<'a> io::Read for Bytes<'a> {
699 fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
700 if let Some(chunk) = self.peek() {
701 let len = cmp::min(buf.len(), chunk.len());
702 if self.reversed {
703 buf[..len].copy_from_slice(&chunk[chunk.len() - len..]);
704 buf[..len].reverse();
705 self.range.end -= len;
706 } else {
707 buf[..len].copy_from_slice(&chunk[..len]);
708 self.range.start += len;
709 }
710
711 if len == chunk.len() {
712 if self.reversed {
713 self.chunks.prev(&());
714 } else {
715 self.chunks.next(&());
716 }
717 }
718 Ok(len)
719 } else {
720 Ok(0)
721 }
722 }
723}
724
725pub struct Lines<'a> {
726 chunks: Chunks<'a>,
727 current_line: String,
728 done: bool,
729}
730
731impl<'a> Lines<'a> {
732 pub fn next(&mut self) -> Option<&str> {
733 if self.done {
734 return None;
735 }
736
737 self.current_line.clear();
738
739 while let Some(chunk) = self.chunks.peek() {
740 let mut lines = chunk.split('\n').peekable();
741 while let Some(line) = lines.next() {
742 self.current_line.push_str(line);
743 if lines.peek().is_some() {
744 self.chunks
745 .seek(self.chunks.offset() + line.len() + "\n".len());
746 return Some(&self.current_line);
747 }
748 }
749
750 self.chunks.next();
751 }
752
753 self.done = true;
754 Some(&self.current_line)
755 }
756
757 pub fn seek(&mut self, offset: usize) {
758 self.chunks.seek(offset);
759 self.current_line.clear();
760 self.done = false;
761 }
762
763 pub fn offset(&self) -> usize {
764 self.chunks.offset()
765 }
766}
767
768#[derive(Clone, Debug, Default)]
769struct Chunk(ArrayString<{ 2 * CHUNK_BASE }>);
770
771impl Chunk {
772 fn offset_to_offset_utf16(&self, target: usize) -> OffsetUtf16 {
773 let mut offset = 0;
774 let mut offset_utf16 = OffsetUtf16(0);
775 for ch in self.0.chars() {
776 if offset >= target {
777 break;
778 }
779
780 offset += ch.len_utf8();
781 offset_utf16.0 += ch.len_utf16();
782 }
783 offset_utf16
784 }
785
786 fn offset_utf16_to_offset(&self, target: OffsetUtf16) -> usize {
787 let mut offset_utf16 = OffsetUtf16(0);
788 let mut offset = 0;
789 for ch in self.0.chars() {
790 if offset_utf16 >= target {
791 break;
792 }
793
794 offset += ch.len_utf8();
795 offset_utf16.0 += ch.len_utf16();
796 }
797 offset
798 }
799
800 fn offset_to_point(&self, target: usize) -> Point {
801 let mut offset = 0;
802 let mut point = Point::new(0, 0);
803 for ch in self.0.chars() {
804 if offset >= target {
805 break;
806 }
807
808 if ch == '\n' {
809 point.row += 1;
810 point.column = 0;
811 } else {
812 point.column += ch.len_utf8() as u32;
813 }
814 offset += ch.len_utf8();
815 }
816 point
817 }
818
819 fn offset_to_point_utf16(&self, target: usize) -> PointUtf16 {
820 let mut offset = 0;
821 let mut point = PointUtf16::new(0, 0);
822 for ch in self.0.chars() {
823 if offset >= target {
824 break;
825 }
826
827 if ch == '\n' {
828 point.row += 1;
829 point.column = 0;
830 } else {
831 point.column += ch.len_utf16() as u32;
832 }
833 offset += ch.len_utf8();
834 }
835 point
836 }
837
838 fn point_to_offset(&self, target: Point) -> usize {
839 let mut offset = 0;
840 let mut point = Point::new(0, 0);
841
842 for ch in self.0.chars() {
843 if point >= target {
844 if point > target {
845 debug_panic!("point {target:?} is inside of character {ch:?}");
846 }
847 break;
848 }
849
850 if ch == '\n' {
