buffer.rs

   1pub use crate::{
   2    diagnostic_set::DiagnosticSet,
   3    highlight_map::{HighlightId, HighlightMap},
   4    proto, BracketPair, Grammar, Language, LanguageConfig, LanguageRegistry, PLAIN_TEXT,
   5};
   6use crate::{
   7    diagnostic_set::{DiagnosticEntry, DiagnosticGroup},
   8    language_settings::{language_settings, LanguageSettings},
   9    outline::OutlineItem,
  10    syntax_map::{
  11        SyntaxLayerInfo, SyntaxMap, SyntaxMapCapture, SyntaxMapCaptures, SyntaxSnapshot,
  12        ToTreeSitterPoint,
  13    },
  14    CodeLabel, LanguageScope, Outline,
  15};
  16use anyhow::{anyhow, Result};
  17use clock::ReplicaId;
  18use fs::LineEnding;
  19use futures::FutureExt as _;
  20use gpui::{fonts::HighlightStyle, AppContext, Entity, ModelContext, Task};
  21use lsp::LanguageServerId;
  22use parking_lot::Mutex;
  23use similar::{ChangeTag, TextDiff};
  24use smallvec::SmallVec;
  25use smol::future::yield_now;
  26use std::{
  27    any::Any,
  28    cmp::{self, Ordering},
  29    collections::BTreeMap,
  30    ffi::OsStr,
  31    future::Future,
  32    iter::{self, Iterator, Peekable},
  33    mem,
  34    ops::{Deref, Range},
  35    path::{Path, PathBuf},
  36    str,
  37    sync::Arc,
  38    time::{Duration, Instant, SystemTime, UNIX_EPOCH},
  39    vec,
  40};
  41use sum_tree::TreeMap;
  42use text::operation_queue::OperationQueue;
  43pub use text::{Buffer as TextBuffer, BufferSnapshot as TextBufferSnapshot, *};
  44use theme::SyntaxTheme;
  45#[cfg(any(test, feature = "test-support"))]
  46use util::RandomCharIter;
  47use util::{RangeExt, TryFutureExt as _};
  48
  49#[cfg(any(test, feature = "test-support"))]
  50pub use {tree_sitter_rust, tree_sitter_typescript};
  51
  52pub use lsp::DiagnosticSeverity;
  53
  54pub struct Buffer {
  55    text: TextBuffer,
  56    diff_base: Option<String>,
  57    git_diff: git::diff::BufferDiff,
  58    file: Option<Arc<dyn File>>,
  59    saved_version: clock::Global,
  60    saved_version_fingerprint: RopeFingerprint,
  61    saved_mtime: SystemTime,
  62    transaction_depth: usize,
  63    was_dirty_before_starting_transaction: Option<bool>,
  64    language: Option<Arc<Language>>,
  65    autoindent_requests: Vec<Arc<AutoindentRequest>>,
  66    pending_autoindent: Option<Task<()>>,
  67    sync_parse_timeout: Duration,
  68    syntax_map: Mutex<SyntaxMap>,
  69    parsing_in_background: bool,
  70    parse_count: usize,
  71    diagnostics: SmallVec<[(LanguageServerId, DiagnosticSet); 2]>,
  72    remote_selections: TreeMap<ReplicaId, SelectionSet>,
  73    selections_update_count: usize,
  74    diagnostics_update_count: usize,
  75    diagnostics_timestamp: clock::Lamport,
  76    file_update_count: usize,
  77    git_diff_update_count: usize,
  78    completion_triggers: Vec<String>,
  79    completion_triggers_timestamp: clock::Lamport,
  80    deferred_ops: OperationQueue<Operation>,
  81}
  82
  83pub struct BufferSnapshot {
  84    text: text::BufferSnapshot,
  85    pub git_diff: git::diff::BufferDiff,
  86    pub(crate) syntax: SyntaxSnapshot,
  87    file: Option<Arc<dyn File>>,
  88    diagnostics: SmallVec<[(LanguageServerId, DiagnosticSet); 2]>,
  89    diagnostics_update_count: usize,
  90    file_update_count: usize,
  91    git_diff_update_count: usize,
  92    remote_selections: TreeMap<ReplicaId, SelectionSet>,
  93    selections_update_count: usize,
  94    language: Option<Arc<Language>>,
  95    parse_count: usize,
  96}
  97
  98#[derive(Clone, Copy, Debug, PartialEq, Eq, Default)]
  99pub struct IndentSize {
 100    pub len: u32,
 101    pub kind: IndentKind,
 102}
 103
 104#[derive(Clone, Copy, Debug, PartialEq, Eq, Default)]
 105pub enum IndentKind {
 106    #[default]
 107    Space,
 108    Tab,
 109}
 110
 111#[derive(Copy, Clone, PartialEq, Eq, Debug, Default)]
 112pub enum CursorShape {
 113    #[default]
 114    Bar,
 115    Block,
 116    Underscore,
 117    Hollow,
 118}
 119
 120#[derive(Clone, Debug)]
 121struct SelectionSet {
 122    line_mode: bool,
 123    cursor_shape: CursorShape,
 124    selections: Arc<[Selection<Anchor>]>,
 125    lamport_timestamp: clock::Lamport,
 126}
 127
 128#[derive(Clone, Debug, PartialEq, Eq)]
 129pub struct GroupId {
 130    source: Arc<str>,
 131    id: usize,
 132}
 133
 134#[derive(Clone, Debug, PartialEq, Eq)]
 135pub struct Diagnostic {
 136    pub source: Option<String>,
 137    pub code: Option<String>,
 138    pub severity: DiagnosticSeverity,
 139    pub message: String,
 140    pub group_id: usize,
 141    pub is_valid: bool,
 142    pub is_primary: bool,
 143    pub is_disk_based: bool,
 144    pub is_unnecessary: bool,
 145}
 146
 147#[derive(Clone, Debug)]
 148pub struct Completion {
 149    pub old_range: Range<Anchor>,
 150    pub new_text: String,
 151    pub label: CodeLabel,
 152    pub server_id: LanguageServerId,
 153    pub lsp_completion: lsp::CompletionItem,
 154}
 155
 156#[derive(Clone, Debug)]
 157pub struct CodeAction {
 158    pub server_id: LanguageServerId,
 159    pub range: Range<Anchor>,
 160    pub lsp_action: lsp::CodeAction,
 161}
 162
 163#[derive(Clone, Debug, PartialEq, Eq)]
 164pub enum Operation {
 165    Buffer(text::Operation),
 166
 167    UpdateDiagnostics {
 168        server_id: LanguageServerId,
 169        diagnostics: Arc<[DiagnosticEntry<Anchor>]>,
 170        lamport_timestamp: clock::Lamport,
 171    },
 172
 173    UpdateSelections {
 174        selections: Arc<[Selection<Anchor>]>,
 175        lamport_timestamp: clock::Lamport,
 176        line_mode: bool,
 177        cursor_shape: CursorShape,
 178    },
 179
 180    UpdateCompletionTriggers {
 181        triggers: Vec<String>,
 182        lamport_timestamp: clock::Lamport,
 183    },
 184}
 185
 186#[derive(Clone, Debug, PartialEq, Eq)]
 187pub enum Event {
 188    Operation(Operation),
 189    Edited,
 190    DirtyChanged,
 191    Saved,
 192    FileHandleChanged,
 193    Reloaded,
 194    DiffBaseChanged,
 195    LanguageChanged,
 196    Reparsed,
 197    DiagnosticsUpdated,
 198    Closed,
 199}
 200
 201pub trait File: Send + Sync {
 202    fn as_local(&self) -> Option<&dyn LocalFile>;
 203
 204    fn is_local(&self) -> bool {
 205        self.as_local().is_some()
 206    }
 207
 208    fn mtime(&self) -> SystemTime;
 209
 210    /// Returns the path of this file relative to the worktree's root directory.
 211    fn path(&self) -> &Arc<Path>;
 212
 213    /// Returns the path of this file relative to the worktree's parent directory (this means it
 214    /// includes the name of the worktree's root folder).
 215    fn full_path(&self, cx: &AppContext) -> PathBuf;
 216
 217    /// Returns the last component of this handle's absolute path. If this handle refers to the root
 218    /// of its worktree, then this method will return the name of the worktree itself.
 219    fn file_name<'a>(&'a self, cx: &'a AppContext) -> &'a OsStr;
 220
 221    /// Returns the id of the worktree to which this file belongs.
 222    ///
 223    /// This is needed for looking up project-specific settings.
 224    fn worktree_id(&self) -> usize;
 225
 226    fn is_deleted(&self) -> bool;
 227
 228    fn as_any(&self) -> &dyn Any;
 229
 230    fn to_proto(&self) -> rpc::proto::File;
 231}
 232
 233pub trait LocalFile: File {
 234    /// Returns the absolute path of this file.
 235    fn abs_path(&self, cx: &AppContext) -> PathBuf;
 236
 237    fn load(&self, cx: &AppContext) -> Task<Result<String>>;
 238
 239    fn buffer_reloaded(
 240        &self,
 241        buffer_id: u64,
 242        version: &clock::Global,
 243        fingerprint: RopeFingerprint,
 244        line_ending: LineEnding,
 245        mtime: SystemTime,
 246        cx: &mut AppContext,
 247    );
 248}
 249
 250#[derive(Clone, Debug)]
 251pub enum AutoindentMode {
 252    /// Indent each line of inserted text.
 253    EachLine,
 254    /// Apply the same indentation adjustment to all of the lines
 255    /// in a given insertion.
 256    Block {
 257        /// The original indentation level of the first line of each
 258        /// insertion, if it has been copied.
 259        original_indent_columns: Vec<u32>,
 260    },
 261}
 262
 263#[derive(Clone)]
 264struct AutoindentRequest {
 265    before_edit: BufferSnapshot,
 266    entries: Vec<AutoindentRequestEntry>,
 267    is_block_mode: bool,
 268}
 269
 270#[derive(Clone)]
 271struct AutoindentRequestEntry {
 272    /// A range of the buffer whose indentation should be adjusted.
 273    range: Range<Anchor>,
 274    /// Whether or not these lines should be considered brand new, for the
 275    /// purpose of auto-indent. When text is not new, its indentation will
 276    /// only be adjusted if the suggested indentation level has *changed*
 277    /// since the edit was made.
