wrap_map.rs

   1use super::{
   2    fold_map,
   3    patch::Patch,
   4    tab_map::{self, Edit as TabEdit, Snapshot as TabSnapshot, TabPoint},
   5};
   6use gpui::{
   7    fonts::FontId, text_layout::LineWrapper, Entity, ModelContext, ModelHandle, MutableAppContext,
   8    Task,
   9};
  10use language::{Chunk, Point};
  11use lazy_static::lazy_static;
  12use smol::future::yield_now;
  13use std::{collections::VecDeque, mem, ops::Range, time::Duration};
  14use sum_tree::{Bias, Cursor, SumTree};
  15
  16pub use super::tab_map::TextSummary;
  17pub type Edit = buffer::Edit<u32>;
  18
  19pub struct WrapMap {
  20    snapshot: Snapshot,
  21    pending_edits: VecDeque<(TabSnapshot, Vec<TabEdit>)>,
  22    interpolated_edits: Patch,
  23    edits_since_sync: Patch,
  24    wrap_width: Option<f32>,
  25    background_task: Option<Task<()>>,
  26    font: (FontId, f32),
  27}
  28
  29impl Entity for WrapMap {
  30    type Event = ();
  31}
  32
  33#[derive(Clone)]
  34pub struct Snapshot {
  35    tab_snapshot: TabSnapshot,
  36    transforms: SumTree<Transform>,
  37    interpolated: bool,
  38}
  39
  40#[derive(Clone, Debug, Default, Eq, PartialEq)]
  41struct Transform {
  42    summary: TransformSummary,
  43    display_text: Option<&'static str>,
  44}
  45
  46#[derive(Clone, Debug, Default, Eq, PartialEq)]
  47struct TransformSummary {
  48    input: TextSummary,
  49    output: TextSummary,
  50}
  51
  52#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  53pub struct WrapPoint(pub super::Point);
  54
  55pub struct Chunks<'a> {
  56    input_chunks: tab_map::Chunks<'a>,
  57    input_chunk: Chunk<'a>,
  58    output_position: WrapPoint,
  59    max_output_row: u32,
  60    transforms: Cursor<'a, Transform, (WrapPoint, TabPoint)>,
  61}
  62
  63pub struct BufferRows<'a> {
  64    input_buffer_rows: fold_map::BufferRows<'a>,
  65    input_buffer_row: u32,
  66    output_row: u32,
  67    soft_wrapped: bool,
  68    max_output_row: u32,
  69    transforms: Cursor<'a, Transform, (WrapPoint, TabPoint)>,
  70}
  71
  72impl WrapMap {
  73    pub fn new(
  74        tab_snapshot: TabSnapshot,
  75        font_id: FontId,
  76        font_size: f32,
  77        wrap_width: Option<f32>,
  78        cx: &mut MutableAppContext,
  79    ) -> (ModelHandle<Self>, Snapshot) {
  80        let handle = cx.add_model(|cx| {
  81            let mut this = Self {
  82                font: (font_id, font_size),
  83                wrap_width: None,
  84                pending_edits: Default::default(),
  85                interpolated_edits: Default::default(),
  86                edits_since_sync: Default::default(),
  87                snapshot: Snapshot::new(tab_snapshot),
  88                background_task: None,
  89            };
  90            this.set_wrap_width(wrap_width, cx);
  91            mem::take(&mut this.edits_since_sync);
  92            this
  93        });
  94        let snapshot = handle.read(cx).snapshot.clone();
  95        (handle, snapshot)
  96    }
  97
  98    #[cfg(test)]
  99    pub fn is_rewrapping(&self) -> bool {
 100        self.background_task.is_some()
 101    }
 102
 103    pub fn sync(
 104        &mut self,
 105        tab_snapshot: TabSnapshot,
 106        edits: Vec<TabEdit>,
 107        cx: &mut ModelContext<Self>,
 108    ) -> (Snapshot, Vec<Edit>) {
 109        self.pending_edits.push_back((tab_snapshot, edits));
 110        self.flush_edits(cx);
 111        (
 112            self.snapshot.clone(),
 113            mem::take(&mut self.edits_since_sync).into_inner(),
 114        )
 115    }
 116
 117    pub fn set_font(&mut self, font_id: FontId, font_size: f32, cx: &mut ModelContext<Self>) {
 118        if (font_id, font_size) != self.font {
 119            self.font = (font_id, font_size);
 120            self.rewrap(cx)
 121        }
 122    }
 123
 124    pub fn set_wrap_width(&mut self, wrap_width: Option<f32>, cx: &mut ModelContext<Self>) -> bool {
 125        if wrap_width == self.wrap_width {
 126            return false;
 127        }
 128
 129        self.wrap_width = wrap_width;
 130        self.rewrap(cx);
 131        true
 132    }
 133
 134    fn rewrap(&mut self, cx: &mut ModelContext<Self>) {
 135        self.background_task.take();
 136        self.interpolated_edits.clear();
 137        self.pending_edits.clear();
 138
 139        if let Some(wrap_width) = self.wrap_width {
 140            let mut new_snapshot = self.snapshot.clone();
 141            let font_cache = cx.font_cache().clone();
 142            let (font_id, font_size) = self.font;
 143            let task = cx.background().spawn(async move {
 144                let mut line_wrapper = font_cache.line_wrapper(font_id, font_size);
 145                let tab_snapshot = new_snapshot.tab_snapshot.clone();
 146                let range = TabPoint::zero()..tab_snapshot.max_point();
 147                let edits = new_snapshot
 148                    .update(
 149                        tab_snapshot,
 150                        &[TabEdit {
 151                            old_lines: range.clone(),
 152                            new_lines: range.clone(),
 153                        }],
 154                        wrap_width,
 155                        &mut line_wrapper,
 156                    )
 157                    .await;
 158                (new_snapshot, edits)
 159            });
 160
 161            match cx
 162                .background()
 163                .block_with_timeout(Duration::from_millis(5), task)
 164            {
 165                Ok((snapshot, edits)) => {
 166                    self.snapshot = snapshot;
 167                    self.edits_since_sync = self.edits_since_sync.compose(&edits);
 168                    cx.notify();
 169                }
 170                Err(wrap_task) => {
 171                    self.background_task = Some(cx.spawn(|this, mut cx| async move {
 172                        let (snapshot, edits) = wrap_task.await;
 173                        this.update(&mut cx, |this, cx| {
 174                            this.snapshot = snapshot;
 175                            this.edits_since_sync = this
 176                                .edits_since_sync
 177                                .compose(mem::take(&mut this.interpolated_edits).invert())
 178                                .compose(&edits);
 179                            this.background_task = None;
 180                            this.flush_edits(cx);
 181                            cx.notify();
 182                        });
 183                    }));
 184                }
 185            }
 186        } else {
 187            let old_rows = self.snapshot.transforms.summary().output.lines.row + 1;
 188            self.snapshot.transforms = SumTree::new();
 189            let summary = self.snapshot.tab_snapshot.text_summary();
 190            if !summary.lines.is_zero() {
 191                self.snapshot
 192                    .transforms