851 point.row += 1;
852 point.column = 0;
853
854 if point.row > target.row {
855 debug_panic!(
856 "point {target:?} is beyond the end of a line with length {}",
857 point.column
858 );
859 break;
860 }
861 } else {
862 point.column += ch.len_utf8() as u32;
863 }
864
865 offset += ch.len_utf8();
866 }
867
868 offset
869 }
870
871 fn point_to_point_utf16(&self, target: Point) -> PointUtf16 {
872 let mut point = Point::zero();
873 let mut point_utf16 = PointUtf16::new(0, 0);
874 for ch in self.0.chars() {
875 if point >= target {
876 break;
877 }
878
879 if ch == '\n' {
880 point_utf16.row += 1;
881 point_utf16.column = 0;
882 point.row += 1;
883 point.column = 0;
884 } else {
885 point_utf16.column += ch.len_utf16() as u32;
886 point.column += ch.len_utf8() as u32;
887 }
888 }
889 point_utf16
890 }
891
892 fn point_utf16_to_offset(&self, target: PointUtf16, clip: bool) -> usize {
893 let mut offset = 0;
894 let mut point = PointUtf16::new(0, 0);
895
896 for ch in self.0.chars() {
897 if point == target {
898 break;
899 }
900
901 if ch == '\n' {
902 point.row += 1;
903 point.column = 0;
904
905 if point.row > target.row {
906 if !clip {
907 debug_panic!(
908 "point {target:?} is beyond the end of a line with length {}",
909 point.column
910 );
911 }
912 // Return the offset of the newline
913 return offset;
914 }
915 } else {
916 point.column += ch.len_utf16() as u32;
917 }
918
919 if point > target {
920 if !clip {
921 debug_panic!("point {target:?} is inside of codepoint {ch:?}");
922 }
923 // Return the offset of the codepoint which we have landed within, bias left
924 return offset;
925 }
926
927 offset += ch.len_utf8();
928 }
929
930 offset
931 }
932
933 fn unclipped_point_utf16_to_point(&self, target: Unclipped<PointUtf16>) -> Point {
934 let mut point = Point::zero();
935 let mut point_utf16 = PointUtf16::zero();
936
937 for ch in self.0.chars() {
938 if point_utf16 == target.0 {
939 break;
940 }
941
942 if point_utf16 > target.0 {
943 // If the point is past the end of a line or inside of a code point,
944 // return the last valid point before the target.
945 return point;
946 }
947
948 if ch == '\n' {
949 point_utf16 += PointUtf16::new(1, 0);
950 point += Point::new(1, 0);
951 } else {
952 point_utf16 += PointUtf16::new(0, ch.len_utf16() as u32);
953 point += Point::new(0, ch.len_utf8() as u32);
954 }
955 }
956
957 point
958 }
959
960 fn clip_point(&self, target: Point, bias: Bias) -> Point {
961 for (row, line) in self.0.split('\n').enumerate() {
962 if row == target.row as usize {
963 let bytes = line.as_bytes();
964 let mut column = target.column.min(bytes.len() as u32) as usize;
965 if column == 0
966 || column == bytes.len()
967 || (bytes[column - 1] < 128 && bytes[column] < 128)
968 {
969 return Point::new(row as u32, column as u32);
970 }
971
972 let mut grapheme_cursor = GraphemeCursor::new(column, bytes.len(), true);
973 loop {
974 if line.is_char_boundary(column) {
975 if grapheme_cursor.is_boundary(line, 0).unwrap_or(false) {
976 break;
977 }
978 }
979
980 match bias {
981 Bias::Left => column -= 1,
982 Bias::Right => column += 1,
983 }
984 grapheme_cursor.set_cursor(column);
985 }
986 return Point::new(row as u32, column as u32);
987 }
988 }
989 unreachable!()
990 }
991
992 fn clip_point_utf16(&self, target: Unclipped<PointUtf16>, bias: Bias) -> PointUtf16 {
