fold_map.rs

   1use super::{
   2    inlay_map::{InlayBufferRows, InlayChunks, InlayEdit, InlayOffset, InlayPoint, InlaySnapshot},
   3    TextHighlights,
   4};
   5use crate::{Anchor, AnchorRangeExt, MultiBufferSnapshot, ToOffset};
   6use gpui::{color::Color, fonts::HighlightStyle};
   7use language::{Chunk, Edit, Point, TextSummary};
   8use std::{
   9    any::TypeId,
  10    cmp::{self, Ordering},
  11    iter,
  12    ops::{Add, AddAssign, Range, Sub},
  13};
  14use sum_tree::{Bias, Cursor, FilterCursor, SumTree};
  15
  16#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  17pub struct FoldPoint(pub Point);
  18
  19impl FoldPoint {
  20    pub fn new(row: u32, column: u32) -> Self {
  21        Self(Point::new(row, column))
  22    }
  23
  24    pub fn row(self) -> u32 {
  25        self.0.row
  26    }
  27
  28    pub fn column(self) -> u32 {
  29        self.0.column
  30    }
  31
  32    pub fn row_mut(&mut self) -> &mut u32 {
  33        &mut self.0.row
  34    }
  35
  36    #[cfg(test)]
  37    pub fn column_mut(&mut self) -> &mut u32 {
  38        &mut self.0.column
  39    }
  40
  41    pub fn to_inlay_point(self, snapshot: &FoldSnapshot) -> InlayPoint {
  42        let mut cursor = snapshot.transforms.cursor::<(FoldPoint, InlayPoint)>();
  43        cursor.seek(&self, Bias::Right, &());
  44        let overshoot = self.0 - cursor.start().0 .0;
  45        InlayPoint(cursor.start().1 .0 + overshoot)
  46    }
  47
  48    pub fn to_offset(self, snapshot: &FoldSnapshot) -> FoldOffset {
  49        let mut cursor = snapshot
  50            .transforms
  51            .cursor::<(FoldPoint, TransformSummary)>();
  52        cursor.seek(&self, Bias::Right, &());
  53        let overshoot = self.0 - cursor.start().1.output.lines;
  54        let mut offset = cursor.start().1.output.len;
  55        if !overshoot.is_zero() {
  56            let transform = cursor.item().expect("display point out of range");
  57            assert!(transform.output_text.is_none());
  58            let end_inlay_offset = snapshot
  59                .inlay_snapshot
  60                .to_offset(InlayPoint(cursor.start().1.input.lines + overshoot));
  61            offset += end_inlay_offset.0 - cursor.start().1.input.len;
  62        }
  63        FoldOffset(offset)
  64    }
  65}
  66
  67impl<'a> sum_tree::Dimension<'a, TransformSummary> for FoldPoint {
  68    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
  69        self.0 += &summary.output.lines;
  70    }
  71}
  72
  73pub struct FoldMapWriter<'a>(&'a mut FoldMap);
  74
  75impl<'a> FoldMapWriter<'a> {
  76    pub fn fold<T: ToOffset>(
  77        &mut self,
  78        ranges: impl IntoIterator<Item = Range<T>>,
  79    ) -> (FoldSnapshot, Vec<FoldEdit>) {
  80        let mut edits = Vec::new();
  81        let mut folds = Vec::new();
  82        let snapshot = self.0.snapshot.inlay_snapshot.clone();
  83        for range in ranges.into_iter() {
  84            let buffer = &snapshot.buffer;
  85            let range = range.start.to_offset(&buffer)..range.end.to_offset(&buffer);
  86
  87            // Ignore any empty ranges.
  88            if range.start == range.end {
  89                continue;
  90            }
  91
  92            // For now, ignore any ranges that span an excerpt boundary.
  93            let fold = Fold(buffer.anchor_after(range.start)..buffer.anchor_before(range.end));
  94            if fold.0.start.excerpt_id() != fold.0.end.excerpt_id() {
  95                continue;
  96            }
  97
  98            folds.push(fold);
  99
 100            let inlay_range =
 101                snapshot.to_inlay_offset(range.start)..snapshot.to_inlay_offset(range.end);
 102            edits.push(InlayEdit {
 103                old: inlay_range.clone(),
 104                new: inlay_range,
 105            });
 106        }
 107
 108        let buffer = &snapshot.buffer;
 109        folds.sort_unstable_by(|a, b| sum_tree::SeekTarget::cmp(a, b, buffer));
 110
 111        self.0.snapshot.folds = {
 112            let mut new_tree = SumTree::new();
 113            let mut cursor = self.0.snapshot.folds.cursor::<Fold>();
 114            for fold in folds {
 115                new_tree.append(cursor.slice(&fold, Bias::Right, buffer), buffer);
 116                new_tree.push(fold, buffer);
 117            }
 118            new_tree.append(cursor.suffix(buffer), buffer);
 119            new_tree
 120        };
 121
 122        consolidate_inlay_edits(&mut edits);
 123        let edits = self.0.sync(snapshot.clone(), edits);
 124        (self.0.snapshot.clone(), edits)
 125    }
 126
 127    pub fn unfold<T: ToOffset>(
 128        &mut self,
 129        ranges: impl IntoIterator<Item = Range<T>>,
 130        inclusive: bool,
 131    ) -> (FoldSnapshot, Vec<FoldEdit>) {
 132        let mut edits = Vec::new();
 133        let mut fold_ixs_to_delete = Vec::new();
 134        let snapshot = self.0.snapshot.inlay_snapshot.clone();
 135        let buffer = &snapshot.buffer;
 136        for range in ranges.into_iter() {
 137            // Remove intersecting folds and add their ranges to edits that are passed to sync.
 138            let mut folds_cursor =
 139                intersecting_folds(&snapshot, &self.0.snapshot.folds, range, inclusive);
 140            while let Some(fold) = folds_cursor.item() {
 141                let offset_range = fold.0.start.to_offset(buffer)..fold.0.end.to_offset(buffer);
 142                if offset_range.end > offset_range.start {
 143                    let inlay_range = snapshot.to_inlay_offset(offset_range.start)
 144                        ..snapshot.to_inlay_offset(offset_range.end);
 145                    edits.push(InlayEdit {
 146                        old: inlay_range.clone(),
 147                        new: inlay_range,
 148                    });
 149                }
 150                fold_ixs_to_delete.push(*folds_cursor.start());
 151                folds_cursor.next(buffer);
 152            }
 153        }
 154
 155        fold_ixs_to_delete.sort_unstable();
 156        fold_ixs_to_delete.dedup();
 157
 158        self.0.snapshot.folds = {
 159            let mut cursor = self.0.snapshot.folds.cursor::<usize>();
 160            let mut folds = SumTree::new();
 161            for fold_ix in fold_ixs_to_delete {
 162                folds.append(cursor.slice(&fold_ix, Bias::Right, buffer), buffer);
 163                cursor.next(buffer);
 164            }
 165            folds.append(cursor.suffix(buffer), buffer);
 166            folds
 167        };
 168
 169        consolidate_inlay_edits(&mut edits);
 170        let edits = self.0.sync(snapshot.clone(), edits);
 171        (self.0.snapshot.clone(), edits)
 172    }
 173}
 174
 175pub struct FoldMap {
 176    snapshot: FoldSnapshot,
 177    ellipses_color: Option<Color>,
 178}
 179
 180impl FoldMap {
 181    pub fn new(inlay_snapshot: InlaySnapshot) -> (Self, FoldSnapshot) {
 182        let this = Self {
 183            snapshot: FoldSnapshot {
 184                folds: Default::default(),
 185                transforms: SumTree::from_item(
 186                    Transform {
 187                        summary: TransformSummary {
 188                            input: inlay_snapshot.text_summary(),
 189                            output: inlay_snapshot.text_summary(),
 190                        },
 191                        output_text: None,
 192                    },
 193                    &(),
 194                ),
 195                inlay_snapshot: inlay_snapshot.clone(),
 196                version: 0,
 197                ellipses_color: None,
 198            },
 199            ellipses_color: None,
 200        };
 201        let snapshot = this.snapshot.clone();
 202        (this, snapshot)
 203    }
 204
 205    pub fn read(
 206        &mut self,
 207        inlay_snapshot: InlaySnapshot,
 208        edits: Vec<InlayEdit>,
 209    ) -> (FoldSnapshot, Vec<FoldEdit>) {
 210        let edits = self.sync(inlay_snapshot, edits);
 211        self.check_invariants();
 212        (self.snapshot.clone(), edits)
 213    }
 214
 215    pub fn write(
 216        &mut self,
 217        inlay_snapshot: InlaySnapshot,
 218        edits: Vec<InlayEdit>,
 219    ) -> (FoldMapWriter, FoldSnapshot, Vec<FoldEdit>) {
 220        let (snapshot, edits) = self.read(inlay_snapshot, edits);
 221        (FoldMapWriter(self), snapshot, edits)
 222    }
 223
 224    pub fn set_ellipses_color(&mut self, color: Color) -> bool {
 225        if self.ellipses_color != Some(color) {
 226            self.ellipses_color = Some(color);
 227            true
 228        } else {
 229            false
 230        }
 231    }
 232
 233    fn check_invariants(&self) {
 234        if cfg!(test) {
 235            assert_eq!(