 193                    .push(Transform::isomorphic(summary), &());
 194            }
 195            let new_rows = self.snapshot.transforms.summary().output.lines.row + 1;
 196            self.snapshot.interpolated = false;
 197            self.edits_since_sync = self.edits_since_sync.compose(&unsafe {
 198                Patch::new_unchecked(vec![Edit {
 199                    old: 0..old_rows,
 200                    new: 0..new_rows,
 201                }])
 202            });
 203        }
 204    }
 205
 206    fn flush_edits(&mut self, cx: &mut ModelContext<Self>) {
 207        if !self.snapshot.interpolated {
 208            let mut to_remove_len = 0;
 209            for (tab_snapshot, _) in &self.pending_edits {
 210                if tab_snapshot.version() <= self.snapshot.tab_snapshot.version() {
 211                    to_remove_len += 1;
 212                } else {
 213                    break;
 214                }
 215            }
 216            self.pending_edits.drain(..to_remove_len);
 217        }
 218
 219        if self.pending_edits.is_empty() {
 220            return;
 221        }
 222
 223        if let Some(wrap_width) = self.wrap_width {
 224            if self.background_task.is_none() {
 225                let pending_edits = self.pending_edits.clone();
 226                let mut snapshot = self.snapshot.clone();
 227                let font_cache = cx.font_cache().clone();
 228                let (font_id, font_size) = self.font;
 229                let update_task = cx.background().spawn(async move {
 230                    let mut line_wrapper = font_cache.line_wrapper(font_id, font_size);
 231
 232                    let mut edits = Patch::default();
 233                    for (tab_snapshot, tab_edits) in pending_edits {
 234                        let wrap_edits = snapshot
 235                            .update(tab_snapshot, &tab_edits, wrap_width, &mut line_wrapper)
 236                            .await;
 237                        edits = edits.compose(&wrap_edits);
 238                    }
 239                    (snapshot, edits)
 240                });
 241
 242                match cx
 243                    .background()
 244                    .block_with_timeout(Duration::from_millis(1), update_task)
 245                {
 246                    Ok((snapshot, output_edits)) => {
 247                        self.snapshot = snapshot;
 248                        self.edits_since_sync = self.edits_since_sync.compose(&output_edits);
 249                    }
 250                    Err(update_task) => {
 251                        self.background_task = Some(cx.spawn(|this, mut cx| async move {
 252                            let (snapshot, edits) = update_task.await;
 253                            this.update(&mut cx, |this, cx| {
 254                                this.snapshot = snapshot;
 255                                this.edits_since_sync = this
 256                                    .edits_since_sync
 257                                    .compose(mem::take(&mut this.interpolated_edits).invert())
 258                                    .compose(&edits);
 259                                this.background_task = None;
 260                                this.flush_edits(cx);
 261                                cx.notify();
 262                            });
 263                        }));
 264                    }
 265                }
 266            }
 267        }
 268
 269        let was_interpolated = self.snapshot.interpolated;
 270        let mut to_remove_len = 0;
 271        for (tab_snapshot, edits) in &self.pending_edits {
 272            if tab_snapshot.version() <= self.snapshot.tab_snapshot.version() {
 273                to_remove_len += 1;
 274            } else {
 275                let interpolated_edits = self.snapshot.interpolate(tab_snapshot.clone(), &edits);
 276                self.edits_since_sync = self.edits_since_sync.compose(&interpolated_edits);
 277                self.interpolated_edits = self.interpolated_edits.compose(&interpolated_edits);
 278            }
 279        }
 280
 281        if !was_interpolated {
 282            self.pending_edits.drain(..to_remove_len);
 283        }
 284    }
 285}
 286
 287impl Snapshot {
 288    fn new(tab_snapshot: TabSnapshot) -> Self {
 289        let mut transforms = SumTree::new();
 290        let extent = tab_snapshot.text_summary();
 291        if !extent.lines.is_zero() {
 292            transforms.push(Transform::isomorphic(extent), &());
 293        }
 294        Self {
 295            transforms,
 296            tab_snapshot,
 297            interpolated: true,
 298        }
 299    }
 300
 301    fn interpolate(&mut self, new_tab_snapshot: TabSnapshot, tab_edits: &[TabEdit]) -> Patch {
 302        log::info!("INTERPOLATING");
 303
 304        log::info!("updating transforms... old transforms are:");
 305        for transform in self.transforms.items(&()) {
 306            log::info!("  - i {:?}", transform.summary.input);
 307            log::info!("    o {:?}", transform.summary.output);
 308        }
 309
 310        let mut new_transforms;
 311        if tab_edits.is_empty() {
 312            new_transforms = self.transforms.clone();
 313        } else {
 314            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 315
 316            let mut tab_edits_iter = tab_edits.iter().peekable();
 317            new_transforms = old_cursor.slice(
 318                &tab_edits_iter.peek().unwrap().old_lines.start,
 319                Bias::Right,
 320                &(),
 321            );
 322
 323            log::info!("sliced, new_transforms are:");
 324            for transform in new_transforms.items(&()) {
 325                log::info!("  - i {:?}", transform.summary.input);
 326                log::info!("    o {:?}", transform.summary.output);
 327            }
 328
 329            while let Some(edit) = tab_edits_iter.next() {
 330                log::info!("processing edit {:?}", edit);
 331
 332                if edit.new_lines.start > TabPoint::from(new_transforms.summary().input.lines) {
 333                    let summary = new_tab_snapshot.text_summary_for_range(
 334                        TabPoint::from(new_transforms.summary().input.lines)..edit.new_lines.start,
 335                    );
 336                    log::info!("pushing prefix before edit: {:?}", summary);
 337                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 338                    log::info!("new transforms are now:");
 339                    for transform in new_transforms.items(&()) {
 340                        log::info!("  - i {:?}", transform.summary.input);
 341                        log::info!("    o {:?}", transform.summary.output);
 342                    }
 343                }
 344
 345                if !edit.new_lines.is_empty() {
 346                    new_transforms.push_or_extend(Transform::isomorphic(