993 for (row, line) in self.0.split('\n').enumerate() {
994 if row == target.0.row as usize {
995 let mut code_units = line.encode_utf16();
996 let mut column = code_units.by_ref().take(target.0.column as usize).count();
997 if char::decode_utf16(code_units).next().transpose().is_err() {
998 match bias {
999 Bias::Left => column -= 1,
1000 Bias::Right => column += 1,
1001 }
1002 }
1003 return PointUtf16::new(row as u32, column as u32);
1004 }
1005 }
1006 unreachable!()
1007 }
1008
1009 fn clip_offset_utf16(&self, target: OffsetUtf16, bias: Bias) -> OffsetUtf16 {
1010 let mut code_units = self.0.encode_utf16();
1011 let mut offset = code_units.by_ref().take(target.0).count();
1012 if char::decode_utf16(code_units).next().transpose().is_err() {
1013 match bias {
1014 Bias::Left => offset -= 1,
1015 Bias::Right => offset += 1,
1016 }
1017 }
1018 OffsetUtf16(offset)
1019 }
1020}
1021
1022impl sum_tree::Item for Chunk {
1023 type Summary = ChunkSummary;
1024
1025 fn summary(&self) -> Self::Summary {
1026 ChunkSummary::from(self.0.as_str())
1027 }
1028}
1029
1030#[derive(Clone, Debug, Default, Eq, PartialEq)]
1031pub struct ChunkSummary {
1032 text: TextSummary,
1033}
1034
1035impl<'a> From<&'a str> for ChunkSummary {
1036 fn from(text: &'a str) -> Self {
1037 Self {
1038 text: TextSummary::from(text),
1039 }
1040 }
1041}
1042
1043impl sum_tree::Summary for ChunkSummary {
1044 type Context = ();
1045
1046 fn add_summary(&mut self, summary: &Self, _: &()) {
1047 self.text += &summary.text;
1048 }
1049}
1050
1051/// Summary of a string of text.
1052#[derive(Clone, Debug, Default, Eq, PartialEq)]
1053pub struct TextSummary {
1054 /// Length in UTF-8
1055 pub len: usize,
1056 /// Length in UTF-16 code units
1057 pub len_utf16: OffsetUtf16,
1058 /// A point representing the number of lines and the length of the last line
1059 pub lines: Point,
1060 /// How many `char`s are in the first line
1061 pub first_line_chars: u32,
1062 /// How many `char`s are in the last line
1063 pub last_line_chars: u32,
1064 /// How many UTF-16 code units are in the last line
1065 pub last_line_len_utf16: u32,
1066 /// The row idx of the longest row
1067 pub longest_row: u32,
1068 /// How many `char`s are in the longest row
1069 pub longest_row_chars: u32,
1070}
1071
1072impl TextSummary {
1073 pub fn lines_utf16(&self) -> PointUtf16 {
1074 PointUtf16 {
1075 row: self.lines.row,
1076 column: self.last_line_len_utf16,
1077 }
1078 }
1079}
1080
1081impl<'a> From<&'a str> for TextSummary {
1082 fn from(text: &'a str) -> Self {
1083 let mut len_utf16 = OffsetUtf16(0);
1084 let mut lines = Point::new(0, 0);
1085 let mut first_line_chars = 0;
1086 let mut last_line_chars = 0;
1087 let mut last_line_len_utf16 = 0;
1088 let mut longest_row = 0;
1089 let mut longest_row_chars = 0;
1090 for c in text.chars() {
1091 len_utf16.0 += c.len_utf16();
1092
1093 if c == '\n' {
1094 lines += Point::new(1, 0);
1095 last_line_len_utf16 = 0;
1096 last_line_chars = 0;
1097 } else {
1098 lines.column += c.len_utf8() as u32;
1099 last_line_len_utf16 += c.len_utf16() as u32;
1100 last_line_chars += 1;
1101 }
1102
1103 if lines.row == 0 {
1104 first_line_chars = last_line_chars;
1105 }
1106
1107 if last_line_chars > longest_row_chars {
1108 longest_row = lines.row;
1109 longest_row_chars = last_line_chars;