 236                self.snapshot.transforms.summary().input.len,
 237                self.snapshot.inlay_snapshot.len().0,
 238                "transform tree does not match inlay snapshot's length"
 239            );
 240
 241            let mut folds = self.snapshot.folds.iter().peekable();
 242            while let Some(fold) = folds.next() {
 243                if let Some(next_fold) = folds.peek() {
 244                    let comparison = fold
 245                        .0
 246                        .cmp(&next_fold.0, &self.snapshot.inlay_snapshot.buffer);
 247                    assert!(comparison.is_le());
 248                }
 249            }
 250        }
 251    }
 252
 253    fn sync(
 254        &mut self,
 255        inlay_snapshot: InlaySnapshot,
 256        inlay_edits: Vec<InlayEdit>,
 257    ) -> Vec<FoldEdit> {
 258        if inlay_edits.is_empty() {
 259            if self.snapshot.inlay_snapshot.version != inlay_snapshot.version {
 260                self.snapshot.version += 1;
 261            }
 262            self.snapshot.inlay_snapshot = inlay_snapshot;
 263            Vec::new()
 264        } else {
 265            let mut inlay_edits_iter = inlay_edits.iter().cloned().peekable();
 266
 267            let mut new_transforms = SumTree::new();
 268            let mut cursor = self.snapshot.transforms.cursor::<InlayOffset>();
 269            cursor.seek(&InlayOffset(0), Bias::Right, &());
 270
 271            while let Some(mut edit) = inlay_edits_iter.next() {
 272                new_transforms.append(cursor.slice(&edit.old.start, Bias::Left, &()), &());
 273                edit.new.start -= edit.old.start - *cursor.start();
 274                edit.old.start = *cursor.start();
 275
 276                cursor.seek(&edit.old.end, Bias::Right, &());
 277                cursor.next(&());
 278
 279                let mut delta = edit.new_len().0 as isize - edit.old_len().0 as isize;
 280                loop {
 281                    edit.old.end = *cursor.start();
 282
 283                    if let Some(next_edit) = inlay_edits_iter.peek() {
 284                        if next_edit.old.start > edit.old.end {
 285                            break;
 286                        }
 287
 288                        let next_edit = inlay_edits_iter.next().unwrap();
 289                        delta += next_edit.new_len().0 as isize - next_edit.old_len().0 as isize;
 290
 291                        if next_edit.old.end >= edit.old.end {
 292                            edit.old.end = next_edit.old.end;
 293                            cursor.seek(&edit.old.end, Bias::Right, &());
 294                            cursor.next(&());
 295                        }
 296                    } else {
 297                        break;
 298                    }
 299                }
 300
 301                edit.new.end =
 302                    InlayOffset(((edit.new.start + edit.old_len()).0 as isize + delta) as usize);
 303
 304                let anchor = inlay_snapshot
 305                    .buffer
 306                    .anchor_before(inlay_snapshot.to_buffer_offset(edit.new.start));
 307                let mut folds_cursor = self.snapshot.folds.cursor::<Fold>();
 308                folds_cursor.seek(
 309                    &Fold(anchor..Anchor::max()),
 310                    Bias::Left,
 311                    &inlay_snapshot.buffer,
 312                );
 313
 314                let mut folds = iter::from_fn({
 315                    let inlay_snapshot = &inlay_snapshot;
 316                    move || {
 317                        let item = folds_cursor.item().map(|f| {
 318                            let buffer_start = f.0.start.to_offset(&inlay_snapshot.buffer);
 319                            let buffer_end = f.0.end.to_offset(&inlay_snapshot.buffer);
 320                            inlay_snapshot.to_inlay_offset(buffer_start)
 321                                ..inlay_snapshot.to_inlay_offset(buffer_end)
 322                        });
 323                        folds_cursor.next(&inlay_snapshot.buffer);
 324                        item
 325                    }
 326                })
 327                .peekable();
 328
 329                while folds.peek().map_or(false, |fold| fold.start < edit.new.end) {
 330                    let mut fold = folds.next().unwrap();
 331                    let sum = new_transforms.summary();
 332
 333                    assert!(fold.start.0 >= sum.input.len);
 334
 335                    while folds
 336                        .peek()
 337                        .map_or(false, |next_fold| next_fold.start <= fold.end)
 338                    {
 339                        let next_fold = folds.next().unwrap();
 340                        if next_fold.end > fold.end {
 341                            fold.end = next_fold.end;
 342                        }
 343                    }
 344
 345                    if fold.start.0 > sum.input.len {
 346                        let text_summary = inlay_snapshot
 347                            .text_summary_for_range(InlayOffset(sum.input.len)..fold.start);
 348                        new_transforms.push(
 349                            Transform {
 350                                summary: TransformSummary {
 351                                    output: text_summary.clone(),
 352                                    input: text_summary,
 353                                },
 354                                output_text: None,
 355                            },
 356                            &(),
 357                        );
 358                    }
 359
 360                    if fold.end > fold.start {
 361                        let output_text = "";
 362                        new_transforms.push(
 363                            Transform {
 364                                summary: TransformSummary {
 365                                    output: TextSummary::from(output_text),
 366                                    input: inlay_snapshot
 367                                        .text_summary_for_range(fold.start..fold.end),
 368                                },
 369                                output_text: Some(output_text),
 370                            },
 371                            &(),
 372                        );
 373                    }
 374                }
 375
 376                let sum = new_transforms.summary();
 377                if sum.input.len < edit.new.end.0 {
 378                    let text_summary = inlay_snapshot
 379                        .text_summary_for_range(InlayOffset(sum.input.len)..edit.new.end);
 380                    new_transforms.push(
 381                        Transform {
 382                            summary: TransformSummary {
 383                                output: text_summary.clone(),
 384                                input: text_summary,
 385                            },
 386                            output_text: None,
 387                        },
 388                        &(),
 389                    );
 390                }
 391            }
 392
 393            new_transforms.append(cursor.suffix(&()), &());
 394            if new_transforms.is_empty() {
 395                let text_summary = inlay_snapshot.text_summary();
 396                new_transforms.push(
 397                    Transform {
 398                        summary: TransformSummary {
 399                            output: text_summary.clone(),
 400                            input: text_summary,
 401                        },
 402                        output_text: None,
 403                    },
 404                    &(),
 405                );
 406            }
 407
 408            drop(cursor);
 409
 410            let mut fold_edits = Vec::with_capacity(inlay_edits.len());
 411            {
 412                let mut old_transforms = self
 413                    .snapshot
 414                    .transforms
 415                    .cursor::<(InlayOffset, FoldOffset)>();
 416                let mut new_transforms = new_transforms.cursor::<(InlayOffset, FoldOffset)>();
 417
 418                for mut edit in inlay_edits {
 419                    old_transforms.seek(&edit.old.start, Bias::Left, &());
 420                    if old_transforms.item().map_or(false, |t| t.is_fold()) {
 421                        edit.old.start = old_transforms.start().0;
 422                    }
 423                    let old_start =
 424                        old_transforms.start().1 .0 + (edit.old.start - old_transforms.start().0).0;
 425
 426                    old_transforms.seek_forward(&edit.old.end, Bias::Right, &());
 427                    if old_transforms.item().map_or(false, |t| t.is_fold()) {