 347                        new_tab_snapshot.text_summary_for_range(edit.new_lines.clone()),
 348                    ));
 349                }
 350
 351                log::info!("pushed summary within edit new range; new transforms now:");
 352                for transform in new_transforms.items(&()) {
 353                    log::info!("  - i {:?}", transform.summary.input);
 354                    log::info!("    o {:?}", transform.summary.output);
 355                }
 356
 357                old_cursor.seek_forward(&edit.old_lines.end, Bias::Right, &());
 358                if let Some(next_edit) = tab_edits_iter.peek() {
 359                    if next_edit.old_lines.start > old_cursor.end(&()) {
 360                        if old_cursor.end(&()) > edit.old_lines.end {
 361                            let summary = self
 362                                .tab_snapshot
 363                                .text_summary_for_range(edit.old_lines.end..old_cursor.end(&()));
 364                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 365                        }
 366
 367                        log::info!("pushed transform suffix after edit; new transforms now:");
 368                        for transform in new_transforms.items(&()) {
 369                            log::info!("  - i {:?}", transform.summary.input);
 370                            log::info!("    o {:?}", transform.summary.output);
 371                        }
 372
 373                        old_cursor.next(&());
 374                        new_transforms.push_tree(
 375                            old_cursor.slice(&next_edit.old_lines.start, Bias::Right, &()),
 376                            &(),
 377                        );
 378
 379                        log::info!("pushed tree suffix after edit; new transforms now:");
 380                        for transform in new_transforms.items(&()) {
 381                            log::info!("  - i {:?}", transform.summary.input);
 382                            log::info!("    o {:?}", transform.summary.output);
 383                        }
 384                    }
 385                } else {
 386                    log::info!("no more edits");
 387                    if old_cursor.end(&()) > edit.old_lines.end {
 388                        let summary = self
 389                            .tab_snapshot
 390                            .text_summary_for_range(edit.old_lines.end..old_cursor.end(&()));
 391                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 392
 393                        log::info!("pushed transform suffix after edit; new transforms now:");
 394                        for transform in new_transforms.items(&()) {
 395                            log::info!("  - i {:?}", transform.summary.input);
 396                            log::info!("    o {:?}", transform.summary.output);
 397                        }
 398                    }
 399                    old_cursor.next(&());
 400                    new_transforms.push_tree(old_cursor.suffix(&()), &());
 401                    log::info!("pushed suffix:");
 402                    for transform in new_transforms.items(&()) {
 403                        log::info!("  - i {:?}", transform.summary.input);
 404                        log::info!("    o {:?}", transform.summary.output);
 405                    }
 406                }
 407            }
 408        }
 409
 410        let old_snapshot = mem::replace(
 411            self,
 412            Snapshot {
 413                tab_snapshot: new_tab_snapshot,
 414                transforms: new_transforms,
 415                interpolated: true,
 416            },
 417        );
 418        self.check_invariants();
 419        old_snapshot.compute_edits(tab_edits, self)
 420    }
 421
 422    async fn update(
 423        &mut self,
 424        new_tab_snapshot: TabSnapshot,
 425        tab_edits: &[TabEdit],
 426        wrap_width: f32,
 427        line_wrapper: &mut LineWrapper,
 428    ) -> Patch {
 429        #[derive(Debug)]
 430        struct RowEdit {
 431            old_rows: Range<u32>,
 432            new_rows: Range<u32>,
 433        }
 434
 435        log::info!("updating transforms... old transforms are:");
 436        for transform in self.transforms.items(&()) {
 437            log::info!("  - i {:?}", transform.summary.input);
 438            log::info!("    o {:?}", transform.summary.output);
 439        }
 440
 441        let mut tab_edits_iter = tab_edits.into_iter().peekable();
 442        let mut row_edits = Vec::new();
 443        while let Some(edit) = tab_edits_iter.next() {
 444            let mut row_edit = RowEdit {
 445                old_rows: edit.old_lines.start.row()..edit.old_lines.end.row() + 1,
 446                new_rows: edit.new_lines.start.row()..edit.new_lines.end.row() + 1,
 447            };
 448
 449            while let Some(next_edit) = tab_edits_iter.peek() {
 450                if next_edit.old_lines.start.row() <= row_edit.old_rows.end {
 451                    row_edit.old_rows.end = next_edit.old_lines.end.row() + 1;
 452                    row_edit.new_rows.end = next_edit.new_lines.end.row() + 1;
 453                    tab_edits_iter.next();
 454                } else {
 455                    break;
 456                }
 457            }
 458
 459            row_edits.push(row_edit);
 460        }
 461
 462        log::info!("row edits are:");
 463        for edit in &row_edits {
 464            log::info!("  {:?}", edit);
 465        }
 466
 467        let mut new_transforms;
 468        if row_edits.is_empty() {
 469            new_transforms = self.transforms.clone();
 470        } else {
 471            let mut row_edits = row_edits.into_iter().peekable();
 472            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 473
 474            new_transforms = old_cursor.slice(
 475                &TabPoint::new(row_edits.peek().unwrap().old_rows.start, 0),
 476                Bias::Right,
 477                &(),
 478            );
 479
 480            log::info!("sliced a prefix:");
 481            for transform in new_transforms.items(&()) {
 482                log::info!("  - i {:?}", transform.summary.input);
 483                log::info!("    o {:?}", transform.summary.output);
 484            }
 485
 486            while let Some(edit) = row_edits.next() {
 487                if edit.new_rows.start > new_transforms.summary().input.lines.row {
 488                    let summary = new_tab_snapshot.text_summary_for_range(
 489                        TabPoint(new_transforms.summary().input.lines)
 490                            ..TabPoint::new(edit.new_rows.start, 0),
 491                    );
 492                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 493                }
 494
 495                let mut line = String::new();
 496                let mut remaining = None;
 497                let mut chunks = new_tab_snapshot.chunks(
 498                    TabPoint::new(edit.new_rows.start, 0)..new_tab_snapshot.max_point(),