1110 }
1111 }
1112
1113 TextSummary {
1114 len: text.len(),
1115 len_utf16,
1116 lines,
1117 first_line_chars,
1118 last_line_chars,
1119 last_line_len_utf16,
1120 longest_row,
1121 longest_row_chars,
1122 }
1123 }
1124}
1125
1126impl sum_tree::Summary for TextSummary {
1127 type Context = ();
1128
1129 fn add_summary(&mut self, summary: &Self, _: &Self::Context) {
1130 *self += summary;
1131 }
1132}
1133
1134impl std::ops::Add<Self> for TextSummary {
1135 type Output = Self;
1136
1137 fn add(mut self, rhs: Self) -> Self::Output {
1138 AddAssign::add_assign(&mut self, &rhs);
1139 self
1140 }
1141}
1142
1143impl<'a> std::ops::AddAssign<&'a Self> for TextSummary {
1144 fn add_assign(&mut self, other: &'a Self) {
1145 let joined_chars = self.last_line_chars + other.first_line_chars;
1146 if joined_chars > self.longest_row_chars {
1147 self.longest_row = self.lines.row;
1148 self.longest_row_chars = joined_chars;
1149 }
1150 if other.longest_row_chars > self.longest_row_chars {
1151 self.longest_row = self.lines.row + other.longest_row;
1152 self.longest_row_chars = other.longest_row_chars;
1153 }
1154
1155 if self.lines.row == 0 {
1156 self.first_line_chars += other.first_line_chars;
1157 }
1158
1159 if other.lines.row == 0 {
1160 self.last_line_chars += other.first_line_chars;
1161 self.last_line_len_utf16 += other.last_line_len_utf16;
1162 } else {
1163 self.last_line_chars = other.last_line_chars;
1164 self.last_line_len_utf16 = other.last_line_len_utf16;
1165 }
1166
1167 self.len += other.len;
1168 self.len_utf16 += other.len_utf16;
1169 self.lines += other.lines;
1170 }
1171}
1172
1173impl std::ops::AddAssign<Self> for TextSummary {
1174 fn add_assign(&mut self, other: Self) {
1175 *self += &other;
1176 }
1177}
1178
1179pub trait TextDimension: 'static + for<'a> Dimension<'a, ChunkSummary> {
1180 fn from_text_summary(summary: &TextSummary) -> Self;
1181 fn add_assign(&mut self, other: &Self);
1182}
1183
1184impl<D1: TextDimension, D2: TextDimension> TextDimension for (D1, D2) {
1185 fn from_text_summary(summary: &TextSummary) -> Self {
1186 (
1187 D1::from_text_summary(summary),
1188 D2::from_text_summary(summary),
1189 )
1190 }
1191
1192 fn add_assign(&mut self, other: &Self) {
1193 self.0.add_assign(&other.0);
1194 self.1.add_assign(&other.1);
1195 }
1196}
1197
1198impl<'a> sum_tree::Dimension<'a, ChunkSummary> for TextSummary {
1199 fn add_summary(&mut self, summary: &'a ChunkSummary, _: &()) {
1200 *self += &summary.text;
1201 }
1202}
1203
1204impl TextDimension for TextSummary {
1205 fn from_text_summary(summary: &TextSummary) -> Self {
1206 summary.clone()
1207 }
1208
1209 fn add_assign(&mut self, other: &Self) {
1210 *self += other;
1211 }
1212}
1213
1214impl<'a> sum_tree::Dimension<'a, ChunkSummary> for usize {
1215 fn add_summary(&mut self, summary: &'a ChunkSummary, _: &()) {
1216 *self += summary.text.len;
1217 }
1218}
1219
1220impl TextDimension for usize {
1221 fn from_text_summary(summary: &TextSummary) -> Self {
1222 summary.len
1223 }
1224
1225 fn add_assign(&mut self, other: &Self) {
1226 *self += other;
1227 }
1228}
1229
1230impl<'a> sum_tree::Dimension<'a, ChunkSummary> for OffsetUtf16 {
1231 fn add_summary(&mut self, summary: &'a ChunkSummary, _: &()) {
1232 *self += summary.text.len_utf16;
1233 }
1234}
1235