 428                        old_transforms.next(&());
 429                        edit.old.end = old_transforms.start().0;
 430                    }
 431                    let old_end =
 432                        old_transforms.start().1 .0 + (edit.old.end - old_transforms.start().0).0;
 433
 434                    new_transforms.seek(&edit.new.start, Bias::Left, &());
 435                    if new_transforms.item().map_or(false, |t| t.is_fold()) {
 436                        edit.new.start = new_transforms.start().0;
 437                    }
 438                    let new_start =
 439                        new_transforms.start().1 .0 + (edit.new.start - new_transforms.start().0).0;
 440
 441                    new_transforms.seek_forward(&edit.new.end, Bias::Right, &());
 442                    if new_transforms.item().map_or(false, |t| t.is_fold()) {
 443                        new_transforms.next(&());
 444                        edit.new.end = new_transforms.start().0;
 445                    }
 446                    let new_end =
 447                        new_transforms.start().1 .0 + (edit.new.end - new_transforms.start().0).0;
 448
 449                    fold_edits.push(FoldEdit {
 450                        old: FoldOffset(old_start)..FoldOffset(old_end),
 451                        new: FoldOffset(new_start)..FoldOffset(new_end),
 452                    });
 453                }
 454
 455                consolidate_fold_edits(&mut fold_edits);
 456            }
 457
 458            self.snapshot.transforms = new_transforms;
 459            self.snapshot.inlay_snapshot = inlay_snapshot;
 460            self.snapshot.version += 1;
 461            fold_edits
 462        }
 463    }
 464}
 465
 466#[derive(Clone)]
 467pub struct FoldSnapshot {
 468    transforms: SumTree<Transform>,
 469    folds: SumTree<Fold>,
 470    pub inlay_snapshot: InlaySnapshot,
 471    pub version: usize,
 472    pub ellipses_color: Option<Color>,
 473}
 474
 475impl FoldSnapshot {
 476    #[cfg(test)]
 477    pub fn text(&self) -> String {
 478        self.chunks(FoldOffset(0)..self.len(), false, None, None)
 479            .map(|c| c.text)
 480            .collect()
 481    }
 482
 483    #[cfg(test)]
 484    pub fn fold_count(&self) -> usize {
 485        self.folds.items(&self.inlay_snapshot.buffer).len()
 486    }
 487
 488    pub fn text_summary_for_range(&self, range: Range<FoldPoint>) -> TextSummary {
 489        let mut summary = TextSummary::default();
 490
 491        let mut cursor = self.transforms.cursor::<(FoldPoint, InlayPoint)>();
 492        cursor.seek(&range.start, Bias::Right, &());
 493        if let Some(transform) = cursor.item() {
 494            let start_in_transform = range.start.0 - cursor.start().0 .0;
 495            let end_in_transform = cmp::min(range.end, cursor.end(&()).0).0 - cursor.start().0 .0;
 496            if let Some(output_text) = transform.output_text {
 497                summary = TextSummary::from(
 498                    &output_text
 499                        [start_in_transform.column as usize..end_in_transform.column as usize],
 500                );
 501            } else {
 502                let inlay_start = self
 503                    .inlay_snapshot
 504                    .to_offset(InlayPoint(cursor.start().1 .0 + start_in_transform));
 505                let inlay_end = self
 506                    .inlay_snapshot
 507                    .to_offset(InlayPoint(cursor.start().1 .0 + end_in_transform));
 508                summary = self
 509                    .inlay_snapshot
 510                    .text_summary_for_range(inlay_start..inlay_end);
 511            }
 512        }
 513
 514        if range.end > cursor.end(&()).0 {
 515            cursor.next(&());
 516            summary += &cursor
 517                .summary::<_, TransformSummary>(&range.end, Bias::Right, &())
 518                .output;
 519            if let Some(transform) = cursor.item() {
 520                let end_in_transform = range.end.0 - cursor.start().0 .0;
 521                if let Some(output_text) = transform.output_text {
 522                    summary += TextSummary::from(&output_text[..end_in_transform.column as usize]);
 523                } else {
 524                    let inlay_start = self.inlay_snapshot.to_offset(cursor.start().1);
 525                    let inlay_end = self
 526                        .inlay_snapshot
 527                        .to_offset(InlayPoint(cursor.start().1 .0 + end_in_transform));
 528                    summary += self
 529                        .inlay_snapshot
 530                        .text_summary_for_range(inlay_start..inlay_end);
 531                }
 532            }
 533        }
 534
 535        summary
 536    }
 537
 538    pub fn to_fold_point(&self, point: InlayPoint, bias: Bias) -> FoldPoint {
 539        let mut cursor = self.transforms.cursor::<(InlayPoint, FoldPoint)>();
 540        cursor.seek(&point, Bias::Right, &());
 541        if cursor.item().map_or(false, |t| t.is_fold()) {
 542            if bias == Bias::Left || point == cursor.start().0 {
 543                cursor.start().1
 544            } else {
 545                cursor.end(&()).1
 546            }
 547        } else {
 548            let overshoot = point.0 - cursor.start().0 .0;
 549            FoldPoint(cmp::min(
 550                cursor.start().1 .0 + overshoot,
 551                cursor.end(&()).1 .0,
 552            ))
 553        }
 554    }
 555
 556    pub fn len(&self) -> FoldOffset {
 557        FoldOffset(self.transforms.summary().output.len)
 558    }
 559
 560    pub fn line_len(&self, row: u32) -> u32 {
 561        let line_start = FoldPoint::new(row, 0).to_offset(self).0;
 562        let line_end = if row >= self.max_point().row() {
 563            self.len().0
 564        } else {
 565            FoldPoint::new(row + 1, 0).to_offset(self).0 - 1
 566        };
 567        (line_end - line_start) as u32
 568    }
 569
 570    pub fn buffer_rows(&self, start_row: u32) -> FoldBufferRows {
 571        if start_row > self.transforms.summary().output.lines.row {
 572            panic!("invalid display row {}", start_row);
 573        }
 574
 575        let fold_point = FoldPoint::new(start_row, 0);
 576        let mut cursor = self.transforms.cursor::<(FoldPoint, InlayPoint)>();
 577        cursor.seek(&fold_point, Bias::Left, &());
 578
 579        let overshoot = fold_point.0 - cursor.start().0 .0;
 580        let inlay_point = InlayPoint(cursor.start().1 .0 + overshoot);
 581        let input_buffer_rows = self.inlay_snapshot.buffer_rows(inlay_point.row());
 582
 583        FoldBufferRows {
 584            fold_point,
 585            input_buffer_rows,
 586            cursor,
 587        }
 588    }
 589
 590    pub fn max_point(&self) -> FoldPoint {
 591        FoldPoint(self.transforms.summary().output.lines)
 592    }
 593
 594    #[cfg(test)]
 595    pub fn longest_row(&self) -> u32 {
 596        self.transforms.summary().output.longest_row
 597    }
 598
 599    pub fn folds_in_range<T>(&self, range: Range<T>) -> impl Iterator<Item = &Range<Anchor>>
 600    where
 601        T: ToOffset,
 602    {
 603        let mut folds = intersecting_folds(&self.inlay_snapshot, &self.folds, range, false);
 604        iter::from_fn(move || {
 605            let item = folds.item().map(|f| &f.0);
 606            folds.next(&self.inlay_snapshot.buffer);
 607            item
 608        })
 609    }
 610
 611    pub fn intersects_fold<T>(&self, offset: T) -> bool
 612    where
 613        T: ToOffset,
 614    {
 615        let buffer_offset = offset.to_offset(&self.inlay_snapshot.buffer);
 616        let inlay_offset = self.inlay_snapshot.to_inlay_offset(buffer_offset);
 617        let mut cursor = self.transforms.cursor::<InlayOffset>();
 618        cursor.seek(&inlay_offset, Bias::Right, &());
 619        cursor.item().map_or(false, |t| t.output_text.is_some())
 620    }
 621
 622    pub fn is_line_folded(&self, buffer_row: u32) -> bool {
 623        let mut inlay_point = self
 624            .inlay_snapshot
 625            .to_inlay_point(Point::new(buffer_row, 0));
 626        let mut cursor = self.transforms.cursor::<InlayPoint>();
 627        cursor.seek(&inlay_point, Bias::Right, &());
 628        loop {
 629            match cursor.item() {
 630                Some(transform) => {
 631                    let buffer_point = self.inlay_snapshot.to_buffer_point(inlay_point);
 632                    if buffer_point.row != buffer_row {
 633                        return false;
 634                    } else if transform.output_text.is_some() {
 635                        return true;
 636                    }
 637                }
 638                None => return false,
 639            }
 640