 499                    false,
 500                );
 501                let mut edit_transforms = Vec::<Transform>::new();
 502                for _ in edit.new_rows.start..edit.new_rows.end {
 503                    while let Some(chunk) =
 504                        remaining.take().or_else(|| chunks.next().map(|c| c.text))
 505                    {
 506                        if let Some(ix) = chunk.find('\n') {
 507                            line.push_str(&chunk[..ix + 1]);
 508                            remaining = Some(&chunk[ix + 1..]);
 509                            break;
 510                        } else {
 511                            line.push_str(chunk)
 512                        }
 513                    }
 514
 515                    if line.is_empty() {
 516                        break;
 517                    }
 518
 519                    let mut prev_boundary_ix = 0;
 520                    for boundary in line_wrapper.wrap_line(&line, wrap_width) {
 521                        let wrapped = &line[prev_boundary_ix..boundary.ix];
 522                        push_isomorphic(&mut edit_transforms, TextSummary::from(wrapped));
 523                        edit_transforms.push(Transform::wrap(boundary.next_indent));
 524                        prev_boundary_ix = boundary.ix;
 525                    }
 526
 527                    if prev_boundary_ix < line.len() {
 528                        push_isomorphic(
 529                            &mut edit_transforms,
 530                            TextSummary::from(&line[prev_boundary_ix..]),
 531                        );
 532                    }
 533
 534                    line.clear();
 535                    yield_now().await;
 536                }
 537
 538                let mut edit_transforms = edit_transforms.into_iter();
 539                log::info!("extending tree with edit transforms");
 540                if let Some(transform) = edit_transforms.next() {
 541                    log::info!(
 542                        "push or extend with first transform: {:?}",
 543                        transform.summary.output
 544                    );
 545                    new_transforms.push_or_extend(transform);
 546                }
 547                log::info!("extending with remaining transforms");
 548                new_transforms.extend(edit_transforms, &());
 549
 550                old_cursor.seek_forward(&TabPoint::new(edit.old_rows.end, 0), Bias::Right, &());
 551                if let Some(next_edit) = row_edits.peek() {
 552                    if next_edit.old_rows.start > old_cursor.end(&()).row() {
 553                        if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 554                            let summary = self.tab_snapshot.text_summary_for_range(
 555                                TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 556                            );
 557                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 558                        }
 559                        old_cursor.next(&());
 560                        new_transforms.push_tree(
 561                            old_cursor.slice(
 562                                &TabPoint::new(next_edit.old_rows.start, 0),
 563                                Bias::Right,
 564                                &(),
 565                            ),
 566                            &(),
 567                        );
 568                    }
 569                } else {
 570                    if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 571                        let summary = self.tab_snapshot.text_summary_for_range(
 572                            TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 573                        );
 574                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 575                    }
 576                    old_cursor.next(&());
 577                    new_transforms.push_tree(old_cursor.suffix(&()), &());
 578                }
 579            }
 580        }
 581
 582        let old_snapshot = mem::replace(
 583            self,
 584            Snapshot {
 585                tab_snapshot: new_tab_snapshot,
 586                transforms: new_transforms,
 587                interpolated: false,
 588            },
 589        );
 590        self.check_invariants();
 591        old_snapshot.compute_edits(tab_edits, self)
 592    }
 593
 594    fn compute_edits(&self, tab_edits: &[TabEdit], new_snapshot: &Snapshot) -> Patch {
 595        let mut wrap_edits = Vec::new();
 596        let mut old_cursor = self.transforms.cursor::<TransformSummary>();
 597        let mut new_cursor = new_snapshot.transforms.cursor::<TransformSummary>();
 598        for mut tab_edit in tab_edits.iter().cloned() {
 599            tab_edit.old_lines.start.0.column = 0;
 600            tab_edit.old_lines.end.0 += Point::new(1, 0);
 601            tab_edit.new_lines.start.0.column = 0;
 602            tab_edit.new_lines.end.0 += Point::new(1, 0);
 603
 604            old_cursor.seek(&tab_edit.old_lines.start, Bias::Right, &());
 605            let mut old_start = old_cursor.start().output.lines;
 606            old_start += tab_edit.old_lines.start.0 - old_cursor.start().input.lines;
 607
 608            old_cursor.seek(&tab_edit.old_lines.end, Bias::Right, &());
 609            let mut old_end = old_cursor.start().output.lines;
 610            old_end += tab_edit.old_lines.end.0 - old_cursor.start().input.lines;
 611
 612            new_cursor.seek(&tab_edit.new_lines.start, Bias::Right, &());
 613            let mut new_start = new_cursor.start().output.lines;
 614            new_start += tab_edit.new_lines.start.0 - new_cursor.start().input.lines;
 615
 616            new_cursor.seek(&tab_edit.new_lines.end, Bias::Right, &());
 617            let mut new_end = new_cursor.start().output.lines;
 618            new_end += tab_edit.new_lines.end.0 - new_cursor.start().input.lines;
 619
 620            wrap_edits.push(Edit {
 621                old: old_start.row..old_end.row,
 622                new: new_start.row..new_end.row,
 623            });
 624        }
 625
 626        consolidate_wrap_edits(&mut wrap_edits);
 627        unsafe { Patch::new_unchecked(wrap_edits) }
 628    }
 629
 630    pub fn text_chunks(&self, wrap_row: u32) -> impl Iterator<Item = &str> {
 631        self.chunks(wrap_row..self.max_point().row() + 1, false)
 632            .map(|h| h.text)
 633    }
 634
 635    pub fn chunks(&self, rows: Range<u32>, highlights: bool) -> Chunks {
 636        let output_start = WrapPoint::new(rows.start, 0);
 637        let output_end = WrapPoint::new(rows.end, 0);
 638        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 639        transforms.seek(&output_start, Bias::Right, &());
 640        let mut input_start = TabPoint(transforms.start().1 .0);