1236impl TextDimension for OffsetUtf16 {
1237 fn from_text_summary(summary: &TextSummary) -> Self {
1238 summary.len_utf16
1239 }
1240
1241 fn add_assign(&mut self, other: &Self) {
1242 *self += other;
1243 }
1244}
1245
1246impl<'a> sum_tree::Dimension<'a, ChunkSummary> for Point {
1247 fn add_summary(&mut self, summary: &'a ChunkSummary, _: &()) {
1248 *self += summary.text.lines;
1249 }
1250}
1251
1252impl TextDimension for Point {
1253 fn from_text_summary(summary: &TextSummary) -> Self {
1254 summary.lines
1255 }
1256
1257 fn add_assign(&mut self, other: &Self) {
1258 *self += other;
1259 }
1260}
1261
1262impl<'a> sum_tree::Dimension<'a, ChunkSummary> for PointUtf16 {
1263 fn add_summary(&mut self, summary: &'a ChunkSummary, _: &()) {
1264 *self += summary.text.lines_utf16();
1265 }
1266}
1267
1268impl TextDimension for PointUtf16 {
1269 fn from_text_summary(summary: &TextSummary) -> Self {
1270 summary.lines_utf16()
1271 }
1272
1273 fn add_assign(&mut self, other: &Self) {
1274 *self += other;
1275 }
1276}
1277
1278#[cfg(test)]
1279mod tests {
1280 use super::*;
1281 use rand::prelude::*;
1282 use std::{cmp::Ordering, env, io::Read};
1283 use util::RandomCharIter;
1284 use Bias::{Left, Right};
1285
1286 #[test]
1287 fn test_all_4_byte_chars() {
1288 let mut rope = Rope::new();
1289 let text = "🏀".repeat(256);
1290 rope.push(&text);
1291 assert_eq!(rope.text(), text);
1292 }
1293
1294 #[test]
1295 fn test_clip() {
1296 let rope = Rope::from("🧘");
1297
1298 assert_eq!(rope.clip_offset(1, Bias::Left), 0);
1299 assert_eq!(rope.clip_offset(1, Bias::Right), 4);
1300 assert_eq!(rope.clip_offset(5, Bias::Right), 4);
1301
1302 assert_eq!(
1303 rope.clip_point(Point::new(0, 1), Bias::Left),
1304 Point::new(0, 0)
1305 );
1306 assert_eq!(
1307 rope.clip_point(Point::new(0, 1), Bias::Right),
1308 Point::new(0, 4)
1309 );
1310 assert_eq!(
1311 rope.clip_point(Point::new(0, 5), Bias::Right),
1312 Point::new(0, 4)
1313 );
1314
1315 assert_eq!(
1316 rope.clip_point_utf16(Unclipped(PointUtf16::new(0, 1)), Bias::Left),
1317 PointUtf16::new(0, 0)
1318 );
1319 assert_eq!(
1320 rope.clip_point_utf16(Unclipped(PointUtf16::new(0, 1)), Bias::Right),
1321 PointUtf16::new(0, 2)
1322 );
1323 assert_eq!(
1324 rope.clip_point_utf16(Unclipped(PointUtf16::new(0, 3)), Bias::Right),
1325 PointUtf16::new(0, 2)
1326 );
1327
1328 assert_eq!(
1329 rope.clip_offset_utf16(OffsetUtf16(1), Bias::Left),
1330 OffsetUtf16(0)
1331 );
1332 assert_eq!(
1333 rope.clip_offset_utf16(OffsetUtf16(1), Bias::Right),
1334 OffsetUtf16(2)
1335 );
1336 assert_eq!(
1337 rope.clip_offset_utf16(OffsetUtf16(3), Bias::Right),
1338 OffsetUtf16(2)
1339 );
1340 }
1341
1342 #[test]
1343 fn test_lines() {
1344 let rope = Rope::from("abc\ndefg\nhi");
1345 let mut lines = rope.chunks().lines();
1346 assert_eq!(lines.next(), Some("abc"));
1347 assert_eq!(lines.next(), Some("defg"));
1348 assert_eq!(lines.next(), Some("hi"));
1349 assert_eq!(lines.next(), None);
1350
1351 let rope = Rope::from("abc\ndefg\nhi\n");
1352 let mut lines = rope.chunks().lines();
1353 assert_eq!(lines.next(), Some("abc"));
1354 assert_eq!(lines.next(), Some("defg"));
1355 assert_eq!(lines.next(), Some("hi"));
1356 assert_eq!(lines.next(), Some(""));
1357 assert_eq!(lines.next(), None);
1358 }
1359
1360 #[gpui::test(iterations = 100)]
1361 fn test_random_rope(mut rng: StdRng) {