 641            if cursor.end(&()).row() == inlay_point.row() {
 642                cursor.next(&());
 643            } else {
 644                inlay_point.0 += Point::new(1, 0);
 645                cursor.seek(&inlay_point, Bias::Right, &());
 646            }
 647        }
 648    }
 649
 650    pub fn chunks<'a>(
 651        &'a self,
 652        range: Range<FoldOffset>,
 653        language_aware: bool,
 654        text_highlights: Option<&'a TextHighlights>,
 655        inlay_highlights: Option<HighlightStyle>,
 656    ) -> FoldChunks<'a> {
 657        let mut transform_cursor = self.transforms.cursor::<(FoldOffset, InlayOffset)>();
 658
 659        let inlay_end = {
 660            transform_cursor.seek(&range.end, Bias::Right, &());
 661            let overshoot = range.end.0 - transform_cursor.start().0 .0;
 662            transform_cursor.start().1 + InlayOffset(overshoot)
 663        };
 664
 665        let inlay_start = {
 666            transform_cursor.seek(&range.start, Bias::Right, &());
 667            let overshoot = range.start.0 - transform_cursor.start().0 .0;
 668            transform_cursor.start().1 + InlayOffset(overshoot)
 669        };
 670
 671        FoldChunks {
 672            transform_cursor,
 673            inlay_chunks: self.inlay_snapshot.chunks(
 674                inlay_start..inlay_end,
 675                language_aware,
 676                text_highlights,
 677                inlay_highlights,
 678            ),
 679            inlay_chunk: None,
 680            inlay_offset: inlay_start,
 681            output_offset: range.start.0,
 682            max_output_offset: range.end.0,
 683            ellipses_color: self.ellipses_color,
 684        }
 685    }
 686
 687    pub fn chars_at(&self, start: FoldPoint) -> impl '_ + Iterator<Item = char> {
 688        self.chunks(start.to_offset(self)..self.len(), false, None, None)
 689            .flat_map(|chunk| chunk.text.chars())
 690    }
 691
 692    #[cfg(test)]
 693    pub fn clip_offset(&self, offset: FoldOffset, bias: Bias) -> FoldOffset {
 694        if offset > self.len() {
 695            self.len()
 696        } else {
 697            self.clip_point(offset.to_point(self), bias).to_offset(self)
 698        }
 699    }
 700
 701    pub fn clip_point(&self, point: FoldPoint, bias: Bias) -> FoldPoint {
 702        let mut cursor = self.transforms.cursor::<(FoldPoint, InlayPoint)>();
 703        cursor.seek(&point, Bias::Right, &());
 704        if let Some(transform) = cursor.item() {
 705            let transform_start = cursor.start().0 .0;
 706            if transform.output_text.is_some() {
 707                if point.0 == transform_start || matches!(bias, Bias::Left) {
 708                    FoldPoint(transform_start)
 709                } else {
 710                    FoldPoint(cursor.end(&()).0 .0)
 711                }
 712            } else {
 713                let overshoot = InlayPoint(point.0 - transform_start);
 714                let inlay_point = cursor.start().1 + overshoot;
 715                let clipped_inlay_point = self.inlay_snapshot.clip_point(inlay_point, bias);
 716                FoldPoint(cursor.start().0 .0 + (clipped_inlay_point - cursor.start().1).0)
 717            }
 718        } else {
 719            FoldPoint(self.transforms.summary().output.lines)
 720        }
 721    }
 722}
 723
 724fn intersecting_folds<'a, T>(
 725    inlay_snapshot: &'a InlaySnapshot,
 726    folds: &'a SumTree<Fold>,
 727    range: Range<T>,
 728    inclusive: bool,
 729) -> FilterCursor<'a, impl 'a + FnMut(&FoldSummary) -> bool, Fold, usize>
 730where
 731    T: ToOffset,
 732{
 733    let buffer = &inlay_snapshot.buffer;
 734    let start = buffer.anchor_before(range.start.to_offset(buffer));
 735    let end = buffer.anchor_after(range.end.to_offset(buffer));
 736    let mut cursor = folds.filter::<_, usize>(move |summary| {
 737        let start_cmp = start.cmp(&summary.max_end, buffer);
 738        let end_cmp = end.cmp(&summary.min_start, buffer);
 739
 740        if inclusive {
 741            start_cmp <= Ordering::Equal && end_cmp >= Ordering::Equal
 742        } else {
 743            start_cmp == Ordering::Less && end_cmp == Ordering::Greater
 744        }
 745    });
 746    cursor.next(buffer);
 747    cursor
 748}
 749
 750fn consolidate_inlay_edits(edits: &mut Vec<InlayEdit>) {
 751    edits.sort_unstable_by(|a, b| {
 752        a.old
 753            .start
 754            .cmp(&b.old.start)
 755            .then_with(|| b.old.end.cmp(&a.old.end))
 756    });
 757
 758    let mut i = 1;
 759    while i < edits.len() {
 760        let edit = edits[i].clone();
 761        let prev_edit = &mut edits[i - 1];
 762        if prev_edit.old.end >= edit.old.start {
 763            prev_edit.old.end = prev_edit.old.end.max(edit.old.end);
 764            prev_edit.new.start = prev_edit.new.start.min(edit.new.start);
 765            prev_edit.new.end = prev_edit.new.end.max(edit.new.end);
 766            edits.remove(i);
 767            continue;
 768        }
 769        i += 1;
 770    }
 771}
 772
 773fn consolidate_fold_edits(edits: &mut Vec<FoldEdit>) {
 774    edits.sort_unstable_by(|a, b| {
 775        a.old
 776            .start
 777            .cmp(&b.old.start)
 778            .then_with(|| b.old.end.cmp(&a.old.end))
 779    });
 780
 781    let mut i = 1;
 782    while i < edits.len() {
 783        let edit = edits[i].clone();
 784        let prev_edit = &mut edits[i - 1];
 785        if prev_edit.old.end >= edit.old.start {
 786            prev_edit.old.end = prev_edit.old.end.max(edit.old.end);
 787            prev_edit.new.start = prev_edit.new.start.min(edit.new.start);
 788            prev_edit.new.end = prev_edit.new.end.max(edit.new.end);
 789            edits.remove(i);
 790            continue;
 791        }
 792        i += 1;
 793    }
 794}
 795
 796#[derive(Clone, Debug, Default, Eq, PartialEq)]
 797struct Transform {
 798    summary: TransformSummary,
 799    output_text: Option<&'static str>,
 800}
 801
 802impl Transform {
 803    fn is_fold(&self) -> bool {
 804        self.output_text.is_some()
 805    }
 806}
 807
 808#[derive(Clone, Debug, Default, Eq, PartialEq)]
 809struct TransformSummary {
 810    output: TextSummary,
 811    input: TextSummary,
 812}
 813
 814impl sum_tree::Item for Transform {
 815    type Summary = TransformSummary;
 816
 817    fn summary(&self) -> Self::Summary {
 818        self.summary.clone()
 819    }
 820}
 821
 822impl sum_tree::Summary for TransformSummary {
 823    type Context = ();
 824
 825    fn add_summary(&mut self, other: &Self, _: &()) {
 826        self.input += &other.input;
 827        self.output += &other.output;
 828    }
 829}
 830
 831#[derive(Clone, Debug)]
 832struct Fold(Range<Anchor>);
 833
 834impl Default for Fold {
 835    fn default() -> Self {
 836        Self(Anchor::min()..Anchor::max())
 837    }
 838}
 839
 840impl sum_tree::Item for Fold {
 841    type Summary = FoldSummary;
 842
 843    fn summary(&self) -> Self::Summary {
 844        FoldSummary {
 845            start: self.0.start.clone(),
 846            end: self.0.end.clone(),
 847            min_start: self.0.start.clone(),
 848            max_end: self.0.end.clone(),
 849            count: 1,
 850        }
 851    }
 852}
 853
 854#[derive(Clone, Debug)]
 855struct FoldSummary {
 856    start: Anchor,
 857    end: Anchor,
 858    min_start: Anchor,
 859    max_end: Anchor,
 860    count: usize,
 861}
 862
 863impl Default for FoldSummary {
 864    fn default() -> Self {
 865        Self {
 866            start: Anchor::min(),
 867            end: Anchor::max(),
 868            min_start: Anchor::max(),
 869            max_end: Anchor::min(),
 870            count: 0,
 871        }
 872    }
 873}
 874
 875impl sum_tree::Summary for FoldSummary {
 876    type Context = MultiBufferSnapshot;
 877
 878    fn add_summary(&mut self, other: &Self, buffer: &Self::Context) {
 879        if other.min_start.cmp(&self.min_start, buffer) == Ordering::Less {
 880            self.min_start = other.min_start.clone();
 881        }
 882        if other.max_end.cmp(&self.max_end, buffer) == Ordering::Greater {
 883            self.max_end = other.max_end.clone();
 884        }
 885
 886        #[cfg(debug_assertions)]
 887        {
 888            let start_comparison = self.start.cmp(&other.start, buffer);
 889            assert!(start_comparison <= Ordering::Equal);
 890            if start_comparison == Ordering::Equal {
 891                assert!(self.end.cmp(&other.end, buffer) >= Ordering::Equal);
 892            }
 893        }
 894
 895        self.start = other.start.clone();
 896        self.end = other.end.clone();
 897        self.count += other.count;
 898    }
 899}
 900
 901impl<'a> sum_tree::Dimension<'a, FoldSummary> for Fold {