 278    first_line_is_new: bool,
 279    indent_size: IndentSize,
 280    original_indent_column: Option<u32>,
 281}
 282
 283#[derive(Debug)]
 284struct IndentSuggestion {
 285    basis_row: u32,
 286    delta: Ordering,
 287    within_error: bool,
 288}
 289
 290struct BufferChunkHighlights<'a> {
 291    captures: SyntaxMapCaptures<'a>,
 292    next_capture: Option<SyntaxMapCapture<'a>>,
 293    stack: Vec<(usize, HighlightId)>,
 294    highlight_maps: Vec<HighlightMap>,
 295}
 296
 297pub struct BufferChunks<'a> {
 298    range: Range<usize>,
 299    chunks: text::Chunks<'a>,
 300    diagnostic_endpoints: Peekable<vec::IntoIter<DiagnosticEndpoint>>,
 301    error_depth: usize,
 302    warning_depth: usize,
 303    information_depth: usize,
 304    hint_depth: usize,
 305    unnecessary_depth: usize,
 306    highlights: Option<BufferChunkHighlights<'a>>,
 307}
 308
 309#[derive(Clone, Copy, Debug, Default)]
 310pub struct Chunk<'a> {
 311    pub text: &'a str,
 312    pub syntax_highlight_id: Option<HighlightId>,
 313    pub highlight_style: Option<HighlightStyle>,
 314    pub diagnostic_severity: Option<DiagnosticSeverity>,
 315    pub is_unnecessary: bool,
 316    pub is_tab: bool,
 317}
 318
 319pub struct Diff {
 320    pub(crate) base_version: clock::Global,
 321    line_ending: LineEnding,
 322    edits: Vec<(Range<usize>, Arc<str>)>,
 323}
 324
 325#[derive(Clone, Copy)]
 326pub(crate) struct DiagnosticEndpoint {
 327    offset: usize,
 328    is_start: bool,
 329    severity: DiagnosticSeverity,
 330    is_unnecessary: bool,
 331}
 332
 333#[derive(Copy, Clone, Eq, PartialEq, PartialOrd, Ord, Debug)]
 334pub enum CharKind {
 335    Punctuation,
 336    Whitespace,
 337    Word,
 338}
 339
 340impl CharKind {
 341    pub fn coerce_punctuation(self, treat_punctuation_as_word: bool) -> Self {
 342        if treat_punctuation_as_word && self == CharKind::Punctuation {
 343            CharKind::Word
 344        } else {
 345            self
 346        }
 347    }
 348}
 349
 350impl Buffer {
 351    pub fn new<T: Into<String>>(
 352        replica_id: ReplicaId,
 353        base_text: T,
 354        cx: &mut ModelContext<Self>,
 355    ) -> Self {
 356        Self::build(
 357            TextBuffer::new(replica_id, cx.model_id() as u64, base_text.into()),
 358            None,
 359            None,
 360        )
 361    }
 362
 363    pub fn from_proto(
 364        replica_id: ReplicaId,
 365        message: proto::BufferState,
 366        file: Option<Arc<dyn File>>,
 367    ) -> Result<Self> {
 368        let buffer = TextBuffer::new(replica_id, message.id, message.base_text);
 369        let mut this = Self::build(
 370            buffer,
 371            message.diff_base.map(|text| text.into_boxed_str().into()),
 372            file,
 373        );
 374        this.text.set_line_ending(proto::deserialize_line_ending(
 375            rpc::proto::LineEnding::from_i32(message.line_ending)
 376                .ok_or_else(|| anyhow!("missing line_ending"))?,
 377        ));
 378        this.saved_version = proto::deserialize_version(&message.saved_version);
 379        this.saved_version_fingerprint =
 380            proto::deserialize_fingerprint(&message.saved_version_fingerprint)?;
 381        this.saved_mtime = message
 382            .saved_mtime
 383            .ok_or_else(|| anyhow!("invalid saved_mtime"))?
 384            .into();
 385        Ok(this)
 386    }
 387
 388    pub fn to_proto(&self) -> proto::BufferState {
 389        proto::BufferState {
 390            id: self.remote_id(),
 391            file: self.file.as_ref().map(|f| f.to_proto()),
 392            base_text: self.base_text().to_string(),
 393            diff_base: self.diff_base.as_ref().map(|h| h.to_string()),
 394            line_ending: proto::serialize_line_ending(self.line_ending()) as i32,
 395            saved_version: proto::serialize_version(&self.saved_version),
 396            saved_version_fingerprint: proto::serialize_fingerprint(self.saved_version_fingerprint),
 397            saved_mtime: Some(self.saved_mtime.into()),
 398        }
 399    }
 400
 401    pub fn serialize_ops(
 402        &self,
 403        since: Option<clock::Global>,
 404        cx: &AppContext,
 405    ) -> Task<Vec<proto::Operation>> {
 406        let mut operations = Vec::new();
 407        operations.extend(self.deferred_ops.iter().map(proto::serialize_operation));
 408
 409        operations.extend(self.remote_selections.iter().map(|(_, set)| {
 410            proto::serialize_operation(&Operation::UpdateSelections {
 411                selections: set.selections.clone(),
 412                lamport_timestamp: set.lamport_timestamp,
 413                line_mode: set.line_mode,
 414                cursor_shape: set.cursor_shape,
 415            })
 416        }));
 417
 418        for (server_id, diagnostics) in &self.diagnostics {
 419            operations.push(proto::serialize_operation(&Operation::UpdateDiagnostics {
 420                lamport_timestamp: self.diagnostics_timestamp,
 421                server_id: *server_id,
 422                diagnostics: diagnostics.iter().cloned().collect(),
 423            }));
 424        }
 425
 426        operations.push(proto::serialize_operation(
 427            &Operation::UpdateCompletionTriggers {
 428                triggers: self.completion_triggers.clone(),
 429                lamport_timestamp: self.completion_triggers_timestamp,
 430            },
 431        ));
 432
 433        let text_operations = self.text.operations().clone();
 434        cx.background().spawn(async move {
 435            let since = since.unwrap_or_default();
 436            operations.extend(
 437                text_operations
 438                    .iter()
 439                    .filter(|(_, op)| !since.observed(op.local_timestamp()))
 440                    .map(|(_, op)| proto::serialize_operation(&Operation::Buffer(op.clone()))),
 441            );
 442            operations.sort_unstable_by_key(proto::lamport_timestamp_for_operation);
 443            operations
 444        })
 445    }
 446
 447    pub fn with_language(mut self, language: Arc<Language>, cx: &mut ModelContext<Self>) -> Self {
 448        self.set_language(Some(language), cx);
 449        self
 450    }
 451
 452    pub fn build(
 453        buffer: TextBuffer,
 454        diff_base: Option<String>,
 455        file: Option<Arc<dyn File>>,
 456    ) -> Self {
 457        let saved_mtime = if let Some(file) = file.as_ref() {
 458            file.mtime()
 459        } else {
 460            UNIX_EPOCH
 461        };
 462
 463        Self {
 464            saved_mtime,
 465            saved_version: buffer.version(),
 466            saved_version_fingerprint: buffer.as_rope().fingerprint(),
 467            transaction_depth: 0,
 468            was_dirty_before_starting_transaction: None,
 469            text: buffer,
 470            diff_base,
 471            git_diff: git::diff::BufferDiff::new(),
 472            file,
 473            syntax_map: Mutex::new(SyntaxMap::new()),
 474            parsing_in_background: false,
 475            parse_count: 0,
 476            sync_parse_timeout: Duration::from_millis(1),
 477            autoindent_requests: Default::default(),
 478            pending_autoindent: Default::default(),
 479            language: None,
 480            remote_selections: Default::default(),
 481            selections_update_count: 0,
 482            diagnostics: Default::default(),
 483            diagnostics_update_count: 0,
 484            diagnostics_timestamp: Default::default(),
 485            file_update_count: 0,
 486            git_diff_update_count: 0,
 487            completion_triggers: Default::default(),
 488            completion_triggers_timestamp: Default::default(),
 489            deferred_ops: OperationQueue::new(),
 490        }
 491    }
 492
 493    pub fn snapshot(&self) -> BufferSnapshot {
 494        let text = self.text.snapshot();
 495        let mut syntax_map = self.syntax_map.lock();
 496        syntax_map.interpolate(&text);
 497        let syntax = syntax_map.snapshot();
 498
 499        BufferSnapshot {
 500            text,
 501            syntax,
 502            git_diff: self.git_diff.clone(),
 503            file: self.file.clone(),
 504            remote_selections: self.remote_selections.clone(),
 505            diagnostics: self.diagnostics.clone(),
 506            diagnostics_update_count: self.diagnostics_update_count,
 507            file_update_count: self.file_update_count,
 508            git_diff_update_count: self.git_diff_update_count,
 509            language: self.language.clone(),
 510            parse_count: self.parse_count,
 511            selections_update_count: self.selections_update_count,
 512        }
 513    }
 514
 515    pub fn as_text_snapshot(&self) -> &text::BufferSnapshot {
 516        &self.text
 517    }
 518
 519    pub fn text_snapshot(&self) -> text::BufferSnapshot {
 520        self.text.snapshot()
 521    }
 522
 523    pub fn file(&self) -> Option<&Arc<dyn File>> {
 524        self.file.as_ref()
 525    }
 526
 527    pub fn saved_version(&self) -> &clock::Global {
 528        &self.saved_version
 529    }
 530
 531    pub fn saved_version_fingerprint(&self) -> RopeFingerprint {
 532        self.saved_version_fingerprint
 533    }
 534
 535    pub fn saved_mtime(&self) -> SystemTime {
 536        self.saved_mtime
 537    }
 538
 539    pub fn set_language(&mut self, language: Option<Arc<Language>>, cx: &mut ModelContext<Self>) {
 540        self.syntax_map.lock().clear();
 541        self.language = language;
 542        self.reparse(cx);
 543        cx.emit(Event::LanguageChanged);
 544    }
 545
 546    pub fn set_language_registry(&mut self, language_registry: Arc<LanguageRegistry>) {
 547        self.syntax_map
 548            .lock()
 549            .set_language_registry(language_registry);
 550    }
 551
 552    pub fn did_save(
 553        &mut self,
 554        version: clock::Global,
 555        fingerprint: RopeFingerprint,
 556        mtime: SystemTime,
 557        cx: &mut ModelContext<Self>,
 558    ) {
 559        self.saved_version = version;
 560        self.saved_version_fingerprint = fingerprint;
 561        self.saved_mtime = mtime;
 562        cx.emit(Event::Saved);
 563        cx.notify();
 564    }
 565
 566    pub fn reload(&mut self, cx: &mut ModelContext<Self>) -> Task<Result<Option<Transaction>>> {
 567        cx.spawn(|this, mut cx| async move {
 568            if let Some((new_mtime, new_text)) = this.read_with(&cx, |this, cx| {
 569                let file = this.file.as_ref()?.as_local()?;
 570                Some((file.mtime(), file.load(cx)))
 571            }) {
 572                let new_text = new_text.await?;
 573                let diff = this
 574                    .read_with(&cx, |this, cx| this.diff(new_text, cx))
 575                    .await;
 576                this.update(&mut cx, |this, cx| {
 577                    if this.version() == diff.base_version {
 578                        this.finalize_last_transaction();
 579                        this.apply_diff(diff, cx);
 580                        if let Some(transaction) = this.finalize_last_transaction().cloned() {
 581                            this.did_reload(
 582                                this.version(),
 583                                this.as_rope().fingerprint(),
 584                                this.line_ending(),
 585                                new_mtime,
 586                                cx,
 587                            );
 588                            return Ok(Some(transaction));
 589                        }
 590                    }
 591                    Ok(None)
 592                })
 593            } else {
 594                Ok(None)
 595            }
 596        })
 597    }
 598
 599    pub fn did_reload(
 600        &mut self,
 601        version: clock::Global,
 602        fingerprint: RopeFingerprint,
 603        line_ending: LineEnding,
 604        mtime: SystemTime,
 605        cx: &mut ModelContext<Self>,
 606    ) {
 607        self.saved_version = version;
 608        self.saved_version_fingerprint = fingerprint;
 609        self.text.set_line_ending(line_ending);
 610        self.saved_mtime = mtime;
 611        if let Some(file) = self.file.as_ref().and_then(|f| f.as_local()) {
 612            file.buffer_reloaded(
 613                self.remote_id(),
 614                &self.saved_version,
 615                self.saved_version_fingerprint,
 616                self.line_ending(),
 617                self.saved_mtime,
 618                cx,
 619            );
 620        }
 621        cx.emit(Event::Reloaded);
 622        cx.notify();
 623    }
 624
 625    pub fn file_updated(
 626        &mut self,
 627        new_file: Arc<dyn File>,
 628        cx: &mut ModelContext<Self>,
 629    ) -> Task<()> {
 630        let mut file_changed = false;
 631        let mut task = Task::ready(());
 632