1362 let operations = env::var("OPERATIONS")
1363 .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1364 .unwrap_or(10);
1365
1366 let mut expected = String::new();
1367 let mut actual = Rope::new();
1368 for _ in 0..operations {
1369 let end_ix = clip_offset(&expected, rng.gen_range(0..=expected.len()), Right);
1370 let start_ix = clip_offset(&expected, rng.gen_range(0..=end_ix), Left);
1371 let len = rng.gen_range(0..=64);
1372 let new_text: String = RandomCharIter::new(&mut rng).take(len).collect();
1373
1374 let mut new_actual = Rope::new();
1375 let mut cursor = actual.cursor(0);
1376 new_actual.append(cursor.slice(start_ix));
1377 new_actual.push(&new_text);
1378 cursor.seek_forward(end_ix);
1379 new_actual.append(cursor.suffix());
1380 actual = new_actual;
1381
1382 expected.replace_range(start_ix..end_ix, &new_text);
1383
1384 assert_eq!(actual.text(), expected);
1385 log::info!("text: {:?}", expected);
1386
1387 for _ in 0..5 {
1388 let end_ix = clip_offset(&expected, rng.gen_range(0..=expected.len()), Right);
1389 let start_ix = clip_offset(&expected, rng.gen_range(0..=end_ix), Left);
1390
1391 let actual_text = actual.chunks_in_range(start_ix..end_ix).collect::<String>();
1392 assert_eq!(actual_text, &expected[start_ix..end_ix]);
1393
1394 let mut actual_text = String::new();
1395 actual
1396 .bytes_in_range(start_ix..end_ix)
1397 .read_to_string(&mut actual_text)
1398 .unwrap();
1399 assert_eq!(actual_text, &expected[start_ix..end_ix]);
1400
1401 assert_eq!(
1402 actual
1403 .reversed_chunks_in_range(start_ix..end_ix)
1404 .collect::<Vec<&str>>()
1405 .into_iter()
1406 .rev()
1407 .collect::<String>(),
1408 &expected[start_ix..end_ix]
1409 );
1410 }
1411
1412 let mut offset_utf16 = OffsetUtf16(0);
1413 let mut point = Point::new(0, 0);
1414 let mut point_utf16 = PointUtf16::new(0, 0);
1415 for (ix, ch) in expected.char_indices().chain(Some((expected.len(), '\0'))) {
1416 assert_eq!(actual.offset_to_point(ix), point, "offset_to_point({})", ix);
1417 assert_eq!(
1418 actual.offset_to_point_utf16(ix),
1419 point_utf16,
1420 "offset_to_point_utf16({})",
1421 ix
1422 );
1423 assert_eq!(
1424 actual.point_to_offset(point),
1425 ix,
1426 "point_to_offset({:?})",
1427 point
1428 );
1429 assert_eq!(
1430 actual.point_utf16_to_offset(point_utf16),
1431 ix,
1432 "point_utf16_to_offset({:?})",
1433 point_utf16
1434 );
1435 assert_eq!(
1436 actual.offset_to_offset_utf16(ix),
1437 offset_utf16,
1438 "offset_to_offset_utf16({:?})",
1439 ix
1440 );
1441 assert_eq!(
1442 actual.offset_utf16_to_offset(offset_utf16),
1443 ix,
1444 "offset_utf16_to_offset({:?})",
1445 offset_utf16
1446 );
1447 if ch == '\n' {
1448 point += Point::new(1, 0);
1449 point_utf16 += PointUtf16::new(1, 0);
1450 } else {
1451 point.column += ch.len_utf8() as u32;
1452 point_utf16.column += ch.len_utf16() as u32;
1453 }
1454 offset_utf16.0 += ch.len_utf16();
1455 }
1456
1457 let mut offset_utf16 = OffsetUtf16(0);
1458 let mut point_utf16 = Unclipped(PointUtf16::zero());
1459 for unit in expected.encode_utf16() {
1460 let left_offset = actual.clip_offset_utf16(offset_utf16, Bias::Left);
1461 let right_offset = actual.clip_offset_utf16(offset_utf16, Bias::Right);
1462 assert!(right_offset >= left_offset);
1463 // Ensure translating UTF-16 offsets to UTF-8 offsets doesn't panic.