 902    fn add_summary(&mut self, summary: &'a FoldSummary, _: &MultiBufferSnapshot) {
 903        self.0.start = summary.start.clone();
 904        self.0.end = summary.end.clone();
 905    }
 906}
 907
 908impl<'a> sum_tree::SeekTarget<'a, FoldSummary, Fold> for Fold {
 909    fn cmp(&self, other: &Self, buffer: &MultiBufferSnapshot) -> Ordering {
 910        self.0.cmp(&other.0, buffer)
 911    }
 912}
 913
 914impl<'a> sum_tree::Dimension<'a, FoldSummary> for usize {
 915    fn add_summary(&mut self, summary: &'a FoldSummary, _: &MultiBufferSnapshot) {
 916        *self += summary.count;
 917    }
 918}
 919
 920#[derive(Clone)]
 921pub struct FoldBufferRows<'a> {
 922    cursor: Cursor<'a, Transform, (FoldPoint, InlayPoint)>,
 923    input_buffer_rows: InlayBufferRows<'a>,
 924    fold_point: FoldPoint,
 925}
 926
 927impl<'a> Iterator for FoldBufferRows<'a> {
 928    type Item = Option<u32>;
 929
 930    fn next(&mut self) -> Option<Self::Item> {
 931        let mut traversed_fold = false;
 932        while self.fold_point > self.cursor.end(&()).0 {
 933            self.cursor.next(&());
 934            traversed_fold = true;
 935            if self.cursor.item().is_none() {
 936                break;
 937            }
 938        }
 939
 940        if self.cursor.item().is_some() {
 941            if traversed_fold {
 942                self.input_buffer_rows.seek(self.cursor.start().1.row());
 943                self.input_buffer_rows.next();
 944            }
 945            *self.fold_point.row_mut() += 1;
 946            self.input_buffer_rows.next()
 947        } else {
 948            None
 949        }
 950    }
 951}
 952
 953pub struct FoldChunks<'a> {
 954    transform_cursor: Cursor<'a, Transform, (FoldOffset, InlayOffset)>,
 955    inlay_chunks: InlayChunks<'a>,
 956    inlay_chunk: Option<(InlayOffset, Chunk<'a>)>,
 957    inlay_offset: InlayOffset,
 958    output_offset: usize,
 959    max_output_offset: usize,
 960    ellipses_color: Option<Color>,
 961}
 962
 963impl<'a> Iterator for FoldChunks<'a> {
 964    type Item = Chunk<'a>;
 965
 966    fn next(&mut self) -> Option<Self::Item> {
 967        if self.output_offset >= self.max_output_offset {
 968            return None;
 969        }
 970
 971        let transform = self.transform_cursor.item()?;
 972
 973        // If we're in a fold, then return the fold's display text and
 974        // advance the transform and buffer cursors to the end of the fold.
 975        if let Some(output_text) = transform.output_text {
 976            self.inlay_chunk.take();
 977            self.inlay_offset += InlayOffset(transform.summary.input.len);
 978            self.inlay_chunks.seek(self.inlay_offset);
 979
 980            while self.inlay_offset >= self.transform_cursor.end(&()).1
 981                && self.transform_cursor.item().is_some()
 982            {
 983                self.transform_cursor.next(&());
 984            }
 985
 986            self.output_offset += output_text.len();
 987            return Some(Chunk {
 988                text: output_text,
 989                highlight_style: self.ellipses_color.map(|color| HighlightStyle {
 990                    color: Some(color),
 991                    ..Default::default()
 992                }),
 993                ..Default::default()
 994            });
 995        }
 996
 997        // Retrieve a chunk from the current location in the buffer.
 998        if self.inlay_chunk.is_none() {
 999            let chunk_offset = self.inlay_chunks.offset();
1000            self.inlay_chunk = self.inlay_chunks.next().map(|chunk| (chunk_offset, chunk));
1001        }
1002
1003        // Otherwise, take a chunk from the buffer's text.
1004        if let Some((buffer_chunk_start, mut chunk)) = self.inlay_chunk {
1005            let buffer_chunk_end = buffer_chunk_start + InlayOffset(chunk.text.len());
1006            let transform_end = self.transform_cursor.end(&()).1;
1007            let chunk_end = buffer_chunk_end.min(transform_end);
1008
1009            chunk.text = &chunk.text
1010                [(self.inlay_offset - buffer_chunk_start).0..(chunk_end - buffer_chunk_start).0];
1011
1012            if chunk_end == transform_end {
1013                self.transform_cursor.next(&());
1014            } else if chunk_end == buffer_chunk_end {
1015                self.inlay_chunk.take();
1016            }
1017
1018            self.inlay_offset = chunk_end;
1019            self.output_offset += chunk.text.len();
1020            return Some(chunk);
1021        }
1022
1023        None
1024    }
1025}
1026
1027#[derive(Copy, Clone, Eq, PartialEq)]
1028struct HighlightEndpoint {
1029    offset: InlayOffset,
1030    is_start: bool,
1031    tag: Option<TypeId>,
1032    style: HighlightStyle,
1033}
1034
1035impl PartialOrd for HighlightEndpoint {
1036    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
1037        Some(self.cmp(other))
1038    }
1039}
1040
1041impl Ord for HighlightEndpoint {
1042    fn cmp(&self, other: &Self) -> Ordering {
1043        self.offset
1044            .cmp(&other.offset)
1045            .then_with(|| other.is_start.cmp(&self.is_start))
1046    }
1047}
1048
1049#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
1050pub struct FoldOffset(pub usize);
1051
1052impl FoldOffset {
1053    pub fn to_point(self, snapshot: &FoldSnapshot) -> FoldPoint {
1054        let mut cursor = snapshot
1055            .transforms
1056            .cursor::<(FoldOffset, TransformSummary)>();
1057        cursor.seek(&self, Bias::Right, &());
1058        let overshoot = if cursor.item().map_or(true, |t| t.is_fold()) {
1059            Point::new(0, (self.0 - cursor.start().0 .0) as u32)
1060        } else {
1061            let inlay_offset = cursor.start().1.input.len + self.0 - cursor.start().0 .0;
1062            let inlay_point = snapshot.inlay_snapshot.to_point(InlayOffset(inlay_offset));
1063            inlay_point.0 - cursor.start().1.input.lines
1064        };
1065        FoldPoint(cursor.start().1.output.lines + overshoot)
1066    }
1067
1068    #[cfg(test)]
1069    pub fn to_inlay_offset(self, snapshot: &FoldSnapshot) -> InlayOffset {
1070        let mut cursor = snapshot.transforms.cursor::<(FoldOffset, InlayOffset)>();
1071        cursor.seek(&self, Bias::Right, &());
1072        let overshoot = self.0 - cursor.start().0 .0;
1073        InlayOffset(cursor.start().1 .0 + overshoot)
1074    }
1075}
1076
1077impl Add for FoldOffset {
1078    type Output = Self;
1079
1080    fn add(self, rhs: Self) -> Self::Output {
1081        Self(self.0 + rhs.0)
1082    }
1083}
1084
1085impl AddAssign for FoldOffset {
1086    fn add_assign(&mut self, rhs: Self) {
1087        self.0 += rhs.0;
1088    }
1089}
1090
1091impl Sub for FoldOffset {
1092    type Output = Self;
1093
1094    fn sub(self, rhs: Self) -> Self::Output {
1095        Self(self.0 - rhs.0)
1096    }
1097}
1098
1099impl<'a> sum_tree::Dimension<'a, TransformSummary> for FoldOffset {
1100    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1101        self.0 += &summary.output.len;
1102    }
1103}
1104
1105impl<'a> sum_tree::Dimension<'a, TransformSummary> for InlayPoint {
1106    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1107        self.0 += &summary.input.lines;
1108    }
1109}
1110
1111impl<'a> sum_tree::Dimension<'a, TransformSummary> for InlayOffset {
1112    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1113        self.0 += &summary.input.len;
1114    }
1115}
1116
1117pub type FoldEdit = Edit<FoldOffset>;
1118
1119#[cfg(test)]
1120mod tests {
1121    use super::*;
1122    use crate::{display_map::inlay_map::InlayMap, MultiBuffer, ToPoint};
1123    use collections::HashSet;
1124    use rand::prelude::*;
1125    use settings::SettingsStore;
1126    use std::{cmp::Reverse, env, mem, sync::Arc};
1127    use sum_tree::TreeMap;
1128    use text::Patch;
1129    use util::test::sample_text;
1130    use util::RandomCharIter;
1131    use Bias::{Left, Right};
1132
1133    #[gpui::test]
1134    fn test_basic_folds(cx: &mut gpui::AppContext) {
1135        init_test(cx);
1136        let buffer = MultiBuffer::build_simple(&sample_text(5, 6, 'a'), cx);
1137        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
1138        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1139        let (mut inlay_map, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1140        let mut map = FoldMap::new(inlay_snapshot.clone()).0;
1141
1142        let (mut writer, _, _) = map.write(inlay_snapshot, vec![]);
1143        let (snapshot2, edits) = writer.fold(vec![
1144            Point::new(0, 2)..Point::new(2, 2),
1145            Point::new(2, 4)..Point::new(4, 1),
1146        ]);
1147        assert_eq!(snapshot2.text(), "aa⋯cc⋯eeeee");
1148        assert_eq!(
1149            edits,