 633        if let Some(old_file) = self.file.as_ref() {
 634            if new_file.path() != old_file.path() {
 635                file_changed = true;
 636            }
 637
 638            if new_file.is_deleted() {
 639                if !old_file.is_deleted() {
 640                    file_changed = true;
 641                    if !self.is_dirty() {
 642                        cx.emit(Event::DirtyChanged);
 643                    }
 644                }
 645            } else {
 646                let new_mtime = new_file.mtime();
 647                if new_mtime != old_file.mtime() {
 648                    file_changed = true;
 649
 650                    if !self.is_dirty() {
 651                        let reload = self.reload(cx).log_err().map(drop);
 652                        task = cx.foreground().spawn(reload);
 653                    }
 654                }
 655            }
 656        } else {
 657            file_changed = true;
 658        };
 659
 660        if file_changed {
 661            self.file_update_count += 1;
 662            cx.emit(Event::FileHandleChanged);
 663            cx.notify();
 664        }
 665        self.file = Some(new_file);
 666        task
 667    }
 668
 669    pub fn diff_base(&self) -> Option<&str> {
 670        self.diff_base.as_deref()
 671    }
 672
 673    pub fn set_diff_base(&mut self, diff_base: Option<String>, cx: &mut ModelContext<Self>) {
 674        self.diff_base = diff_base;
 675        self.git_diff_recalc(cx);
 676        cx.emit(Event::DiffBaseChanged);
 677    }
 678
 679    pub fn git_diff_recalc(&mut self, cx: &mut ModelContext<Self>) -> Option<Task<()>> {
 680        let diff_base = self.diff_base.clone()?; // TODO: Make this an Arc
 681        let snapshot = self.snapshot();
 682
 683        let mut diff = self.git_diff.clone();
 684        let diff = cx.background().spawn(async move {
 685            diff.update(&diff_base, &snapshot).await;
 686            diff
 687        });
 688
 689        let handle = cx.weak_handle();
 690        Some(cx.spawn_weak(|_, mut cx| async move {
 691            let buffer_diff = diff.await;
 692            if let Some(this) = handle.upgrade(&mut cx) {
 693                this.update(&mut cx, |this, _| {
 694                    this.git_diff = buffer_diff;
 695                    this.git_diff_update_count += 1;
 696                })
 697            }
 698        }))
 699    }
 700
 701    pub fn close(&mut self, cx: &mut ModelContext<Self>) {
 702        cx.emit(Event::Closed);
 703    }
 704
 705    pub fn language(&self) -> Option<&Arc<Language>> {
 706        self.language.as_ref()
 707    }
 708
 709    pub fn language_at<D: ToOffset>(&self, position: D) -> Option<Arc<Language>> {
 710        let offset = position.to_offset(self);
 711        self.syntax_map
 712            .lock()
 713            .layers_for_range(offset..offset, &self.text)
 714            .last()
 715            .map(|info| info.language.clone())
 716            .or_else(|| self.language.clone())
 717    }
 718
 719    pub fn parse_count(&self) -> usize {
 720        self.parse_count
 721    }
 722
 723    pub fn selections_update_count(&self) -> usize {
 724        self.selections_update_count
 725    }
 726
 727    pub fn diagnostics_update_count(&self) -> usize {
 728        self.diagnostics_update_count
 729    }
 730
 731    pub fn file_update_count(&self) -> usize {
 732        self.file_update_count
 733    }
 734
 735    pub fn git_diff_update_count(&self) -> usize {
 736        self.git_diff_update_count
 737    }
 738
 739    #[cfg(any(test, feature = "test-support"))]
 740    pub fn is_parsing(&self) -> bool {
 741        self.parsing_in_background
 742    }
 743
 744    pub fn contains_unknown_injections(&self) -> bool {
 745        self.syntax_map.lock().contains_unknown_injections()
 746    }
 747
 748    #[cfg(test)]
 749    pub fn set_sync_parse_timeout(&mut self, timeout: Duration) {
 750        self.sync_parse_timeout = timeout;
 751    }
 752
 753    /// Called after an edit to synchronize the buffer's main parse tree with
 754    /// the buffer's new underlying state.
 755    ///
 756    /// Locks the syntax map and interpolates the edits since the last reparse
 757    /// into the foreground syntax tree.
 758    ///
 759    /// Then takes a stable snapshot of the syntax map before unlocking it.
 760    /// The snapshot with the interpolated edits is sent to a background thread,
 761    /// where we ask Tree-sitter to perform an incremental parse.
 762    ///
 763    /// Meanwhile, in the foreground, we block the main thread for up to 1ms
 764    /// waiting on the parse to complete. As soon as it completes, we proceed
 765    /// synchronously, unless a 1ms timeout elapses.
 766    ///
 767    /// If we time out waiting on the parse, we spawn a second task waiting
 768    /// until the parse does complete and return with the interpolated tree still
 769    /// in the foreground. When the background parse completes, call back into
 770    /// the main thread and assign the foreground parse state.
 771    ///
 772    /// If the buffer or grammar changed since the start of the background parse,
 773    /// initiate an additional reparse recursively. To avoid concurrent parses
 774    /// for the same buffer, we only initiate a new parse if we are not already
 775    /// parsing in the background.
 776    pub fn reparse(&mut self, cx: &mut ModelContext<Self>) {
 777        if self.parsing_in_background {
 778            return;
 779        }
 780        let language = if let Some(language) = self.language.clone() {
 781            language
 782        } else {
 783            return;
 784        };
 785
 786        let text = self.text_snapshot();
 787        let parsed_version = self.version();
 788
 789        let mut syntax_map = self.syntax_map.lock();
 790        syntax_map.interpolate(&text);
 791        let language_registry = syntax_map.language_registry();
 792        let mut syntax_snapshot = syntax_map.snapshot();
 793        drop(syntax_map);
 794
 795        let parse_task = cx.background().spawn({
 796            let language = language.clone();
 797            let language_registry = language_registry.clone();
 798            async move {
 799                syntax_snapshot.reparse(&text, language_registry, language);
 800                syntax_snapshot
 801            }
 802        });
 803
 804        match cx
 805            .background()
 806            .block_with_timeout(self.sync_parse_timeout, parse_task)
 807        {
 808            Ok(new_syntax_snapshot) => {
 809                self.did_finish_parsing(new_syntax_snapshot, cx);
 810                return;
 811            }
 812            Err(parse_task) => {
 813                self.parsing_in_background = true;
 814                cx.spawn(move |this, mut cx| async move {
 815                    let new_syntax_map = parse_task.await;
 816                    this.update(&mut cx, move |this, cx| {
 817                        let grammar_changed =
 818                            this.language.as_ref().map_or(true, |current_language| {
 819                                !Arc::ptr_eq(&language, current_language)
 820                            });
 821                        let language_registry_changed = new_syntax_map
 822                            .contains_unknown_injections()
 823                            && language_registry.map_or(false, |registry| {
 824                                registry.version() != new_syntax_map.language_registry_version()
 825                            });
 826                        let parse_again = language_registry_changed
 827                            || grammar_changed
 828                            || this.version.changed_since(&parsed_version);
 829                        this.did_finish_parsing(new_syntax_map, cx);
 830                        this.parsing_in_background = false;
 831                        if parse_again {
 832                            this.reparse(cx);
 833                        }
 834                    });
 835                })
 836                .detach();
 837            }
 838        }
 839    }
 840
 841    fn did_finish_parsing(&mut self, syntax_snapshot: SyntaxSnapshot, cx: &mut ModelContext<Self>) {
 842        self.parse_count += 1;
 843        self.syntax_map.lock().did_parse(syntax_snapshot);
 844        self.request_autoindent(cx);
 845        cx.emit(Event::Reparsed);
 846        cx.notify();
 847    }
 848
 849    pub fn update_diagnostics(
 850        &mut self,
 851        server_id: LanguageServerId,
 852        diagnostics: DiagnosticSet,
 853        cx: &mut ModelContext<Self>,
 854    ) {
 855        let lamport_timestamp = self.text.lamport_clock.tick();
 856        let op = Operation::UpdateDiagnostics {
 857            server_id,
 858            diagnostics: diagnostics.iter().cloned().collect(),
 859            lamport_timestamp,
 860        };
 861        self.apply_diagnostic_update(server_id, diagnostics, lamport_timestamp, cx);
 862        self.send_operation(op, cx);
 863    }
 864
 865    fn request_autoindent(&mut self, cx: &mut ModelContext<Self>) {
 866        if let Some(indent_sizes) = self.compute_autoindents() {
 867            let indent_sizes = cx.background().spawn(indent_sizes);
 868            match cx
 869                .background()
 870                .block_with_timeout(Duration::from_micros(500), indent_sizes)
 871            {
 872                Ok(indent_sizes) => self.apply_autoindents(indent_sizes, cx),
 873                Err(indent_sizes) => {
 874                    self.pending_autoindent = Some(cx.spawn(|this, mut cx| async move {
 875                        let indent_sizes = indent_sizes.await;
 876                        this.update(&mut cx, |this, cx| {
 877                            this.apply_autoindents(indent_sizes, cx);
 878                        });
 879                    }));
 880                }
 881            }
 882        } else {
 883            self.autoindent_requests.clear();
 884        }
 885    }
 886
 887    fn compute_autoindents(&self) -> Option<impl Future<Output = BTreeMap<u32, IndentSize>>> {
 888        let max_rows_between_yields = 100;
 889        let snapshot = self.snapshot();
 890        if snapshot.syntax.is_empty() || self.autoindent_requests.is_empty() {
 891            return None;
 892        }
 893
 894        let autoindent_requests = self.autoindent_requests.clone();
 895        Some(async move {
 896            let mut indent_sizes = BTreeMap::new();
 897            for request in autoindent_requests {
 898                // Resolve each edited range to its row in the current buffer and in the
 899                // buffer before this batch of edits.
 900                let mut row_ranges = Vec::new();
 901                let mut old_to_new_rows = BTreeMap::new();
 902                let mut language_indent_sizes_by_new_row = Vec::new();
 903                for entry in &request.entries {
 904                    let position = entry.range.start;
 905                    let new_row = position.to_point(&snapshot).row;
 906                    let new_end_row = entry.range.end.to_point(&snapshot).row + 1;
 907                    language_indent_sizes_by_new_row.push((new_row, entry.indent_size));
 908
 909                    if !entry.first_line_is_new {
 910                        let old_row = position.to_point(&request.before_edit).row;
 911                        old_to_new_rows.insert(old_row, new_row);
 912                    }
 913                    row_ranges.push((new_row..new_end_row, entry.original_indent_column));
 914                }
 915
 916                // Build a map containing the suggested indentation for each of the edited lines
 917                // with respect to the state of the buffer before these edits. This map is keyed
 918                // by the rows for these lines in the current state of the buffer.
 919                let mut old_suggestions = BTreeMap::<u32, (IndentSize, bool)>::default();
 920                let old_edited_ranges =
 921                    contiguous_ranges(old_to_new_rows.keys().copied(), max_rows_between_yields);
 922                let mut language_indent_sizes = language_indent_sizes_by_new_row.iter().peekable();
 923                let mut language_indent_size = IndentSize::default();
 924                for old_edited_range in old_edited_ranges {
 925                    let suggestions = request
 926                        .before_edit
 927                        .suggest_autoindents(old_edited_range.clone())
 928                        .into_iter()
 929                        .flatten();
 930                    for (old_row, suggestion) in old_edited_range.zip(suggestions) {
 931                        if let Some(suggestion) = suggestion {
 932                            let new_row = *old_to_new_rows.get(&old_row).unwrap();
 933
 934                            // Find the indent size based on the language for this row.