1464 actual.offset_utf16_to_offset(left_offset);
1465 actual.offset_utf16_to_offset(right_offset);
1466
1467 let left_point = actual.clip_point_utf16(point_utf16, Bias::Left);
1468 let right_point = actual.clip_point_utf16(point_utf16, Bias::Right);
1469 assert!(right_point >= left_point);
1470 // Ensure translating valid UTF-16 points to offsets doesn't panic.
1471 actual.point_utf16_to_offset(left_point);
1472 actual.point_utf16_to_offset(right_point);
1473
1474 offset_utf16.0 += 1;
1475 if unit == b'\n' as u16 {
1476 point_utf16.0 += PointUtf16::new(1, 0);
1477 } else {
1478 point_utf16.0 += PointUtf16::new(0, 1);
1479 }
1480 }
1481
1482 for _ in 0..5 {
1483 let end_ix = clip_offset(&expected, rng.gen_range(0..=expected.len()), Right);
1484 let start_ix = clip_offset(&expected, rng.gen_range(0..=end_ix), Left);
1485 assert_eq!(
1486 actual.cursor(start_ix).summary::<TextSummary>(end_ix),
1487 TextSummary::from(&expected[start_ix..end_ix])
1488 );
1489 }
1490
1491 let mut expected_longest_rows = Vec::new();
1492 let mut longest_line_len = -1_isize;
1493 for (row, line) in expected.split('\n').enumerate() {
1494 let row = row as u32;
1495 assert_eq!(
1496 actual.line_len(row),
1497 line.len() as u32,
1498 "invalid line len for row {}",
1499 row
1500 );
1501
1502 let line_char_count = line.chars().count() as isize;
1503 match line_char_count.cmp(&longest_line_len) {
1504 Ordering::Less => {}
1505 Ordering::Equal => expected_longest_rows.push(row),
1506 Ordering::Greater => {
1507 longest_line_len = line_char_count;
1508 expected_longest_rows.clear();
1509 expected_longest_rows.push(row);
1510 }
1511 }
1512 }
1513
1514 let longest_row = actual.summary().longest_row;
1515 assert!(
1516 expected_longest_rows.contains(&longest_row),
1517 "incorrect longest row {}. expected {:?} with length {}",
1518 longest_row,
1519 expected_longest_rows,
1520 longest_line_len,
1521 );
1522 }
1523 }
1524
1525 fn clip_offset(text: &str, mut offset: usize, bias: Bias) -> usize {
1526 while !text.is_char_boundary(offset) {
1527 match bias {
1528 Bias::Left => offset -= 1,
1529 Bias::Right => offset += 1,
1530 }
1531 }
1532 offset
1533 }
1534
1535 impl Rope {
1536 fn text(&self) -> String {
1537 let mut text = String::new();
1538 for chunk in self.chunks.cursor::<()>() {
1539 text.push_str(&chunk.0);
1540 }
1541 text
1542 }
1543 }
1544}