 641        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 642            input_start.0 += output_start.0 - transforms.start().0 .0;
 643        }
 644        let input_end = self
 645            .to_tab_point(output_end)
 646            .min(self.tab_snapshot.max_point());
 647        Chunks {
 648            input_chunks: self.tab_snapshot.chunks(input_start..input_end, highlights),
 649            input_chunk: Default::default(),
 650            output_position: output_start,
 651            max_output_row: rows.end,
 652            transforms,
 653        }
 654    }
 655
 656    pub fn text_summary(&self) -> TextSummary {
 657        self.transforms.summary().output
 658    }
 659
 660    pub fn max_point(&self) -> WrapPoint {
 661        WrapPoint(self.transforms.summary().output.lines)
 662    }
 663
 664    pub fn line_len(&self, row: u32) -> u32 {
 665        let mut len = 0;
 666        for chunk in self.text_chunks(row) {
 667            if let Some(newline_ix) = chunk.find('\n') {
 668                len += newline_ix;
 669                break;
 670            } else {
 671                len += chunk.len();
 672            }
 673        }
 674        len as u32
 675    }
 676
 677    pub fn soft_wrap_indent(&self, row: u32) -> Option<u32> {
 678        let mut cursor = self.transforms.cursor::<WrapPoint>();
 679        cursor.seek(&WrapPoint::new(row + 1, 0), Bias::Right, &());
 680        cursor.item().and_then(|transform| {
 681            if transform.is_isomorphic() {
 682                None
 683            } else {
 684                Some(transform.summary.output.lines.column)
 685            }
 686        })
 687    }
 688
 689    pub fn longest_row(&self) -> u32 {
 690        self.transforms.summary().output.longest_row
 691    }
 692
 693    pub fn buffer_rows(&self, start_row: u32) -> BufferRows {
 694        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 695        transforms.seek(&WrapPoint::new(start_row, 0), Bias::Left, &());
 696        let mut input_row = transforms.start().1.row();
 697        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 698            input_row += start_row - transforms.start().0.row();
 699        }
 700        let soft_wrapped = transforms.item().map_or(false, |t| !t.is_isomorphic());
 701        let mut input_buffer_rows = self.tab_snapshot.buffer_rows(input_row);
 702        let input_buffer_row = input_buffer_rows.next().unwrap();
 703        BufferRows {
 704            transforms,
 705            input_buffer_row,
 706            input_buffer_rows,
 707            output_row: start_row,
 708            soft_wrapped,
 709            max_output_row: self.max_point().row(),
 710        }
 711    }
 712
 713    pub fn to_tab_point(&self, point: WrapPoint) -> TabPoint {
 714        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 715        cursor.seek(&point, Bias::Right, &());
 716        let mut tab_point = cursor.start().1 .0;
 717        if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 718            tab_point += point.0 - cursor.start().0 .0;
 719        }
 720        TabPoint(tab_point)
 721    }
 722
 723    pub fn to_point(&self, point: WrapPoint, bias: Bias) -> Point {
 724        self.tab_snapshot.to_point(self.to_tab_point(point), bias)
 725    }
 726
 727    pub fn from_point(&self, point: Point, bias: Bias) -> WrapPoint {
 728        self.from_tab_point(self.tab_snapshot.from_point(point, bias))
 729    }
 730
 731    pub fn from_tab_point(&self, point: TabPoint) -> WrapPoint {
 732        let mut cursor = self.transforms.cursor::<(TabPoint, WrapPoint)>();
 733        cursor.seek(&point, Bias::Right, &());
 734        WrapPoint(cursor.start().1 .0 + (point.0 - cursor.start().0 .0))
 735    }
 736
 737    pub fn clip_point(&self, mut point: WrapPoint, bias: Bias) -> WrapPoint {
 738        if bias == Bias::Left {
 739            let mut cursor = self.transforms.cursor::<WrapPoint>();
 740            cursor.seek(&point, Bias::Right, &());
 741            if cursor.item().map_or(false, |t| !t.is_isomorphic()) {
 742                point = *cursor.start();
 743                *point.column_mut() -= 1;
 744            }
 745        }
 746
 747        self.from_tab_point(self.tab_snapshot.clip_point(self.to_tab_point(point), bias))
 748    }
 749
 750    fn check_invariants(&self) {
 751        #[cfg(test)]
 752        {
 753            assert_eq!(
 754                TabPoint::from(self.transforms.summary().input.lines),
 755                self.tab_snapshot.max_point()
 756            );
 757
 758            {
 759                let mut transforms = self.transforms.cursor::<()>().peekable();
 760                while let Some(transform) = transforms.next() {
 761                    if let Some(next_transform) = transforms.peek() {
 762                        assert!(transform.is_isomorphic() != next_transform.is_isomorphic());
 763                    }
 764                }
 765            }
 766
 767            let mut expected_buffer_rows = Vec::new();
 768            let mut buffer_row = 0;
 769            let mut prev_tab_row = 0;
 770            for display_row in 0..=self.max_point().row() {
 771                let tab_point = self.to_tab_point(WrapPoint::new(display_row, 0));
 772                let soft_wrapped;
 773                if tab_point.row() == prev_tab_row {
 774                    soft_wrapped = display_row != 0;
 775                } else {
 776                    let fold_point = self.tab_snapshot.to_fold_point(tab_point, Bias::Left).0;
 777                    let buffer_point = fold_point.to_buffer_point(&self.tab_snapshot.fold_snapshot);
 778                    buffer_row = buffer_point.row;
 779                    prev_tab_row = tab_point.row();
 780                    soft_wrapped = false;
 781                }
 782                expected_buffer_rows.push(if soft_wrapped { None } else { Some(buffer_row) });
 783            }
 784
 785            for start_display_row in 0..expected_buffer_rows.len() {
 786                assert_eq!(
 787                    self.buffer_rows(start_display_row as u32)
 788                        .collect::<Vec<_>>(),
 789                    &expected_buffer_rows[start_display_row..],
 790                    "invalid buffer_rows({}..)",
 791                    start_display_row
 792                );
 793            }
 794        }
 795    }
 796}
 797
 798impl<'a> Iterator for Chunks<'a> {
 799    type Item = Chunk<'a>;
 800
 801    fn next(&mut self) -> Option<Self::Item> {
 802        if self.output_position.row() >= self.max_output_row {
 803            return None;
 804        }
 805
 806        let transform = self.transforms.item()?;
 807        if let Some(display_text) = transform.display_text {
 808            let mut start_ix = 0;
 809            let mut end_ix = display_text.len();
 810            let mut summary = transform.summary.output.lines;
 811
 812            if self.output_position > self.transforms.start().0 {
 813                // Exclude newline starting prior to the desired row.