 935                            while let Some((row, size)) = language_indent_sizes.peek() {
 936                                if *row > new_row {
 937                                    break;
 938                                }
 939                                language_indent_size = *size;
 940                                language_indent_sizes.next();
 941                            }
 942
 943                            let suggested_indent = old_to_new_rows
 944                                .get(&suggestion.basis_row)
 945                                .and_then(|from_row| {
 946                                    Some(old_suggestions.get(from_row).copied()?.0)
 947                                })
 948                                .unwrap_or_else(|| {
 949                                    request
 950                                        .before_edit
 951                                        .indent_size_for_line(suggestion.basis_row)
 952                                })
 953                                .with_delta(suggestion.delta, language_indent_size);
 954                            old_suggestions
 955                                .insert(new_row, (suggested_indent, suggestion.within_error));
 956                        }
 957                    }
 958                    yield_now().await;
 959                }
 960
 961                // In block mode, only compute indentation suggestions for the first line
 962                // of each insertion. Otherwise, compute suggestions for every inserted line.
 963                let new_edited_row_ranges = contiguous_ranges(
 964                    row_ranges.iter().flat_map(|(range, _)| {
 965                        if request.is_block_mode {
 966                            range.start..range.start + 1
 967                        } else {
 968                            range.clone()
 969                        }
 970                    }),
 971                    max_rows_between_yields,
 972                );
 973
 974                // Compute new suggestions for each line, but only include them in the result
 975                // if they differ from the old suggestion for that line.
 976                let mut language_indent_sizes = language_indent_sizes_by_new_row.iter().peekable();
 977                let mut language_indent_size = IndentSize::default();
 978                for new_edited_row_range in new_edited_row_ranges {
 979                    let suggestions = snapshot
 980                        .suggest_autoindents(new_edited_row_range.clone())
 981                        .into_iter()
 982                        .flatten();
 983                    for (new_row, suggestion) in new_edited_row_range.zip(suggestions) {
 984                        if let Some(suggestion) = suggestion {
 985                            // Find the indent size based on the language for this row.
 986                            while let Some((row, size)) = language_indent_sizes.peek() {
 987                                if *row > new_row {
 988                                    break;
 989                                }
 990                                language_indent_size = *size;
 991                                language_indent_sizes.next();
 992                            }
 993
 994                            let suggested_indent = indent_sizes
 995                                .get(&suggestion.basis_row)
 996                                .copied()
 997                                .unwrap_or_else(|| {
 998                                    snapshot.indent_size_for_line(suggestion.basis_row)
 999                                })
1000                                .with_delta(suggestion.delta, language_indent_size);
1001                            if old_suggestions.get(&new_row).map_or(
1002                                true,
1003                                |(old_indentation, was_within_error)| {
1004                                    suggested_indent != *old_indentation
1005                                        && (!suggestion.within_error || *was_within_error)
1006                                },
1007                            ) {
1008                                indent_sizes.insert(new_row, suggested_indent);
1009                            }
1010                        }
1011                    }
1012                    yield_now().await;
1013                }
1014
1015                // For each block of inserted text, adjust the indentation of the remaining
1016                // lines of the block by the same amount as the first line was adjusted.
1017                if request.is_block_mode {
1018                    for (row_range, original_indent_column) in
1019                        row_ranges
1020                            .into_iter()
1021                            .filter_map(|(range, original_indent_column)| {
1022                                if range.len() > 1 {
1023                                    Some((range, original_indent_column?))
1024                                } else {
1025                                    None
1026                                }
1027                            })
1028                    {
1029                        let new_indent = indent_sizes
1030                            .get(&row_range.start)
1031                            .copied()
1032                            .unwrap_or_else(|| snapshot.indent_size_for_line(row_range.start));
1033                        let delta = new_indent.len as i64 - original_indent_column as i64;
1034                        if delta != 0 {
1035                            for row in row_range.skip(1) {
1036                                indent_sizes.entry(row).or_insert_with(|| {
1037                                    let mut size = snapshot.indent_size_for_line(row);
1038                                    if size.kind == new_indent.kind {
1039                                        match delta.cmp(&0) {
1040                                            Ordering::Greater => size.len += delta as u32,
1041                                            Ordering::Less => {
1042                                                size.len = size.len.saturating_sub(-delta as u32)
1043                                            }
1044                                            Ordering::Equal => {}
1045                                        }
1046                                    }
1047                                    size
1048                                });
1049                            }
1050                        }
1051                    }
1052                }
1053            }
1054
1055            indent_sizes
1056        })
1057    }
1058
1059    fn apply_autoindents(
1060        &mut self,
1061        indent_sizes: BTreeMap<u32, IndentSize>,
1062        cx: &mut ModelContext<Self>,
1063    ) {
1064        self.autoindent_requests.clear();
1065
1066        let edits: Vec<_> = indent_sizes
1067            .into_iter()
1068            .filter_map(|(row, indent_size)| {
1069                let current_size = indent_size_for_line(self, row);
1070                Self::edit_for_indent_size_adjustment(row, current_size, indent_size)
1071            })
1072            .collect();
1073
1074        self.edit(edits, None, cx);
1075    }
1076
1077    // Create a minimal edit that will cause the the given row to be indented
1078    // with the given size. After applying this edit, the length of the line
1079    // will always be at least `new_size.len`.
1080    pub fn edit_for_indent_size_adjustment(
1081        row: u32,
1082        current_size: IndentSize,
1083        new_size: IndentSize,
1084    ) -> Option<(Range<Point>, String)> {
1085        if new_size.kind != current_size.kind {
1086            Some((
1087                Point::new(row, 0)..Point::new(row, current_size.len),
1088                iter::repeat(new_size.char())
1089                    .take(new_size.len as usize)
1090                    .collect::<String>(),
1091            ))
1092        } else {
1093            match new_size.len.cmp(&current_size.len) {
1094                Ordering::Greater => {
1095                    let point = Point::new(row, 0);
1096                    Some((
1097                        point..point,
1098                        iter::repeat(new_size.char())
1099                            .take((new_size.len - current_size.len) as usize)
1100                            .collect::<String>(),
1101                    ))
1102                }
1103
1104                Ordering::Less => Some((
1105                    Point::new(row, 0)..Point::new(row, current_size.len - new_size.len),
1106                    String::new(),
1107                )),
1108
1109                Ordering::Equal => None,
1110            }
1111        }
1112    }
1113
1114    pub fn diff(&self, mut new_text: String, cx: &AppContext) -> Task<Diff> {
1115        let old_text = self.as_rope().clone();
1116        let base_version = self.version();
1117        cx.background().spawn(async move {
1118            let old_text = old_text.to_string();
1119            let line_ending = LineEnding::detect(&new_text);
1120            LineEnding::normalize(&mut new_text);
1121            let diff = TextDiff::from_chars(old_text.as_str(), new_text.as_str());
1122            let mut edits = Vec::new();
1123            let mut offset = 0;
1124            let empty: Arc<str> = "".into();
1125            for change in diff.iter_all_changes() {
1126                let value = change.value();
1127                let end_offset = offset + value.len();
1128                match change.tag() {
1129                    ChangeTag::Equal => {
1130                        offset = end_offset;
1131                    }
1132                    ChangeTag::Delete => {
1133                        edits.push((offset..end_offset, empty.clone()));
1134                        offset = end_offset;
1135                    }
1136                    ChangeTag::Insert => {
1137                        edits.push((offset..offset, value.into()));
1138                    }
1139                }
1140            }
1141            Diff {
1142                base_version,
1143                line_ending,
1144                edits,
1145            }
1146        })
1147    }
1148
1149    /// Spawn a background task that searches the buffer for any whitespace
1150    /// at the ends of a lines, and returns a `Diff` that removes that whitespace.
1151    pub fn remove_trailing_whitespace(&self, cx: &AppContext) -> Task<Diff> {
1152        let old_text = self.as_rope().clone();
1153        let line_ending = self.line_ending();
1154        let base_version = self.version();
1155        cx.background().spawn(async move {
1156            let ranges = trailing_whitespace_ranges(&old_text);
1157            let empty = Arc::<str>::from("");
1158            Diff {
1159                base_version,
1160                line_ending,
1161                edits: ranges
1162                    .into_iter()
1163                    .map(|range| (range, empty.clone()))
1164                    .collect(),
1165            }
1166        })
1167    }
1168
1169    /// Ensure that the buffer ends with a single newline character, and
1170    /// no other whitespace.
1171    pub fn ensure_final_newline(&mut self, cx: &mut ModelContext<Self>) {
1172        let len = self.len();
1173        let mut offset = len;
1174        for chunk in self.as_rope().reversed_chunks_in_range(0..len) {
1175            let non_whitespace_len = chunk
1176                .trim_end_matches(|c: char| c.is_ascii_whitespace())
1177                .len();
1178            offset -= chunk.len();
1179            offset += non_whitespace_len;
1180            if non_whitespace_len != 0 {
1181                if offset == len - 1 && chunk.get(non_whitespace_len..) == Some("\n") {
1182                    return;
1183                }
1184                break;
1185            }
1186        }
1187        self.edit([(offset..len, "\n")], None, cx);
1188    }
1189
1190    /// Apply a diff to the buffer. If the buffer has changed since the given diff was
1191    /// calculated, then adjust the diff to account for those changes, and discard any
1192    /// parts of the diff that conflict with those changes.
1193    pub fn apply_diff(&mut self, diff: Diff, cx: &mut ModelContext<Self>) -> Option<TransactionId> {
1194        // Check for any edits to the buffer that have occurred since this diff
1195        // was computed.
1196        let snapshot = self.snapshot();
1197        let mut edits_since = snapshot.edits_since::<usize>(&diff.base_version).peekable();
1198        let mut delta = 0;
1199        let adjusted_edits = diff.edits.into_iter().filter_map(|(range, new_text)| {
1200            while let Some(edit_since) = edits_since.peek() {
1201                // If the edit occurs after a diff hunk, then it does not
1202                // affect that hunk.
1203                if edit_since.old.start > range.end {
1204                    break;
1205                }
1206                // If the edit precedes the diff hunk, then adjust the hunk
1207                // to reflect the edit.
1208                else if edit_since.old.end < range.start {
1209                    delta += edit_since.new_len() as i64 - edit_since.old_len() as i64;
1210                    edits_since.next();
1211                }
1212                // If the edit intersects a diff hunk, then discard that hunk.