1150            &[
1151                FoldEdit {
1152                    old: FoldOffset(2)..FoldOffset(16),
1153                    new: FoldOffset(2)..FoldOffset(5),
1154                },
1155                FoldEdit {
1156                    old: FoldOffset(18)..FoldOffset(29),
1157                    new: FoldOffset(7)..FoldOffset(10)
1158                },
1159            ]
1160        );
1161
1162        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1163            buffer.edit(
1164                vec![
1165                    (Point::new(0, 0)..Point::new(0, 1), "123"),
1166                    (Point::new(2, 3)..Point::new(2, 3), "123"),
1167                ],
1168                None,
1169                cx,
1170            );
1171            buffer.snapshot(cx)
1172        });
1173
1174        let (inlay_snapshot, inlay_edits) =
1175            inlay_map.sync(buffer_snapshot, subscription.consume().into_inner());
1176        let (snapshot3, edits) = map.read(inlay_snapshot, inlay_edits);
1177        assert_eq!(snapshot3.text(), "123a⋯c123c⋯eeeee");
1178        assert_eq!(
1179            edits,
1180            &[
1181                FoldEdit {
1182                    old: FoldOffset(0)..FoldOffset(1),
1183                    new: FoldOffset(0)..FoldOffset(3),
1184                },
1185                FoldEdit {
1186                    old: FoldOffset(6)..FoldOffset(6),
1187                    new: FoldOffset(8)..FoldOffset(11),
1188                },
1189            ]
1190        );
1191
1192        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1193            buffer.edit([(Point::new(2, 6)..Point::new(4, 3), "456")], None, cx);
1194            buffer.snapshot(cx)
1195        });
1196        let (inlay_snapshot, inlay_edits) =
1197            inlay_map.sync(buffer_snapshot, subscription.consume().into_inner());
1198        let (snapshot4, _) = map.read(inlay_snapshot.clone(), inlay_edits);
1199        assert_eq!(snapshot4.text(), "123a⋯c123456eee");
1200
1201        let (mut writer, _, _) = map.write(inlay_snapshot.clone(), vec![]);
1202        writer.unfold(Some(Point::new(0, 4)..Point::new(0, 4)), false);
1203        let (snapshot5, _) = map.read(inlay_snapshot.clone(), vec![]);
1204        assert_eq!(snapshot5.text(), "123a⋯c123456eee");
1205
1206        let (mut writer, _, _) = map.write(inlay_snapshot.clone(), vec![]);
1207        writer.unfold(Some(Point::new(0, 4)..Point::new(0, 4)), true);
1208        let (snapshot6, _) = map.read(inlay_snapshot, vec![]);
1209        assert_eq!(snapshot6.text(), "123aaaaa\nbbbbbb\nccc123456eee");
1210    }
1211
1212    #[gpui::test]
1213    fn test_adjacent_folds(cx: &mut gpui::AppContext) {
1214        init_test(cx);
1215        let buffer = MultiBuffer::build_simple("abcdefghijkl", cx);
1216        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
1217        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1218        let (mut inlay_map, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1219
1220        {
1221            let mut map = FoldMap::new(inlay_snapshot.clone()).0;
1222
1223            let (mut writer, _, _) = map.write(inlay_snapshot.clone(), vec![]);
1224            writer.fold(vec![5..8]);
1225            let (snapshot, _) = map.read(inlay_snapshot.clone(), vec![]);
1226            assert_eq!(snapshot.text(), "abcde⋯ijkl");
1227
1228            // Create an fold adjacent to the start of the first fold.
1229            let (mut writer, _, _) = map.write(inlay_snapshot.clone(), vec![]);
1230            writer.fold(vec![0..1, 2..5]);
1231            let (snapshot, _) = map.read(inlay_snapshot.clone(), vec![]);
1232            assert_eq!(snapshot.text(), "⋯b⋯ijkl");
1233
1234            // Create an fold adjacent to the end of the first fold.
1235            let (mut writer, _, _) = map.write(inlay_snapshot.clone(), vec![]);
1236            writer.fold(vec![11..11, 8..10]);
1237            let (snapshot, _) = map.read(inlay_snapshot.clone(), vec![]);
1238            assert_eq!(snapshot.text(), "⋯b⋯kl");
1239        }
1240
1241        {
1242            let mut map = FoldMap::new(inlay_snapshot.clone()).0;
1243
1244            // Create two adjacent folds.
1245            let (mut writer, _, _) = map.write(inlay_snapshot.clone(), vec![]);
1246            writer.fold(vec![0..2, 2..5]);
1247            let (snapshot, _) = map.read(inlay_snapshot, vec![]);
1248            assert_eq!(snapshot.text(), "⋯fghijkl");
1249
1250            // Edit within one of the folds.
1251            let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1252                buffer.edit([(0..1, "12345")], None, cx);
1253                buffer.snapshot(cx)
1254            });
1255            let (inlay_snapshot, inlay_edits) =
1256                inlay_map.sync(buffer_snapshot, subscription.consume().into_inner());
1257            let (snapshot, _) = map.read(inlay_snapshot, inlay_edits);
1258            assert_eq!(snapshot.text(), "12345⋯fghijkl");
1259        }
1260    }
1261
1262    #[gpui::test]
1263    fn test_overlapping_folds(cx: &mut gpui::AppContext) {
1264        let buffer = MultiBuffer::build_simple(&sample_text(5, 6, 'a'), cx);
1265        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1266        let (_, inlay_snapshot) = InlayMap::new(buffer_snapshot);
1267        let mut map = FoldMap::new(inlay_snapshot.clone()).0;
1268        let (mut writer, _, _) = map.write(inlay_snapshot.clone(), vec![]);
1269        writer.fold(vec![
1270            Point::new(0, 2)..Point::new(2, 2),
1271            Point::new(0, 4)..Point::new(1, 0),
1272            Point::new(1, 2)..Point::new(3, 2),
1273            Point::new(3, 1)..Point::new(4, 1),
1274        ]);
1275        let (snapshot, _) = map.read(inlay_snapshot, vec![]);
1276        assert_eq!(snapshot.text(), "aa⋯eeeee");
1277    }
1278
1279    #[gpui::test]
1280    fn test_merging_folds_via_edit(cx: &mut gpui::AppContext) {
1281        init_test(cx);
1282        let buffer = MultiBuffer::build_simple(&sample_text(5, 6, 'a'), cx);
1283        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
1284        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1285        let (mut inlay_map, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1286        let mut map = FoldMap::new(inlay_snapshot.clone()).0;
1287
1288        let (mut writer, _, _) = map.write(inlay_snapshot.clone(), vec![]);
1289        writer.fold(vec![
1290            Point::new(0, 2)..Point::new(2, 2),
1291            Point::new(3, 1)..Point::new(4, 1),
1292        ]);
1293        let (snapshot, _) = map.read(inlay_snapshot.clone(), vec![]);
1294        assert_eq!(snapshot.text(), "aa⋯cccc\nd⋯eeeee");
1295
1296        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1297            buffer.edit([(Point::new(2, 2)..Point::new(3, 1), "")], None, cx);
1298            buffer.snapshot(cx)
1299        });
1300        let (inlay_snapshot, inlay_edits) =
1301            inlay_map.sync(buffer_snapshot, subscription.consume().into_inner());
1302        let (snapshot, _) = map.read(inlay_snapshot, inlay_edits);
1303        assert_eq!(snapshot.text(), "aa⋯eeeee");
1304    }
1305
1306    #[gpui::test]
1307    fn test_folds_in_range(cx: &mut gpui::AppContext) {
1308        let buffer = MultiBuffer::build_simple(&sample_text(5, 6, 'a'), cx);
1309        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1310        let (_, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1311        let mut map = FoldMap::new(inlay_snapshot.clone()).0;
1312
1313        let (mut writer, _, _) = map.write(inlay_snapshot.clone(), vec![]);
1314        writer.fold(vec![
1315            Point::new(0, 2)..Point::new(2, 2),
1316            Point::new(0, 4)..Point::new(1, 0),
1317            Point::new(1, 2)..Point::new(3, 2),
1318            Point::new(3, 1)..Point::new(4, 1),
1319        ]);
1320        let (snapshot, _) = map.read(inlay_snapshot.clone(), vec![]);
1321        let fold_ranges = snapshot
1322            .folds_in_range(Point::new(1, 0)..Point::new(1, 3))
1323            .map(|fold| fold.start.to_point(&buffer_snapshot)..fold.end.to_point(&buffer_snapshot))
1324            .collect::<Vec<_>>();
1325        assert_eq!(
1326            fold_ranges,
1327            vec![
1328                Point::new(0, 2)..Point::new(2, 2),
1329                Point::new(1, 2)..Point::new(3, 2)
1330            ]
1331        );
1332    }
1333
1334    #[gpui::test(iterations = 100)]
1335    fn test_random_folds(cx: &mut gpui::AppContext, mut rng: StdRng) {
1336        init_test(cx);
1337        let operations = env::var("OPERATIONS")
1338            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1339            .unwrap_or(10);
1340
1341        let len = rng.gen_range(0..10);