 814                start_ix = 1;
 815                summary.row = 0;
 816            } else if self.output_position.row() + 1 >= self.max_output_row {
 817                // Exclude soft indentation ending after the desired row.
 818                end_ix = 1;
 819                summary.column = 0;
 820            }
 821
 822            self.output_position.0 += summary;
 823            self.transforms.next(&());
 824            return Some(Chunk {
 825                text: &display_text[start_ix..end_ix],
 826                ..self.input_chunk
 827            });
 828        }
 829
 830        if self.input_chunk.text.is_empty() {
 831            self.input_chunk = self.input_chunks.next().unwrap();
 832        }
 833
 834        let mut input_len = 0;
 835        let transform_end = self.transforms.end(&()).0;
 836        for c in self.input_chunk.text.chars() {
 837            let char_len = c.len_utf8();
 838            input_len += char_len;
 839            if c == '\n' {
 840                *self.output_position.row_mut() += 1;
 841                *self.output_position.column_mut() = 0;
 842            } else {
 843                *self.output_position.column_mut() += char_len as u32;
 844            }
 845
 846            if self.output_position >= transform_end {
 847                self.transforms.next(&());
 848                break;
 849            }
 850        }
 851
 852        let (prefix, suffix) = self.input_chunk.text.split_at(input_len);
 853        self.input_chunk.text = suffix;
 854        Some(Chunk {
 855            text: prefix,
 856            ..self.input_chunk
 857        })
 858    }
 859}
 860
 861impl<'a> Iterator for BufferRows<'a> {
 862    type Item = Option<u32>;
 863
 864    fn next(&mut self) -> Option<Self::Item> {
 865        if self.output_row > self.max_output_row {
 866            return None;
 867        }
 868
 869        let buffer_row = self.input_buffer_row;
 870        let soft_wrapped = self.soft_wrapped;
 871
 872        self.output_row += 1;
 873        self.transforms
 874            .seek_forward(&WrapPoint::new(self.output_row, 0), Bias::Left, &());
 875        if self.transforms.item().map_or(false, |t| t.is_isomorphic()) {
 876            self.input_buffer_row = self.input_buffer_rows.next().unwrap();
 877            self.soft_wrapped = false;
 878        } else {
 879            self.soft_wrapped = true;
 880        }
 881
 882        Some(if soft_wrapped { None } else { Some(buffer_row) })
 883    }
 884}
 885
 886impl Transform {
 887    fn isomorphic(summary: TextSummary) -> Self {
 888        #[cfg(test)]
 889        assert!(!summary.lines.is_zero());
 890
 891        Self {
 892            summary: TransformSummary {
 893                input: summary.clone(),
 894                output: summary,
 895            },
 896            display_text: None,
 897        }
 898    }
 899
 900    fn wrap(indent: u32) -> Self {
 901        lazy_static! {
 902            static ref WRAP_TEXT: String = {
 903                let mut wrap_text = String::new();
 904                wrap_text.push('\n');
 905                wrap_text.extend((0..LineWrapper::MAX_INDENT as usize).map(|_| ' '));
 906                wrap_text
 907            };
 908        }
 909
 910        Self {
 911            summary: TransformSummary {
 912                input: TextSummary::default(),
 913                output: TextSummary {
 914                    lines: Point::new(1, indent),
 915                    first_line_chars: 0,
 916                    last_line_chars: indent,
 917                    longest_row: 1,
 918                    longest_row_chars: indent,
 919                },
 920            },
 921            display_text: Some(&WRAP_TEXT[..1 + indent as usize]),
 922        }
 923    }
 924
 925    fn is_isomorphic(&self) -> bool {
 926        self.display_text.is_none()
 927    }
 928}
 929
 930impl sum_tree::Item for Transform {
 931    type Summary = TransformSummary;
 932
 933    fn summary(&self) -> Self::Summary {
 934        self.summary.clone()
 935    }
 936}
 937
 938fn push_isomorphic(transforms: &mut Vec<Transform>, summary: TextSummary) {
 939    log::info!("push_isomorphic: {:?}", summary);
 940    if let Some(last_transform) = transforms.last_mut() {
 941        if last_transform.is_isomorphic() {
 942            last_transform.summary.input += &summary;
 943            last_transform.summary.output += &summary;
 944
 945            log::info!(
 946                "  extended previous isomorphic: {:?}",
 947                last_transform.summary.output
 948            );
 949
 950            return;
 951        }
 952    }
 953    transforms.push(Transform::isomorphic(summary));
 954}
 955
 956trait SumTreeExt {
 957    fn push_or_extend(&mut self, transform: Transform);
 958}
 959
 960impl SumTreeExt for SumTree<Transform> {
 961    fn push_or_extend(&mut self, transform: Transform) {
 962        let mut transform = Some(transform);
 963        self.update_last(
 964            |last_transform| {
 965                if last_transform.is_isomorphic() && transform.as_ref().unwrap().is_isomorphic() {
 966                    // log::info!("extending last transform in tree");
 967                    // log::info!(
 968                    //     "  extending with: {:?}",
 969                    //     transform.as_ref().map(|t| t.summary.output.clone()),
 970                    // );
 971                    // log::info!("  last transform was: {:?}", last_transform.summary.output);
 972
 973                    let transform = transform.take().unwrap();
 974                    last_transform.summary.input += &transform.summary.input;
 975                    last_transform.summary.output += &transform.summary.output;
 976
 977                    // log::info!(
 978                    //     "  last transform is now {:?}",
 979                    //     last_transform.summary.output,
 980                    // )
 981                }
 982            },
 983            &(),
 984        );
 985
 986        if let Some(transform) = transform {
 987            log::info!("!!!!!!!!!!! push transform: {:?}", transform.summary.output,);
 988            self.push(transform, &());
 989        }
 990    }
 991}
 992
 993impl WrapPoint {
 994    pub fn new(row: u32, column: u32) -> Self {
 995        Self(super::Point::new(row, column))
 996    }
 997
 998    pub fn row(self) -> u32 {
 999        self.0.row
1000    }
1001
1002    pub fn row_mut(&mut self) -> &mut u32 {
1003        &mut self.0.row
1004    }
1005
1006    pub fn column_mut(&mut self) -> &mut u32 {
1007        &mut self.0.column
1008    }
1009}
1010
1011impl sum_tree::Summary for TransformSummary {
1012    type Context = ();
1013
1014    fn add_summary(&mut self, other: &Self, _: &()) {
1015        self.input += &other.input;