1213                else {
1214                    return None;
1215                }
1216            }
1217
1218            let start = (range.start as i64 + delta) as usize;
1219            let end = (range.end as i64 + delta) as usize;
1220            Some((start..end, new_text))
1221        });
1222
1223        self.start_transaction();
1224        self.text.set_line_ending(diff.line_ending);
1225        self.edit(adjusted_edits, None, cx);
1226        self.end_transaction(cx)
1227    }
1228
1229    pub fn is_dirty(&self) -> bool {
1230        self.saved_version_fingerprint != self.as_rope().fingerprint()
1231            || self.file.as_ref().map_or(false, |file| file.is_deleted())
1232    }
1233
1234    pub fn has_conflict(&self) -> bool {
1235        self.saved_version_fingerprint != self.as_rope().fingerprint()
1236            && self
1237                .file
1238                .as_ref()
1239                .map_or(false, |file| file.mtime() > self.saved_mtime)
1240    }
1241
1242    pub fn subscribe(&mut self) -> Subscription {
1243        self.text.subscribe()
1244    }
1245
1246    pub fn start_transaction(&mut self) -> Option<TransactionId> {
1247        self.start_transaction_at(Instant::now())
1248    }
1249
1250    pub fn start_transaction_at(&mut self, now: Instant) -> Option<TransactionId> {
1251        self.transaction_depth += 1;
1252        if self.was_dirty_before_starting_transaction.is_none() {
1253            self.was_dirty_before_starting_transaction = Some(self.is_dirty());
1254        }
1255        self.text.start_transaction_at(now)
1256    }
1257
1258    pub fn end_transaction(&mut self, cx: &mut ModelContext<Self>) -> Option<TransactionId> {
1259        self.end_transaction_at(Instant::now(), cx)
1260    }
1261
1262    pub fn end_transaction_at(
1263        &mut self,
1264        now: Instant,
1265        cx: &mut ModelContext<Self>,
1266    ) -> Option<TransactionId> {
1267        assert!(self.transaction_depth > 0);
1268        self.transaction_depth -= 1;
1269        let was_dirty = if self.transaction_depth == 0 {
1270            self.was_dirty_before_starting_transaction.take().unwrap()
1271        } else {
1272            false
1273        };
1274        if let Some((transaction_id, start_version)) = self.text.end_transaction_at(now) {
1275            self.did_edit(&start_version, was_dirty, cx);
1276            Some(transaction_id)
1277        } else {
1278            None
1279        }
1280    }
1281
1282    pub fn push_transaction(&mut self, transaction: Transaction, now: Instant) {
1283        self.text.push_transaction(transaction, now);
1284    }
1285
1286    pub fn finalize_last_transaction(&mut self) -> Option<&Transaction> {
1287        self.text.finalize_last_transaction()
1288    }
1289
1290    pub fn group_until_transaction(&mut self, transaction_id: TransactionId) {
1291        self.text.group_until_transaction(transaction_id);
1292    }
1293
1294    pub fn forget_transaction(&mut self, transaction_id: TransactionId) {
1295        self.text.forget_transaction(transaction_id);
1296    }
1297
1298    pub fn wait_for_edits(
1299        &mut self,
1300        edit_ids: impl IntoIterator<Item = clock::Local>,
1301    ) -> impl Future<Output = Result<()>> {
1302        self.text.wait_for_edits(edit_ids)
1303    }
1304
1305    pub fn wait_for_anchors(
1306        &mut self,
1307        anchors: impl IntoIterator<Item = Anchor>,
1308    ) -> impl 'static + Future<Output = Result<()>> {
1309        self.text.wait_for_anchors(anchors)
1310    }
1311
1312    pub fn wait_for_version(&mut self, version: clock::Global) -> impl Future<Output = Result<()>> {
1313        self.text.wait_for_version(version)
1314    }
1315
1316    pub fn give_up_waiting(&mut self) {
1317        self.text.give_up_waiting();
1318    }
1319
1320    pub fn set_active_selections(
1321        &mut self,
1322        selections: Arc<[Selection<Anchor>]>,
1323        line_mode: bool,
1324        cursor_shape: CursorShape,
1325        cx: &mut ModelContext<Self>,
1326    ) {
1327        let lamport_timestamp = self.text.lamport_clock.tick();
1328        self.remote_selections.insert(
1329            self.text.replica_id(),
1330            SelectionSet {
1331                selections: selections.clone(),
1332                lamport_timestamp,
1333                line_mode,
1334                cursor_shape,
1335            },
1336        );
1337        self.send_operation(
1338            Operation::UpdateSelections {
1339                selections,
1340                line_mode,
1341                lamport_timestamp,
1342                cursor_shape,
1343            },
1344            cx,
1345        );
1346    }
1347
1348    pub fn remove_active_selections(&mut self, cx: &mut ModelContext<Self>) {
1349        if self
1350            .remote_selections
1351            .get(&self.text.replica_id())
1352            .map_or(true, |set| !set.selections.is_empty())
1353        {
1354            self.set_active_selections(Arc::from([]), false, Default::default(), cx);
1355        }
1356    }
1357
1358    pub fn set_text<T>(&mut self, text: T, cx: &mut ModelContext<Self>) -> Option<clock::Local>
1359    where
1360        T: Into<Arc<str>>,
1361    {
1362        self.autoindent_requests.clear();
1363        self.edit([(0..self.len(), text)], None, cx)
1364    }
1365
1366    pub fn edit<I, S, T>(
1367        &mut self,
1368        edits_iter: I,
1369        autoindent_mode: Option<AutoindentMode>,
1370        cx: &mut ModelContext<Self>,
1371    ) -> Option<clock::Local>
1372    where
1373        I: IntoIterator<Item = (Range<S>, T)>,
1374        S: ToOffset,
1375        T: Into<Arc<str>>,
1376    {
1377        // Skip invalid edits and coalesce contiguous ones.
1378        let mut edits: Vec<(Range<usize>, Arc<str>)> = Vec::new();
1379        for (range, new_text) in edits_iter {
1380            let mut range = range.start.to_offset(self)..range.end.to_offset(self);
1381            if range.start > range.end {
1382                mem::swap(&mut range.start, &mut range.end);
1383            }
1384            let new_text = new_text.into();
1385            if !new_text.is_empty() || !range.is_empty() {
1386                if let Some((prev_range, prev_text)) = edits.last_mut() {
1387                    if prev_range.end >= range.start {
1388                        prev_range.end = cmp::max(prev_range.end, range.end);
1389                        *prev_text = format!("{prev_text}{new_text}").into();
1390                    } else {
1391                        edits.push((range, new_text));
1392                    }
1393                } else {
1394                    edits.push((range, new_text));
1395                }
1396            }
1397        }
1398        if edits.is_empty() {
1399            return None;
1400        }
1401
1402        self.start_transaction();
1403        self.pending_autoindent.take();
1404        let autoindent_request = autoindent_mode
1405            .and_then(|mode| self.language.as_ref().map(|_| (self.snapshot(), mode)));
1406
1407        let edit_operation = self.text.edit(edits.iter().cloned());
1408        let edit_id = edit_operation.local_timestamp();
1409
1410        if let Some((before_edit, mode)) = autoindent_request {
1411            let mut delta = 0isize;
1412            let entries = edits
1413                .into_iter()
1414                .enumerate()
1415                .zip(&edit_operation.as_edit().unwrap().new_text)
1416                .map(|((ix, (range, _)), new_text)| {
1417                    let new_text_length = new_text.len();
1418                    let old_start = range.start.to_point(&before_edit);
1419                    let new_start = (delta + range.start as isize) as usize;
1420                    delta += new_text_length as isize - (range.end as isize - range.start as isize);
1421
1422                    let mut range_of_insertion_to_indent = 0..new_text_length;
1423                    let mut first_line_is_new = false;
1424                    let mut original_indent_column = None;
1425
1426                    // When inserting an entire line at the beginning of an existing line,
1427                    // treat the insertion as new.
1428                    if new_text.contains('\n')
1429                        && old_start.column <= before_edit.indent_size_for_line(old_start.row).len
1430                    {
1431                        first_line_is_new = true;
1432                    }
1433
1434                    // When inserting text starting with a newline, avoid auto-indenting the
1435                    // previous line.
1436                    if new_text.starts_with('\n') {
1437                        range_of_insertion_to_indent.start += 1;
1438                        first_line_is_new = true;
1439                    }
1440
1441                    // Avoid auto-indenting after the insertion.
1442                    if let AutoindentMode::Block {
1443                        original_indent_columns,
1444                    } = &mode
1445                    {
1446                        original_indent_column =
1447                            Some(original_indent_columns.get(ix).copied().unwrap_or_else(|| {
1448                                indent_size_for_text(
1449                                    new_text[range_of_insertion_to_indent.clone()].chars(),
1450                                )
1451                                .len
1452                            }));
1453                        if new_text[range_of_insertion_to_indent.clone()].ends_with('\n') {
1454                            range_of_insertion_to_indent.end -= 1;
1455                        }
1456                    }
1457
1458                    AutoindentRequestEntry {
1459                        first_line_is_new,
1460                        original_indent_column,
1461                        indent_size: before_edit.language_indent_size_at(range.start, cx),
1462                        range: self.anchor_before(new_start + range_of_insertion_to_indent.start)
1463                            ..self.anchor_after(new_start + range_of_insertion_to_indent.end),
1464                    }
1465                })
1466                .collect();
1467
1468            self.autoindent_requests.push(Arc::new(AutoindentRequest {
1469                before_edit,
1470                entries,
1471                is_block_mode: matches!(mode, AutoindentMode::Block { .. }),
1472            }));
1473        }
1474
1475        self.end_transaction(cx);
1476        self.send_operation(Operation::Buffer(edit_operation), cx);
1477        Some(edit_id)
1478    }
1479
1480    fn did_edit(
1481        &mut self,
1482        old_version: &clock::Global,
1483        was_dirty: bool,
1484        cx: &mut ModelContext<Self>,
1485    ) {
1486        if self.edits_since::<usize>(old_version).next().is_none() {
1487            return;
1488        }
1489
1490        self.reparse(cx);
1491
1492        cx.emit(Event::Edited);
1493        if was_dirty != self.is_dirty() {
1494            cx.emit(Event::DirtyChanged);
1495        }
1496        cx.notify();
1497    }
1498
1499    pub fn apply_ops<I: IntoIterator<Item = Operation>>(
1500        &mut self,
1501        ops: I,
1502        cx: &mut ModelContext<Self>,
1503    ) -> Result<()> {
1504        self.pending_autoindent.take();
1505        let was_dirty = self.is_dirty();
1506        let old_version = self.version.clone();
1507        let mut deferred_ops = Vec::new();
1508        let buffer_ops = ops
1509            .into_iter()
1510            .filter_map(|op| match op {
1511                Operation::Buffer(op) => Some(op),
1512                _ => {
1513                    if self.can_apply_op(&op) {
1514                        self.apply_op(op, cx);
1515                    } else {
1516                        deferred_ops.push(op);
1517                    }
1518                    None
1519                }
1520            })
1521            .collect::<Vec<_>>();
1522        self.text.apply_ops(buffer_ops)?;
1523        self.deferred_ops.insert(deferred_ops);
1524        self.flush_deferred_ops(cx);
1525        self.did_edit(&old_version, was_dirty, cx);
1526        // Notify independently of whether the buffer was edited as the operations could include a
1527        // selection update.
1528        cx.notify();
1529        Ok(())
1530    }
1531
1532    fn flush_deferred_ops(&mut self, cx: &mut ModelContext<Self>) {
1533        let mut deferred_ops = Vec::new();
1534        for op in self.deferred_ops.drain().iter().cloned() {
1535            if self.can_apply_op(&op) {
1536                self.apply_op(op, cx);
1537            } else {
1538                deferred_ops.push(op);
1539            }
1540        }
1541        self.deferred_ops.insert(deferred_ops);
1542    }
1543
1544    fn can_apply_op(&self, operation: &Operation) -> bool {
1545        match operation {
1546            Operation::Buffer(_) => {
1547                unreachable!("buffer operations should never be applied at this layer")
1548            }
1549            Operation::UpdateDiagnostics {
1550                diagnostics: diagnostic_set,
1551                ..