1342        let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1343        let buffer = if rng.gen() {
1344            MultiBuffer::build_simple(&text, cx)
1345        } else {
1346            MultiBuffer::build_random(&mut rng, cx)
1347        };
1348        let mut buffer_snapshot = buffer.read(cx).snapshot(cx);
1349        let (mut inlay_map, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1350        let mut map = FoldMap::new(inlay_snapshot.clone()).0;
1351
1352        let (mut initial_snapshot, _) = map.read(inlay_snapshot.clone(), vec![]);
1353        let mut snapshot_edits = Vec::new();
1354
1355        let mut highlights = TreeMap::default();
1356        let highlight_count = rng.gen_range(0_usize..10);
1357        let mut highlight_ranges = (0..highlight_count)
1358            .map(|_| buffer_snapshot.random_byte_range(0, &mut rng))
1359            .collect::<Vec<_>>();
1360        highlight_ranges.sort_by_key(|range| (range.start, Reverse(range.end)));
1361        log::info!("highlighting ranges {:?}", highlight_ranges);
1362        let highlight_ranges = highlight_ranges
1363            .into_iter()
1364            .map(|range| {
1365                buffer_snapshot.anchor_before(range.start)..buffer_snapshot.anchor_after(range.end)
1366            })
1367            .collect::<Vec<_>>();
1368
1369        highlights.insert(
1370            Some(TypeId::of::<()>()),
1371            Arc::new((HighlightStyle::default(), highlight_ranges)),
1372        );
1373
1374        let mut next_inlay_id = 0;
1375        for _ in 0..operations {
1376            log::info!("text: {:?}", buffer_snapshot.text());
1377            let mut buffer_edits = Vec::new();
1378            let mut inlay_edits = Vec::new();
1379            match rng.gen_range(0..=100) {
1380                0..=39 => {
1381                    snapshot_edits.extend(map.randomly_mutate(&mut rng));
1382                }
1383                40..=59 => {
1384                    let (_, edits) = inlay_map.randomly_mutate(&mut next_inlay_id, &mut rng);
1385                    inlay_edits = edits;
1386                }
1387                _ => buffer.update(cx, |buffer, cx| {
1388                    let subscription = buffer.subscribe();
1389                    let edit_count = rng.gen_range(1..=5);
1390                    buffer.randomly_mutate(&mut rng, edit_count, cx);
1391                    buffer_snapshot = buffer.snapshot(cx);
1392                    let edits = subscription.consume().into_inner();
1393                    log::info!("editing {:?}", edits);
1394                    buffer_edits.extend(edits);
1395                }),
1396            };
1397
1398            let (inlay_snapshot, new_inlay_edits) =
1399                inlay_map.sync(buffer_snapshot.clone(), buffer_edits);
1400            log::info!("inlay text {:?}", inlay_snapshot.text());
1401
1402            let inlay_edits = Patch::new(inlay_edits)
1403                .compose(new_inlay_edits)
1404                .into_inner();
1405            let (snapshot, edits) = map.read(inlay_snapshot.clone(), inlay_edits);
1406            snapshot_edits.push((snapshot.clone(), edits));
1407
1408            let mut expected_text: String = inlay_snapshot.text().to_string();
1409            for fold_range in map.merged_fold_ranges().into_iter().rev() {
1410                let fold_inlay_start = inlay_snapshot.to_inlay_offset(fold_range.start);
1411                let fold_inlay_end = inlay_snapshot.to_inlay_offset(fold_range.end);
1412                expected_text.replace_range(fold_inlay_start.0..fold_inlay_end.0, "");
1413            }
1414
1415            assert_eq!(snapshot.text(), expected_text);
1416            log::info!(
1417                "fold text {:?} ({} lines)",
1418                expected_text,
1419                expected_text.matches('\n').count() + 1
1420            );
1421
1422            let mut prev_row = 0;
1423            let mut expected_buffer_rows = Vec::new();
1424            for fold_range in map.merged_fold_ranges().into_iter() {
1425                let fold_start = inlay_snapshot
1426                    .to_point(inlay_snapshot.to_inlay_offset(fold_range.start))
1427                    .row();
1428                let fold_end = inlay_snapshot
1429                    .to_point(inlay_snapshot.to_inlay_offset(fold_range.end))
1430                    .row();
1431                expected_buffer_rows.extend(
1432                    inlay_snapshot
1433                        .buffer_rows(prev_row)
1434                        .take((1 + fold_start - prev_row) as usize),
1435                );
1436                prev_row = 1 + fold_end;
1437            }
1438            expected_buffer_rows.extend(inlay_snapshot.buffer_rows(prev_row));
1439
1440            assert_eq!(
1441                expected_buffer_rows.len(),
1442                expected_text.matches('\n').count() + 1,
1443                "wrong expected buffer rows {:?}. text: {:?}",
1444                expected_buffer_rows,
1445                expected_text
1446            );
1447
1448            for (output_row, line) in expected_text.lines().enumerate() {
1449                let line_len = snapshot.line_len(output_row as u32);
1450                assert_eq!(line_len, line.len() as u32);
1451            }
1452
1453            let longest_row = snapshot.longest_row();
1454            let longest_char_column = expected_text
1455                .split('\n')
1456                .nth(longest_row as usize)
1457                .unwrap()
1458                .chars()
1459                .count();
1460            let mut fold_point = FoldPoint::new(0, 0);
1461            let mut fold_offset = FoldOffset(0);
1462            let mut char_column = 0;
1463            for c in expected_text.chars() {
1464                let inlay_point = fold_point.to_inlay_point(&snapshot);
1465                let inlay_offset = fold_offset.to_inlay_offset(&snapshot);
1466                assert_eq!(
1467                    snapshot.to_fold_point(inlay_point, Right),
1468                    fold_point,
1469                    "{:?} -> fold point",
1470                    inlay_point,
1471                );
1472                assert_eq!(
1473                    inlay_snapshot.to_offset(inlay_point),
1474                    inlay_offset,
1475                    "inlay_snapshot.to_offset({:?})",
1476                    inlay_point,
1477                );
1478                assert_eq!(
1479                    fold_point.to_offset(&snapshot),
1480                    fold_offset,
1481                    "fold_point.to_offset({:?})",
1482                    fold_point,
1483                );
1484
1485                if c == '\n' {
1486                    *fold_point.row_mut() += 1;
1487                    *fold_point.column_mut() = 0;
1488                    char_column = 0;
1489                } else {
1490                    *fold_point.column_mut() += c.len_utf8() as u32;
1491                    char_column += 1;
1492                }
1493                fold_offset.0 += c.len_utf8();
1494                if char_column > longest_char_column {
1495                    panic!(
1496                        "invalid longest row {:?} (chars {}), found row {:?} (chars: {})",
1497                        longest_row,
1498                        longest_char_column,
1499                        fold_point.row(),
1500                        char_column
1501                    );
1502                }
1503            }
1504
1505            for _ in 0..5 {
1506                let mut start = snapshot
1507                    .clip_offset(FoldOffset(rng.gen_range(0..=snapshot.len().0)), Bias::Left);
1508                let mut end = snapshot
1509                    .clip_offset(FoldOffset(rng.gen_range(0..=snapshot.len().0)), Bias::Right);
1510                if start > end {
1511                    mem::swap(&mut start, &mut end);
1512                }
1513
1514                let text = &expected_text[start.0..end.0];
1515                assert_eq!(
1516                    snapshot
1517                        .chunks(start..end, false, Some(&highlights), None)
1518                        .map(|c| c.text)
1519                        .collect::<String>(),
1520                    text,
1521                );
1522            }
1523
1524            let mut fold_row = 0;
1525            while fold_row < expected_buffer_rows.len() as u32 {
1526                assert_eq!(
1527                    snapshot.buffer_rows(fold_row).collect::<Vec<_>>(),
1528                    expected_buffer_rows[(fold_row as usize)..],
1529                    "wrong buffer rows starting at fold row {}",
1530                    fold_row,
1531                );
1532                fold_row += 1;
1533            }
1534
1535            let folded_buffer_rows = map
1536                .merged_fold_ranges()