1016        self.output += &other.output;
1017    }
1018}
1019
1020impl<'a> sum_tree::Dimension<'a, TransformSummary> for TabPoint {
1021    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1022        self.0 += summary.input.lines;
1023    }
1024}
1025
1026impl<'a> sum_tree::SeekTarget<'a, TransformSummary, TransformSummary> for TabPoint {
1027    fn cmp(&self, cursor_location: &TransformSummary, _: &()) -> std::cmp::Ordering {
1028        Ord::cmp(&self.0, &cursor_location.input.lines)
1029    }
1030}
1031
1032impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapPoint {
1033    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1034        self.0 += summary.output.lines;
1035    }
1036}
1037
1038fn consolidate_wrap_edits(edits: &mut Vec<Edit>) {
1039    let mut i = 1;
1040    while i < edits.len() {
1041        let edit = edits[i].clone();
1042        let prev_edit = &mut edits[i - 1];
1043        if prev_edit.old.end >= edit.old.start {
1044            prev_edit.old.end = edit.old.end;
1045            prev_edit.new.end = edit.new.end;
1046            edits.remove(i);
1047            continue;
1048        }
1049        i += 1;
1050    }
1051}
1052
1053#[cfg(test)]
1054mod tests {
1055    use super::*;
1056    use crate::{
1057        display_map::{fold_map::FoldMap, tab_map::TabMap},
1058        test::Observer,
1059    };
1060    use buffer::Rope;
1061    use language::{Buffer, RandomCharIter};
1062    use rand::prelude::*;
1063    use std::{cmp, env};
1064
1065    #[gpui::test(iterations = 100)]
1066    async fn test_random_wraps(mut cx: gpui::TestAppContext, mut rng: StdRng) {
1067        cx.foreground().set_block_on_ticks(0..=50);
1068        cx.foreground().forbid_parking();
1069        let operations = env::var("OPERATIONS")
1070            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1071            .unwrap_or(10);
1072
1073        let font_cache = cx.font_cache().clone();
1074        let font_system = cx.platform().fonts();
1075        let mut wrap_width = if rng.gen_bool(0.1) {
1076            None
1077        } else {
1078            Some(rng.gen_range(0.0..=1000.0))
1079        };
1080        let tab_size = rng.gen_range(1..=4);
1081        let family_id = font_cache.load_family(&["Helvetica"]).unwrap();
1082        let font_id = font_cache
1083            .select_font(family_id, &Default::default())
1084            .unwrap();
1085        let font_size = 14.0;
1086
1087        log::info!("Tab size: {}", tab_size);
1088        log::info!("Wrap width: {:?}", wrap_width);
1089
1090        let buffer = cx.add_model(|cx| {
1091            let len = rng.gen_range(0..10);
1092            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1093            Buffer::new(0, text, cx)
1094        });
1095        let (mut fold_map, folds_snapshot) = cx.read(|cx| FoldMap::new(buffer.clone(), cx));
1096        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), tab_size);
1097        log::info!(
1098            "Unwrapped text (no folds): {:?}",
1099            buffer.read_with(&cx, |buf, _| buf.text())
1100        );
1101        log::info!(
1102            "Unwrapped text (unexpanded tabs): {:?}",
1103            folds_snapshot.text()
1104        );
1105        log::info!("Unwrapped text (expanded tabs): {:?}", tabs_snapshot.text());
1106
1107        let mut line_wrapper = LineWrapper::new(font_id, font_size, font_system);
1108        let unwrapped_text = tabs_snapshot.text();
1109        let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1110
1111        let (wrap_map, _) =
1112            cx.update(|cx| WrapMap::new(tabs_snapshot.clone(), font_id, font_size, wrap_width, cx));
1113        let (_observer, notifications) = Observer::new(&wrap_map, &mut cx);
1114
1115        if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1116            notifications.recv().await.unwrap();
1117        }
1118
1119        let (initial_snapshot, _) = wrap_map.update(&mut cx, |map, cx| {
1120            assert!(!map.is_rewrapping());
1121            map.sync(tabs_snapshot.clone(), Vec::new(), cx)
1122        });
1123
1124        let actual_text = initial_snapshot.text();
1125        assert_eq!(
1126            actual_text, expected_text,
1127            "unwrapped text is: {:?}",
1128            unwrapped_text
1129        );
1130        log::info!("Wrapped text: {:?}", actual_text);
1131
1132        let mut edits = Vec::new();
1133        for _i in 0..operations {
1134            log::info!("{} ==============================================", _i);
1135
1136            match rng.gen_range(0..=100) {
1137                0..=19 => {
1138                    wrap_width = if rng.gen_bool(0.2) {
1139                        None
1140                    } else {
1141                        Some(rng.gen_range(0.0..=1000.0))
1142                    };
1143                    log::info!("Setting wrap width to {:?}", wrap_width);
1144                    wrap_map.update(&mut cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1145                }
1146                20..=39 => {
1147                    for (folds_snapshot, fold_edits) in
1148                        cx.read(|cx| fold_map.randomly_mutate(&mut rng, cx))
1149                    {
1150                        let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1151                        let (mut snapshot, wrap_edits) = wrap_map
1152                            .update(&mut cx, |map, cx| map.sync(tabs_snapshot, tab_edits, cx));
1153                        snapshot.check_invariants();
1154                        snapshot.verify_chunks(&mut rng);
1155                        edits.push((snapshot, wrap_edits));
1156                    }
1157                }
1158                _ => {
1159                    buffer.update(&mut cx, |buffer, _| buffer.randomly_mutate(&mut rng));
1160                }
1161            }
1162
1163            log::info!(
1164                "Unwrapped text (no folds): {:?}",
1165                buffer.read_with(&cx, |buf, _| buf.text())
1166            );
1167            let (folds_snapshot, fold_edits) = cx.read(|cx| fold_map.read(cx));
1168            log::info!(
1169                "Unwrapped text (unexpanded tabs): {:?}",
1170                folds_snapshot.text()
1171            );
1172            let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1173            log::info!("Unwrapped text (expanded tabs): {:?}", tabs_snapshot.text());
1174
1175            let unwrapped_text = tabs_snapshot.text();
1176            let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1177            let (mut snapshot, wrap_edits) = wrap_map.update(&mut cx, |map, cx| {
1178                map.sync(tabs_snapshot.clone(), tab_edits, cx)
1179            });
1180            snapshot.check_invariants();
1181            snapshot.verify_chunks(&mut rng);