1552            } => diagnostic_set.iter().all(|diagnostic| {
1553                self.text.can_resolve(&diagnostic.range.start)
1554                    && self.text.can_resolve(&diagnostic.range.end)
1555            }),
1556            Operation::UpdateSelections { selections, .. } => selections
1557                .iter()
1558                .all(|s| self.can_resolve(&s.start) && self.can_resolve(&s.end)),
1559            Operation::UpdateCompletionTriggers { .. } => true,
1560        }
1561    }
1562
1563    fn apply_op(&mut self, operation: Operation, cx: &mut ModelContext<Self>) {
1564        match operation {
1565            Operation::Buffer(_) => {
1566                unreachable!("buffer operations should never be applied at this layer")
1567            }
1568            Operation::UpdateDiagnostics {
1569                server_id,
1570                diagnostics: diagnostic_set,
1571                lamport_timestamp,
1572            } => {
1573                let snapshot = self.snapshot();
1574                self.apply_diagnostic_update(
1575                    server_id,
1576                    DiagnosticSet::from_sorted_entries(diagnostic_set.iter().cloned(), &snapshot),
1577                    lamport_timestamp,
1578                    cx,
1579                );
1580            }
1581            Operation::UpdateSelections {
1582                selections,
1583                lamport_timestamp,
1584                line_mode,
1585                cursor_shape,
1586            } => {
1587                if let Some(set) = self.remote_selections.get(&lamport_timestamp.replica_id) {
1588                    if set.lamport_timestamp > lamport_timestamp {
1589                        return;
1590                    }
1591                }
1592
1593                self.remote_selections.insert(
1594                    lamport_timestamp.replica_id,
1595                    SelectionSet {
1596                        selections,
1597                        lamport_timestamp,
1598                        line_mode,
1599                        cursor_shape,
1600                    },
1601                );
1602                self.text.lamport_clock.observe(lamport_timestamp);
1603                self.selections_update_count += 1;
1604            }
1605            Operation::UpdateCompletionTriggers {
1606                triggers,
1607                lamport_timestamp,
1608            } => {
1609                self.completion_triggers = triggers;
1610                self.text.lamport_clock.observe(lamport_timestamp);
1611            }
1612        }
1613    }
1614
1615    fn apply_diagnostic_update(
1616        &mut self,
1617        server_id: LanguageServerId,
1618        diagnostics: DiagnosticSet,
1619        lamport_timestamp: clock::Lamport,
1620        cx: &mut ModelContext<Self>,
1621    ) {
1622        if lamport_timestamp > self.diagnostics_timestamp {
1623            let ix = self.diagnostics.binary_search_by_key(&server_id, |e| e.0);
1624            if diagnostics.len() == 0 {
1625                if let Ok(ix) = ix {
1626                    self.diagnostics.remove(ix);
1627                }
1628            } else {
1629                match ix {
1630                    Err(ix) => self.diagnostics.insert(ix, (server_id, diagnostics)),
1631                    Ok(ix) => self.diagnostics[ix].1 = diagnostics,
1632                };
1633            }
1634            self.diagnostics_timestamp = lamport_timestamp;
1635            self.diagnostics_update_count += 1;
1636            self.text.lamport_clock.observe(lamport_timestamp);
1637            cx.notify();
1638            cx.emit(Event::DiagnosticsUpdated);
1639        }
1640    }
1641
1642    fn send_operation(&mut self, operation: Operation, cx: &mut ModelContext<Self>) {
1643        cx.emit(Event::Operation(operation));
1644    }
1645
1646    pub fn remove_peer(&mut self, replica_id: ReplicaId, cx: &mut ModelContext<Self>) {
1647        self.remote_selections.remove(&replica_id);
1648        cx.notify();
1649    }
1650
1651    pub fn undo(&mut self, cx: &mut ModelContext<Self>) -> Option<TransactionId> {
1652        let was_dirty = self.is_dirty();
1653        let old_version = self.version.clone();
1654
1655        if let Some((transaction_id, operation)) = self.text.undo() {
1656            self.send_operation(Operation::Buffer(operation), cx);
1657            self.did_edit(&old_version, was_dirty, cx);
1658            Some(transaction_id)
1659        } else {
1660            None
1661        }
1662    }
1663
1664    pub fn undo_to_transaction(
1665        &mut self,
1666        transaction_id: TransactionId,
1667        cx: &mut ModelContext<Self>,
1668    ) -> bool {
1669        let was_dirty = self.is_dirty();
1670        let old_version = self.version.clone();
1671
1672        let operations = self.text.undo_to_transaction(transaction_id);
1673        let undone = !operations.is_empty();
1674        for operation in operations {
1675            self.send_operation(Operation::Buffer(operation), cx);
1676        }
1677        if undone {
1678            self.did_edit(&old_version, was_dirty, cx)
1679        }
1680        undone
1681    }
1682
1683    pub fn redo(&mut self, cx: &mut ModelContext<Self>) -> Option<TransactionId> {
1684        let was_dirty = self.is_dirty();
1685        let old_version = self.version.clone();
1686
1687        if let Some((transaction_id, operation)) = self.text.redo() {
1688            self.send_operation(Operation::Buffer(operation), cx);
1689            self.did_edit(&old_version, was_dirty, cx);
1690            Some(transaction_id)
1691        } else {
1692            None
1693        }
1694    }
1695
1696    pub fn redo_to_transaction(
1697        &mut self,
1698        transaction_id: TransactionId,
1699        cx: &mut ModelContext<Self>,
1700    ) -> bool {
1701        let was_dirty = self.is_dirty();
1702        let old_version = self.version.clone();
1703
1704        let operations = self.text.redo_to_transaction(transaction_id);
1705        let redone = !operations.is_empty();
1706        for operation in operations {
1707            self.send_operation(Operation::Buffer(operation), cx);
1708        }
1709        if redone {
1710            self.did_edit(&old_version, was_dirty, cx)
1711        }
1712        redone
1713    }
1714
1715    pub fn set_completion_triggers(&mut self, triggers: Vec<String>, cx: &mut ModelContext<Self>) {
1716        self.completion_triggers = triggers.clone();
1717        self.completion_triggers_timestamp = self.text.lamport_clock.tick();
1718        self.send_operation(
1719            Operation::UpdateCompletionTriggers {
1720                triggers,
1721                lamport_timestamp: self.completion_triggers_timestamp,
1722            },
1723            cx,
1724        );
1725        cx.notify();
1726    }
1727
1728    pub fn completion_triggers(&self) -> &[String] {
1729        &self.completion_triggers
1730    }
1731}
1732
1733#[cfg(any(test, feature = "test-support"))]
1734impl Buffer {
1735    pub fn edit_via_marked_text(
1736        &mut self,
1737        marked_string: &str,
1738        autoindent_mode: Option<AutoindentMode>,
1739        cx: &mut ModelContext<Self>,
1740    ) {
1741        let edits = self.edits_for_marked_text(marked_string);
1742        self.edit(edits, autoindent_mode, cx);
1743    }
1744
1745    pub fn set_group_interval(&mut self, group_interval: Duration) {
1746        self.text.set_group_interval(group_interval);
1747    }
1748
1749    pub fn randomly_edit<T>(
1750        &mut self,
1751        rng: &mut T,
1752        old_range_count: usize,
1753        cx: &mut ModelContext<Self>,
1754    ) where
1755        T: rand::Rng,
1756    {
1757        let mut edits: Vec<(Range<usize>, String)> = Vec::new();
1758        let mut last_end = None;
1759        for _ in 0..old_range_count {
1760            if last_end.map_or(false, |last_end| last_end >= self.len()) {
1761                break;
1762            }
1763
1764            let new_start = last_end.map_or(0, |last_end| last_end + 1);
1765            let mut range = self.random_byte_range(new_start, rng);
1766            if rng.gen_bool(0.2) {
1767                mem::swap(&mut range.start, &mut range.end);
1768            }
1769            last_end = Some(range.end);
1770
1771            let new_text_len = rng.gen_range(0..10);
1772            let new_text: String = RandomCharIter::new(&mut *rng).take(new_text_len).collect();
1773
1774            edits.push((range, new_text));
1775        }
1776        log::info!("mutating buffer {} with {:?}", self.replica_id(), edits);
1777        self.edit(edits, None, cx);
1778    }
1779
1780    pub fn randomly_undo_redo(&mut self, rng: &mut impl rand::Rng, cx: &mut ModelContext<Self>) {
1781        let was_dirty = self.is_dirty();
1782        let old_version = self.version.clone();
1783
1784        let ops = self.text.randomly_undo_redo(rng);
1785        if !ops.is_empty() {
1786            for op in ops {
1787                self.send_operation(Operation::Buffer(op), cx);
1788                self.did_edit(&old_version, was_dirty, cx);
1789            }
1790        }
1791    }
1792}
1793
1794impl Entity for Buffer {
1795    type Event = Event;
1796}
1797
1798impl Deref for Buffer {
1799    type Target = TextBuffer;
1800
1801    fn deref(&self) -> &Self::Target {
1802        &self.text
1803    }
1804}
1805
1806impl BufferSnapshot {
1807    pub fn indent_size_for_line(&self, row: u32) -> IndentSize {
1808        indent_size_for_line(self, row)
1809    }
1810
1811    pub fn language_indent_size_at<T: ToOffset>(&self, position: T, cx: &AppContext) -> IndentSize {
1812        let settings = language_settings(self.language_at(position), self.file(), cx);
1813        if settings.hard_tabs {
1814            IndentSize::tab()
1815        } else {
1816            IndentSize::spaces(settings.tab_size.get())
1817        }
1818    }
1819
1820    pub fn suggested_indents(
1821        &self,
1822        rows: impl Iterator<Item = u32>,
1823        single_indent_size: IndentSize,
1824    ) -> BTreeMap<u32, IndentSize> {
1825        let mut result = BTreeMap::new();
1826
1827        for row_range in contiguous_ranges(rows, 10) {
1828            let suggestions = match self.suggest_autoindents(row_range.clone()) {
1829                Some(suggestions) => suggestions,
1830                _ => break,
1831            };
1832
1833            for (row, suggestion) in row_range.zip(suggestions) {
1834                let indent_size = if let Some(suggestion) = suggestion {
1835                    result
1836                        .get(&suggestion.basis_row)
1837                        .copied()
1838                        .unwrap_or_else(|| self.indent_size_for_line(suggestion.basis_row))
1839                        .with_delta(suggestion.delta, single_indent_size)
1840                } else {
1841                    self.indent_size_for_line(row)
1842                };
1843
1844                result.insert(row, indent_size);
1845            }
1846        }
1847
1848        result
1849    }
1850
1851    fn suggest_autoindents(
1852        &self,
1853        row_range: Range<u32>,
1854    ) -> Option<impl Iterator<Item = Option<IndentSuggestion>> + '_> {
1855        let config = &self.language.as_ref()?.config;
1856        let prev_non_blank_row = self.prev_non_blank_row(row_range.start);
1857
1858        // Find the suggested indentation ranges based on the syntax tree.