1537                .iter()
1538                .flat_map(|range| {
1539                    let start_row = range.start.to_point(&buffer_snapshot).row;
1540                    let end = range.end.to_point(&buffer_snapshot);
1541                    if end.column == 0 {
1542                        start_row..end.row
1543                    } else {
1544                        start_row..end.row + 1
1545                    }
1546                })
1547                .collect::<HashSet<_>>();
1548            for row in 0..=buffer_snapshot.max_point().row {
1549                assert_eq!(
1550                    snapshot.is_line_folded(row),
1551                    folded_buffer_rows.contains(&row),
1552                    "expected buffer row {}{} to be folded",
1553                    row,
1554                    if folded_buffer_rows.contains(&row) {
1555                        ""
1556                    } else {
1557                        " not"
1558                    }
1559                );
1560            }
1561
1562            for _ in 0..5 {
1563                let end =
1564                    buffer_snapshot.clip_offset(rng.gen_range(0..=buffer_snapshot.len()), Right);
1565                let start = buffer_snapshot.clip_offset(rng.gen_range(0..=end), Left);
1566                let expected_folds = map
1567                    .snapshot
1568                    .folds
1569                    .items(&buffer_snapshot)
1570                    .into_iter()
1571                    .filter(|fold| {
1572                        let start = buffer_snapshot.anchor_before(start);
1573                        let end = buffer_snapshot.anchor_after(end);
1574                        start.cmp(&fold.0.end, &buffer_snapshot) == Ordering::Less
1575                            && end.cmp(&fold.0.start, &buffer_snapshot) == Ordering::Greater
1576                    })
1577                    .map(|fold| fold.0)
1578                    .collect::<Vec<_>>();
1579
1580                assert_eq!(
1581                    snapshot
1582                        .folds_in_range(start..end)
1583                        .cloned()
1584                        .collect::<Vec<_>>(),
1585                    expected_folds
1586                );
1587            }
1588
1589            let text = snapshot.text();
1590            for _ in 0..5 {
1591                let start_row = rng.gen_range(0..=snapshot.max_point().row());
1592                let start_column = rng.gen_range(0..=snapshot.line_len(start_row));
1593                let end_row = rng.gen_range(0..=snapshot.max_point().row());
1594                let end_column = rng.gen_range(0..=snapshot.line_len(end_row));
1595                let mut start =
1596                    snapshot.clip_point(FoldPoint::new(start_row, start_column), Bias::Left);
1597                let mut end = snapshot.clip_point(FoldPoint::new(end_row, end_column), Bias::Right);
1598                if start > end {
1599                    mem::swap(&mut start, &mut end);
1600                }
1601
1602                let lines = start..end;
1603                let bytes = start.to_offset(&snapshot)..end.to_offset(&snapshot);
1604                assert_eq!(
1605                    snapshot.text_summary_for_range(lines),
1606                    TextSummary::from(&text[bytes.start.0..bytes.end.0])
1607                )
1608            }
1609
1610            let mut text = initial_snapshot.text();
1611            for (snapshot, edits) in snapshot_edits.drain(..) {
1612                let new_text = snapshot.text();
1613                for edit in edits {
1614                    let old_bytes = edit.new.start.0..edit.new.start.0 + edit.old_len().0;
1615                    let new_bytes = edit.new.start.0..edit.new.end.0;
1616                    text.replace_range(old_bytes, &new_text[new_bytes]);
1617                }
1618
1619                assert_eq!(text, new_text);
1620                initial_snapshot = snapshot;
1621            }
1622        }
1623    }
1624
1625    #[gpui::test]
1626    fn test_buffer_rows(cx: &mut gpui::AppContext) {
1627        let text = sample_text(6, 6, 'a') + "\n";
1628        let buffer = MultiBuffer::build_simple(&text, cx);
1629
1630        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1631        let (_, inlay_snapshot) = InlayMap::new(buffer_snapshot);
1632        let mut map = FoldMap::new(inlay_snapshot.clone()).0;
1633
1634        let (mut writer, _, _) = map.write(inlay_snapshot.clone(), vec![]);
1635        writer.fold(vec![
1636            Point::new(0, 2)..Point::new(2, 2),
1637            Point::new(3, 1)..Point::new(4, 1),
1638        ]);
1639
1640        let (snapshot, _) = map.read(inlay_snapshot, vec![]);
1641        assert_eq!(snapshot.text(), "aa⋯cccc\nd⋯eeeee\nffffff\n");
1642        assert_eq!(
1643            snapshot.buffer_rows(0).collect::<Vec<_>>(),
1644            [Some(0), Some(3), Some(5), Some(6)]
1645        );
1646        assert_eq!(snapshot.buffer_rows(3).collect::<Vec<_>>(), [Some(6)]);
1647    }
1648
1649    fn init_test(cx: &mut gpui::AppContext) {
1650        cx.set_global(SettingsStore::test(cx));
1651    }
1652
1653    impl FoldMap {
1654        fn merged_fold_ranges(&self) -> Vec<Range<usize>> {
1655            let inlay_snapshot = self.snapshot.inlay_snapshot.clone();
1656            let buffer = &inlay_snapshot.buffer;
1657            let mut folds = self.snapshot.folds.items(buffer);
1658            // Ensure sorting doesn't change how folds get merged and displayed.
1659            folds.sort_by(|a, b| a.0.cmp(&b.0, buffer));
1660            let mut fold_ranges = folds
1661                .iter()
1662                .map(|fold| fold.0.start.to_offset(buffer)..fold.0.end.to_offset(buffer))
1663                .peekable();
1664
1665            let mut merged_ranges = Vec::new();
1666            while let Some(mut fold_range) = fold_ranges.next() {
1667                while let Some(next_range) = fold_ranges.peek() {
1668                    if fold_range.end >= next_range.start {
1669                        if next_range.end > fold_range.end {
1670                            fold_range.end = next_range.end;
1671                        }
1672                        fold_ranges.next();
1673                    } else {
1674                        break;
1675                    }
1676                }
1677                if fold_range.end > fold_range.start {
1678                    merged_ranges.push(fold_range);
1679                }
1680            }
1681            merged_ranges
1682        }
1683
1684        pub fn randomly_mutate(
1685            &mut self,
1686            rng: &mut impl Rng,
1687        ) -> Vec<(FoldSnapshot, Vec<FoldEdit>)> {
1688            let mut snapshot_edits = Vec::new();
1689            match rng.gen_range(0..=100) {
1690                0..=39 if !self.snapshot.folds.is_empty() => {
1691                    let inlay_snapshot = self.snapshot.inlay_snapshot.clone();
1692                    let buffer = &inlay_snapshot.buffer;
1693                    let mut to_unfold = Vec::new();
1694                    for _ in 0..rng.gen_range(1..=3) {
1695                        let end = buffer.clip_offset(rng.gen_range(0..=buffer.len()), Right);
1696                        let start = buffer.clip_offset(rng.gen_range(0..=end), Left);
1697                        to_unfold.push(start..end);
1698                    }
1699                    log::info!("unfolding {:?}", to_unfold);
1700                    let (mut writer, snapshot, edits) = self.write(inlay_snapshot, vec![]);
1701                    snapshot_edits.push((snapshot, edits));
1702                    let (snapshot, edits) = writer.fold(to_unfold);
1703                    snapshot_edits.push((snapshot, edits));
1704                }
1705                _ => {
1706                    let inlay_snapshot = self.snapshot.inlay_snapshot.clone();
1707                    let buffer = &inlay_snapshot.buffer;
1708                    let mut to_fold = Vec::new();
1709                    for _ in 0..rng.gen_range(1..=2) {
1710                        let end = buffer.clip_offset(rng.gen_range(0..=buffer.len()), Right);
1711                        let start = buffer.clip_offset(rng.gen_range(0..=end), Left);
1712                        to_fold.push(start..end);
1713                    }
1714                    log::info!("folding {:?}", to_fold);
1715                    let (mut writer, snapshot, edits) = self.write(inlay_snapshot, vec![]);
1716                    snapshot_edits.push((snapshot, edits));
1717                    let (snapshot, edits) = writer.fold(to_fold);
1718                    snapshot_edits.push((snapshot, edits));
1719                }
1720            }
1721            snapshot_edits
1722        }
1723    }
1724}