1182            edits.push((snapshot, wrap_edits));
1183
1184            if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) && rng.gen_bool(0.4) {
1185                log::info!("Waiting for wrapping to finish");
1186                while wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1187                    notifications.recv().await.unwrap();
1188                }
1189            }
1190
1191            if !wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1192                let (mut wrapped_snapshot, wrap_edits) =
1193                    wrap_map.update(&mut cx, |map, cx| map.sync(tabs_snapshot, Vec::new(), cx));
1194                let actual_text = wrapped_snapshot.text();
1195                let actual_longest_row = wrapped_snapshot.longest_row();
1196                log::info!("Wrapping finished: {:?}", actual_text);
1197                wrapped_snapshot.check_invariants();
1198                wrapped_snapshot.verify_chunks(&mut rng);
1199                edits.push((wrapped_snapshot.clone(), wrap_edits));
1200                assert_eq!(
1201                    actual_text, expected_text,
1202                    "unwrapped text is: {:?}",
1203                    unwrapped_text
1204                );
1205
1206                let mut summary = TextSummary::default();
1207                for (ix, item) in wrapped_snapshot
1208                    .transforms
1209                    .items(&())
1210                    .into_iter()
1211                    .enumerate()
1212                {
1213                    summary += &item.summary.output;
1214                    log::info!("{} summary: {:?}", ix, item.summary.output,);
1215                }
1216
1217                if tab_size == 1
1218                    || !wrapped_snapshot
1219                        .tab_snapshot
1220                        .fold_snapshot
1221                        .text()
1222                        .contains('\t')
1223                {
1224                    let mut expected_longest_rows = Vec::new();
1225                    let mut longest_line_len = -1;
1226                    for (row, line) in expected_text.split('\n').enumerate() {
1227                        let line_char_count = line.chars().count() as isize;
1228                        if line_char_count > longest_line_len {
1229                            expected_longest_rows.clear();
1230                            longest_line_len = line_char_count;
1231                        }
1232                        if line_char_count >= longest_line_len {
1233                            expected_longest_rows.push(row as u32);
1234                        }
1235                    }
1236
1237                    assert!(
1238                        expected_longest_rows.contains(&actual_longest_row),
1239                        "incorrect longest row {}. expected {:?} with length {}",
1240                        actual_longest_row,
1241                        expected_longest_rows,
1242                        longest_line_len,
1243                    )
1244                }
1245            }
1246        }
1247
1248        let mut initial_text = Rope::from(initial_snapshot.text().as_str());
1249        for (snapshot, patch) in edits {
1250            let snapshot_text = Rope::from(snapshot.text().as_str());
1251            for edit in &patch {
1252                let old_start = initial_text.point_to_offset(Point::new(edit.new.start, 0));
1253                let old_end = initial_text.point_to_offset(cmp::min(
1254                    Point::new(edit.new.start + edit.old.len() as u32, 0),
1255                    initial_text.max_point(),
1256                ));
1257                let new_start = snapshot_text.point_to_offset(Point::new(edit.new.start, 0));
1258                let new_end = snapshot_text.point_to_offset(cmp::min(
1259                    Point::new(edit.new.end, 0),
1260                    snapshot_text.max_point(),
1261                ));
1262                let new_text = snapshot_text
1263                    .chunks_in_range(new_start..new_end)
1264                    .collect::<String>();
1265
1266                initial_text.replace(old_start..old_end, &new_text);
1267            }
1268            assert_eq!(initial_text.to_string(), snapshot_text.to_string());
1269        }
1270    }
1271
1272    fn wrap_text(
1273        unwrapped_text: &str,
1274        wrap_width: Option<f32>,
1275        line_wrapper: &mut LineWrapper,
1276    ) -> String {
1277        if let Some(wrap_width) = wrap_width {
1278            let mut wrapped_text = String::new();
1279            for (row, line) in unwrapped_text.split('\n').enumerate() {
1280                if row > 0 {
1281                    wrapped_text.push('\n')
1282                }
1283
1284                let mut prev_ix = 0;
1285                for boundary in line_wrapper.wrap_line(line, wrap_width) {
1286                    wrapped_text.push_str(&line[prev_ix..boundary.ix]);
1287                    wrapped_text.push('\n');
1288                    wrapped_text.push_str(&" ".repeat(boundary.next_indent as usize));
1289                    prev_ix = boundary.ix;
1290                }
1291                wrapped_text.push_str(&line[prev_ix..]);
1292            }
1293            wrapped_text
1294        } else {
1295            unwrapped_text.to_string()
1296        }
1297    }
1298
1299    impl Snapshot {
1300        pub fn text(&self) -> String {
1301            self.text_chunks(0).collect()
1302        }
1303
1304        fn verify_chunks(&mut self, rng: &mut impl Rng) {
1305            for _ in 0..5 {
1306                let mut end_row = rng.gen_range(0..=self.max_point().row());
1307                let start_row = rng.gen_range(0..=end_row);
1308                end_row += 1;
1309
1310                let mut expected_text = self.text_chunks(start_row).collect::<String>();
1311                if expected_text.ends_with("\n") {
1312                    expected_text.push('\n');
1313                }
1314                let mut expected_text = expected_text
1315                    .lines()
1316                    .take((end_row - start_row) as usize)
1317                    .collect::<Vec<_>>()
1318                    .join("\n");
1319                if end_row <= self.max_point().row() {
1320                    expected_text.push('\n');
1321                }
1322
1323                let actual_text = self
1324                    .chunks(start_row..end_row, false)
1325                    .map(|c| c.text)
1326                    .collect::<String>();
1327                assert_eq!(
1328                    expected_text,
1329                    actual_text,
1330                    "chunks != highlighted_chunks for rows {:?}",
1331                    start_row..end_row
1332                );
1333            }
1334        }
1335    }
1336}