1859        let start = Point::new(prev_non_blank_row.unwrap_or(row_range.start), 0);
1860        let end = Point::new(row_range.end, 0);
1861        let range = (start..end).to_offset(&self.text);
1862        let mut matches = self.syntax.matches(range.clone(), &self.text, |grammar| {
1863            Some(&grammar.indents_config.as_ref()?.query)
1864        });
1865        let indent_configs = matches
1866            .grammars()
1867            .iter()
1868            .map(|grammar| grammar.indents_config.as_ref().unwrap())
1869            .collect::<Vec<_>>();
1870
1871        let mut indent_ranges = Vec::<Range<Point>>::new();
1872        let mut outdent_positions = Vec::<Point>::new();
1873        while let Some(mat) = matches.peek() {
1874            let mut start: Option<Point> = None;
1875            let mut end: Option<Point> = None;
1876
1877            let config = &indent_configs[mat.grammar_index];
1878            for capture in mat.captures {
1879                if capture.index == config.indent_capture_ix {
1880                    start.get_or_insert(Point::from_ts_point(capture.node.start_position()));
1881                    end.get_or_insert(Point::from_ts_point(capture.node.end_position()));
1882                } else if Some(capture.index) == config.start_capture_ix {
1883                    start = Some(Point::from_ts_point(capture.node.end_position()));
1884                } else if Some(capture.index) == config.end_capture_ix {
1885                    end = Some(Point::from_ts_point(capture.node.start_position()));
1886                } else if Some(capture.index) == config.outdent_capture_ix {
1887                    outdent_positions.push(Point::from_ts_point(capture.node.start_position()));
1888                }
1889            }
1890
1891            matches.advance();
1892            if let Some((start, end)) = start.zip(end) {
1893                if start.row == end.row {
1894                    continue;
1895                }
1896
1897                let range = start..end;
1898                match indent_ranges.binary_search_by_key(&range.start, |r| r.start) {
1899                    Err(ix) => indent_ranges.insert(ix, range),
1900                    Ok(ix) => {
1901                        let prev_range = &mut indent_ranges[ix];
1902                        prev_range.end = prev_range.end.max(range.end);
1903                    }
1904                }
1905            }
1906        }
1907
1908        let mut error_ranges = Vec::<Range<Point>>::new();
1909        let mut matches = self.syntax.matches(range.clone(), &self.text, |grammar| {
1910            Some(&grammar.error_query)
1911        });
1912        while let Some(mat) = matches.peek() {
1913            let node = mat.captures[0].node;
1914            let start = Point::from_ts_point(node.start_position());
1915            let end = Point::from_ts_point(node.end_position());
1916            let range = start..end;
1917            let ix = match error_ranges.binary_search_by_key(&range.start, |r| r.start) {
1918                Ok(ix) | Err(ix) => ix,
1919            };
1920            let mut end_ix = ix;
1921            while let Some(existing_range) = error_ranges.get(end_ix) {
1922                if existing_range.end < end {
1923                    end_ix += 1;
1924                } else {
1925                    break;
1926                }
1927            }
1928            error_ranges.splice(ix..end_ix, [range]);
1929            matches.advance();
1930        }
1931
1932        outdent_positions.sort();
1933        for outdent_position in outdent_positions {
1934            // find the innermost indent range containing this outdent_position
1935            // set its end to the outdent position
1936            if let Some(range_to_truncate) = indent_ranges
1937                .iter_mut()
1938                .filter(|indent_range| indent_range.contains(&outdent_position))
1939                .last()
1940            {
1941                range_to_truncate.end = outdent_position;
1942            }
1943        }
1944
1945        // Find the suggested indentation increases and decreased based on regexes.
1946        let mut indent_change_rows = Vec::<(u32, Ordering)>::new();
1947        self.for_each_line(
1948            Point::new(prev_non_blank_row.unwrap_or(row_range.start), 0)
1949                ..Point::new(row_range.end, 0),
1950            |row, line| {
1951                if config
1952                    .decrease_indent_pattern
1953                    .as_ref()
1954                    .map_or(false, |regex| regex.is_match(line))
1955                {
1956                    indent_change_rows.push((row, Ordering::Less));
1957                }
1958                if config
1959                    .increase_indent_pattern
1960                    .as_ref()
1961                    .map_or(false, |regex| regex.is_match(line))
1962                {
1963                    indent_change_rows.push((row + 1, Ordering::Greater));
1964                }
1965            },
1966        );
1967
1968        let mut indent_changes = indent_change_rows.into_iter().peekable();
1969        let mut prev_row = if config.auto_indent_using_last_non_empty_line {
1970            prev_non_blank_row.unwrap_or(0)
1971        } else {
1972            row_range.start.saturating_sub(1)
1973        };
1974        let mut prev_row_start = Point::new(prev_row, self.indent_size_for_line(prev_row).len);
1975        Some(row_range.map(move |row| {
1976            let row_start = Point::new(row, self.indent_size_for_line(row).len);
1977
1978            let mut indent_from_prev_row = false;
1979            let mut outdent_from_prev_row = false;
1980            let mut outdent_to_row = u32::MAX;
1981
1982            while let Some((indent_row, delta)) = indent_changes.peek() {
1983                match indent_row.cmp(&row) {
1984                    Ordering::Equal => match delta {
1985                        Ordering::Less => outdent_from_prev_row = true,
1986                        Ordering::Greater => indent_from_prev_row = true,
1987                        _ => {}
1988                    },
1989
1990                    Ordering::Greater => break,
1991                    Ordering::Less => {}
1992                }
1993
1994                indent_changes.next();
1995            }
1996
1997            for range in &indent_ranges {
1998                if range.start.row >= row {
1999                    break;
2000                }
2001                if range.start.row == prev_row && range.end > row_start {
2002                    indent_from_prev_row = true;
2003                }
2004                if range.end > prev_row_start && range.end <= row_start {
2005                    outdent_to_row = outdent_to_row.min(range.start.row);
2006                }
2007            }
2008
2009            let within_error = error_ranges
2010                .iter()
2011                .any(|e| e.start.row < row && e.end > row_start);
2012
2013            let suggestion = if outdent_to_row == prev_row
2014                || (outdent_from_prev_row && indent_from_prev_row)
2015            {
2016                Some(IndentSuggestion {
2017                    basis_row: prev_row,
2018                    delta: Ordering::Equal,
2019                    within_error,
2020                })
2021            } else if indent_from_prev_row {
2022                Some(IndentSuggestion {
2023                    basis_row: prev_row,
2024                    delta: Ordering::Greater,
2025                    within_error,
2026                })
2027            } else if outdent_to_row < prev_row {
2028                Some(IndentSuggestion {
2029                    basis_row: outdent_to_row,
2030                    delta: Ordering::Equal,
2031                    within_error,
2032                })
2033            } else if outdent_from_prev_row {
2034                Some(IndentSuggestion {
2035                    basis_row: prev_row,
2036                    delta: Ordering::Less,
2037                    within_error,
2038                })
2039            } else if config.auto_indent_using_last_non_empty_line || !self.is_line_blank(prev_row)
2040            {
2041                Some(IndentSuggestion {
2042                    basis_row: prev_row,
2043                    delta: Ordering::Equal,
2044                    within_error,
2045                })
2046            } else {
2047                None
2048            };
2049
2050            prev_row = row;
2051            prev_row_start = row_start;
2052            suggestion
2053        }))
2054    }
2055
2056    fn prev_non_blank_row(&self, mut row: u32) -> Option<u32> {
2057        while row > 0 {
2058            row -= 1;
2059            if !self.is_line_blank(row) {
2060                return Some(row);
2061            }
2062        }
2063        None
2064    }
2065
2066    pub fn chunks<T: ToOffset>(&self, range: Range<T>, language_aware: bool) -> BufferChunks {
2067        let range = range.start.to_offset(self)..range.end.to_offset(self);
2068
2069        let mut syntax = None;
2070        let mut diagnostic_endpoints = Vec::new();
2071        if language_aware {
2072            let captures = self.syntax.captures(range.clone(), &self.text, |grammar| {
2073                grammar.highlights_query.as_ref()
2074            });
2075            let highlight_maps = captures
2076                .grammars()
2077                .into_iter()
2078                .map(|grammar| grammar.highlight_map())
2079                .collect();
2080            syntax = Some((captures, highlight_maps));
2081            for entry in self.diagnostics_in_range::<_, usize>(range.clone(), false) {
2082                diagnostic_endpoints.push(DiagnosticEndpoint {
2083                    offset: entry.range.start,
2084                    is_start: true,
2085                    severity: entry.diagnostic.severity,
2086                    is_unnecessary: entry.diagnostic.is_unnecessary,
2087                });
2088                diagnostic_endpoints.push(DiagnosticEndpoint {
2089                    offset: entry.range.end,
2090                    is_start: false,
2091                    severity: entry.diagnostic.severity,
2092                    is_unnecessary: entry.diagnostic.is_unnecessary,
2093                });
2094            }
2095            diagnostic_endpoints
2096                .sort_unstable_by_key(|endpoint| (endpoint.offset, !endpoint.is_start));
2097        }
2098
2099        BufferChunks::new(self.text.as_rope(), range, syntax, diagnostic_endpoints)
2100    }
2101
2102    pub fn for_each_line(&self, range: Range<Point>, mut callback: impl FnMut(u32, &str)) {
2103        let mut line = String::new();
2104        let mut row = range.start.row;
2105        for chunk in self
2106            .as_rope()
2107            .chunks_in_range(range.to_offset(self))
2108            .chain(["\n"])
2109        {
2110            for (newline_ix, text) in chunk.split('\n').enumerate() {
2111                if newline_ix > 0 {
2112                    callback(row, &line);
2113                    row += 1;
2114                    line.clear();
2115                }
2116                line.push_str(text);
2117            }
2118        }
2119    }
2120
2121    pub fn syntax_layers(&self) -> impl Iterator<Item = SyntaxLayerInfo> + '_ {
2122        self.syntax.layers_for_range(0..self.len(), &self.text)
2123    }
2124
2125    pub fn syntax_layer_at<D: ToOffset>(&self, position: D) -> Option<SyntaxLayerInfo> {
2126        let offset = position.to_offset(self);
2127        self.syntax
2128            .layers_for_range(offset..offset, &self.text)
2129            .filter(|l| l.node().end_byte() > offset)
2130            .last()
2131    }
2132
2133    pub fn language_at<D: ToOffset>(&self, position: D) -> Option<&Arc<Language>> {
2134        self.syntax_layer_at(position)
2135            .map(|info| info.language)
2136            .or(self.language.as_ref())
2137    }
2138
2139    pub fn settings_at<'a, D: ToOffset>(
2140        &self,
2141        position: D,
2142        cx: &'a AppContext,
2143    ) -> &'a LanguageSettings {
2144        language_settings(self.language_at(position), self.file.as_ref(), cx)
2145    }
2146
2147    pub fn language_scope_at<D: ToOffset>(&self, position: D) -> Option<LanguageScope> {
2148        let offset = position.to_offset(self);
2149        let mut range = 0..self.len();
2150        let mut scope = self.language.clone().map(|language| LanguageScope {
2151            language,
2152            override_id: None,
2153        });
2154
2155        // Use the layer that has the smallest node intersecting the given point.
2156        for layer in self.syntax.layers_for_range(offset..offset, &self.text) {
2157            let mut cursor = layer.node().walk();
2158            while cursor.goto_first_child_for_byte(offset).is_some() {}
2159            let node_range = cursor.node().byte_range();
2160            if node_range.to_inclusive().contains(&offset) && node_range.len() < range.len() {
2161                range = node_range;
2162                scope = Some(LanguageScope {
2163                    language: layer.language.clone(),
2164                    override_id: layer.override_id(offset, &self.text),
2165                });
2166            }
2167        }
2168
2169        scope
2170    }
2171
2172    pub fn surrounding_word<T: ToOffset>(&self, start: T) -> (Range<usize>, Option<CharKind>) {
2173        let mut start = start.to_offset(self);
2174        let mut end = start;
2175        let mut next_chars = self.chars_at(start).peekable();
2176        let mut prev_chars = self.reversed_chars_at(start).peekable();
2177
2178        let scope = self.language_scope_at(start);
2179        let kind = |c| char_kind(&scope, c);
2180        let word_kind = cmp::max(
2181            prev_chars.peek().copied().map(kind),
2182            next_chars.peek().copied().map(kind),
2183        );
2184
2185        for ch in prev_chars {
2186            if Some(kind(ch)) == word_kind && ch != '\n' {
2187                start -= ch.len_utf8();
2188            } else {
2189                break;
2190            }
2191        }
2192
2193        for ch in next_chars {
2194            if Some(kind(ch)) == word_kind && ch != '\n' {
2195                end += ch.len_utf8();
2196            } else {
2197                break;
2198            }
2199        }
2200
2201        (start..end, word_kind)
2202    }
2203
2204    pub fn range_for_syntax_ancestor<T: ToOffset>(&self, range: Range<T>) -> Option<Range<usize>> {
2205        let range = range.start.to_offset(self)..range.end.to_offset(self);
2206        let mut result: Option<Range<usize>> = None;
2207        'outer: for layer in self.syntax.layers_for_range(range.clone(), &self.text) {
2208            let mut cursor = layer.node().walk();
2209
2210            // Descend to the first leaf that touches the start of the range,
2211            // and if the range is non-empty, extends beyond the start.
2212            while cursor.goto_first_child_for_byte(range.start).is_some() {
2213                if !range.is_empty() && cursor.node().end_byte() == range.start {
2214                    cursor.goto_next_sibling();
2215                }
2216            }
2217
2218            // Ascend to the smallest ancestor that strictly contains the range.
2219            loop {
2220                let node_range = cursor.node().byte_range();
2221                if node_range.start <= range.start
2222                    && node_range.end >= range.end
2223                    && node_range.len() > range.len()
2224                {
2225                    break;
2226                }
2227                if !cursor.goto_parent() {
2228                    continue 'outer;
2229                }
2230            }
2231
2232            let left_node = cursor.node();
2233            let mut layer_result = left_node.byte_range();
2234
2235            // For an empty range, try to find another node immediately to the right of the range.
2236            if left_node.end_byte() == range.start {
2237                let mut right_node = None;
2238                while !cursor.goto_next_sibling() {
2239                    if !cursor.goto_parent() {
2240                        break;
2241                    }
2242                }
2243
2244                while cursor.node().start_byte() == range.start {
2245                    right_node = Some(cursor.node());
2246                    if !cursor.goto_first_child() {
2247                        break;
2248                    }
2249                }
2250
2251                // If there is a candidate node on both sides of the (empty) range, then
2252                // decide between the two by favoring a named node over an anonymous token.
2253                // If both nodes are the same in that regard, favor the right one.
2254                if let Some(right_node) = right_node {
2255                    if right_node.is_named() || !left_node.is_named() {
2256                        layer_result = right_node.byte_range();
2257                    }
2258                }
2259            }
2260
2261            if let Some(previous_result) = &result {
2262                if previous_result.len() < layer_result.len() {
2263                    continue;
2264                }
2265            }
2266            result = Some(layer_result);
2267        }
2268
2269        result
2270    }
2271
2272    pub fn outline(&self, theme: Option<&SyntaxTheme>) -> Option<Outline<Anchor>> {
2273        self.outline_items_containing(0..self.len(), true, theme)
2274            .map(Outline::new)
2275    }
2276
2277    pub fn symbols_containing<T: ToOffset>(
2278        &self,
2279        position: T,
2280        theme: Option<&SyntaxTheme>,
2281    ) -> Option<Vec<OutlineItem<Anchor>>> {
2282        let position = position.to_offset(self);
2283        let mut items = self.outline_items_containing(
2284            position.saturating_sub(1)..self.len().min(position + 1),
2285            false,
2286            theme,
2287        )?;
2288        let mut prev_depth = None;
2289        items.retain(|item| {
2290            let result = prev_depth.map_or(true, |prev_depth| item.depth > prev_depth);
2291            prev_depth = Some(item.depth);
2292            result
2293        });
2294        Some(items)
2295    }
2296
2297    fn outline_items_containing(
2298        &self,
2299        range: Range<usize>,
2300        include_extra_context: bool,
2301        theme: Option<&SyntaxTheme>,
2302    ) -> Option<Vec<OutlineItem<Anchor>>> {
2303        let mut matches = self.syntax.matches(range.clone(), &self.text, |grammar| {
2304            grammar.outline_config.as_ref().map(|c| &c.query)
2305        });
2306        let configs = matches
2307            .grammars()
2308            .iter()
2309            .map(|g| g.outline_config.as_ref().unwrap())
2310            .collect::<Vec<_>>();
2311
2312        let mut stack = Vec::<Range<usize>>::new();
2313        let mut items = Vec::new();
2314        while let Some(mat) = matches.peek() {
2315            let config = &configs[mat.grammar_index];
2316            let item_node = mat.captures.iter().find_map(|cap| {
2317                if cap.index == config.item_capture_ix {
2318                    Some(cap.node)
2319                } else {
2320                    None
2321                }
2322            })?;
2323
2324            let item_range = item_node.byte_range();
2325            if item_range.end < range.start || item_range.start > range.end {
2326                matches.advance();
2327                continue;
2328            }
2329
2330            let mut buffer_ranges = Vec::new();
2331            for capture in mat.captures {
2332                let node_is_name;
2333                if capture.index == config.name_capture_ix {
2334                    node_is_name = true;
2335                } else if Some(capture.index) == config.context_capture_ix
2336                    || (Some(capture.index) == config.extra_context_capture_ix
2337                        && include_extra_context)
2338                {
2339                    node_is_name = false;
2340                } else {
2341                    continue;
2342                }
2343
2344                let mut range = capture.node.start_byte()..capture.node.end_byte();
2345                let start = capture.node.start_position();
2346                if capture.node.end_position().row > start.row {
2347                    range.end =
2348                        range.start + self.line_len(start.row as u32) as usize - start.column;
2349                }
2350
2351                buffer_ranges.push((range, node_is_name));
2352            }
2353
2354            if buffer_ranges.is_empty() {
2355                continue;
2356            }
2357
2358            let mut text = String::new();
2359            let mut highlight_ranges = Vec::new();
2360            let mut name_ranges = Vec::new();
2361            let mut chunks = self.chunks(
2362                buffer_ranges.first().unwrap().0.start..buffer_ranges.last().unwrap().0.end,
2363                true,
2364            );
2365            let mut last_buffer_range_end = 0;
2366            for (buffer_range, is_name) in buffer_ranges {
2367                if !text.is_empty() && buffer_range.start > last_buffer_range_end {
2368                    text.push(' ');
2369                }
2370                last_buffer_range_end = buffer_range.end;
2371                if is_name {
2372                    let mut start = text.len();
2373                    let end = start + buffer_range.len();
2374
2375                    // When multiple names are captured, then the matcheable text
2376                    // includes the whitespace in between the names.
2377                    if !name_ranges.is_empty() {
2378                        start -= 1;
2379                    }
2380
2381                    name_ranges.push(start..end);
2382                }
2383
2384                let mut offset = buffer_range.start;
2385                chunks.seek(offset);
2386                for mut chunk in chunks.by_ref() {
2387                    if chunk.text.len() > buffer_range.end - offset {
2388                        chunk.text = &chunk.text[0..(buffer_range.end - offset)];
2389                        offset = buffer_range.end;
2390                    } else {
2391                        offset += chunk.text.len();
2392                    }
2393                    let style = chunk
2394                        .syntax_highlight_id
2395                        .zip(theme)
2396                        .and_then(|(highlight, theme)| highlight.style(theme));
2397                    if let Some(style) = style {
2398                        let start = text.len();
2399                        let end = start + chunk.text.len();
2400                        highlight_ranges.push((start..end, style));
2401                    }
2402                    text.push_str(chunk.text);
2403                    if offset >= buffer_range.end {
2404                        break;
2405                    }
2406                }
2407            }
2408
2409            matches.advance();
2410            while stack.last().map_or(false, |prev_range| {
2411                prev_range.start > item_range.start || prev_range.end < item_range.end
2412            }) {
2413                stack.pop();
2414            }
2415            stack.push(item_range.clone());
2416
2417            items.push(OutlineItem {
2418                depth: stack.len() - 1,
2419                range: self.anchor_after(item_range.start)..self.anchor_before(item_range.end),
2420                text,
2421                highlight_ranges,
2422                name_ranges,
2423            })
2424        }
2425        Some(items)
2426    }
2427
2428    /// Returns bracket range pairs overlapping or adjacent to `range`
2429    pub fn bracket_ranges<'a, T: ToOffset>(
2430        &'a self,
2431        range: Range<T>,
2432    ) -> impl Iterator<Item = (Range<usize>, Range<usize>)> + 'a {
2433        // Find bracket pairs that *inclusively* contain the given range.
2434        let range = range.start.to_offset(self).saturating_sub(1)
2435            ..self.len().min(range.end.to_offset(self) + 1);
2436
2437        let mut matches = self.syntax.matches(range.clone(), &self.text, |grammar| {
2438            grammar.brackets_config.as_ref().map(|c| &c.query)
2439        });
2440        let configs = matches
2441            .grammars()
2442            .iter()
2443            .map(|grammar| grammar.brackets_config.as_ref().unwrap())
2444            .collect::<Vec<_>>();
2445
2446        iter::from_fn(move || {
2447            while let Some(mat) = matches.peek() {
2448                let mut open = None;
2449                let mut close = None;
2450                let config = &configs[mat.grammar_index];
2451                for capture in mat.captures {
2452                    if capture.index == config.open_capture_ix {
2453                        open = Some(capture.node.byte_range());
2454                    } else if capture.index == config.close_capture_ix {
2455                        close = Some(capture.node.byte_range());
2456                    }
2457                }
2458
2459                matches.advance();
2460
2461                let Some((open, close)) = open.zip(close) else { continue };
2462
2463                let bracket_range = open.start..=close.end;
2464                if !bracket_range.overlaps(&range) {
2465                    continue;
2466                }
2467
2468                return Some((open, close));
2469            }
2470            None
2471        })
2472    }
2473
2474    #[allow(clippy::type_complexity)]
2475    pub fn remote_selections_in_range(
2476        &self,
2477        range: Range<Anchor>,
2478    ) -> impl Iterator<
2479        Item = (
2480            ReplicaId,
2481            bool,
2482            CursorShape,
2483            impl Iterator<Item = &Selection<Anchor>> + '_,
2484        ),
2485    > + '_ {
2486        self.remote_selections
2487            .iter()
2488            .filter(|(replica_id, set)| {
2489                **replica_id != self.text.replica_id() && !set.selections.is_empty()
2490            })
2491            .map(move |(replica_id, set)| {
2492                let start_ix = match set.selections.binary_search_by(|probe| {
2493                    probe.end.cmp(&range.start, self).then(Ordering::Greater)
2494                }) {
2495                    Ok(ix) | Err(ix) => ix,
2496                };
2497                let end_ix = match set.selections.binary_search_by(|probe| {
2498                    probe.start.cmp(&range.end, self).then(Ordering::Less)
2499                }) {
2500                    Ok(ix) | Err(ix) => ix,
2501                };
2502
2503                (
2504                    *replica_id,
2505                    set.line_mode,
2506                    set.cursor_shape,
2507                    set.selections[start_ix..end_ix].iter(),
2508                )
2509            })
2510    }
2511
2512    pub fn git_diff_hunks_in_row_range<'a>(
2513        &'a self,
2514        range: Range<u32>,
2515    ) -> impl 'a + Iterator<Item = git::diff::DiffHunk<u32>> {
2516        self.git_diff.hunks_in_row_range(range, self)
2517    }
2518
2519    pub fn git_diff_hunks_intersecting_range<'a>(
2520        &'a self,
2521        range: Range<Anchor>,
2522    ) -> impl 'a + Iterator<Item = git::diff::DiffHunk<u32>> {
2523        self.git_diff.hunks_intersecting_range(range, self)
2524    }
2525
2526    pub fn git_diff_hunks_intersecting_range_rev<'a>(
2527        &'a self,
2528        range: Range<Anchor>,
2529    ) -> impl 'a + Iterator<Item = git::diff::DiffHunk<u32>> {
2530        self.git_diff.hunks_intersecting_range_rev(range, self)
2531    }
2532
2533    pub fn diagnostics_in_range<'a, T, O>(
2534        &'a self,
2535        search_range: Range<T>,
2536        reversed: bool,
2537    ) -> impl 'a + Iterator<Item = DiagnosticEntry<O>>
2538    where
2539        T: 'a + Clone + ToOffset,
2540        O: 'a + FromAnchor + Ord,
2541    {
2542        let mut iterators: Vec<_> = self
2543            .diagnostics
2544            .iter()
2545            .map(|(_, collection)| {
2546                collection
2547                    .range::<T, O>(search_range.clone(), self, true, reversed)
2548                    .peekable()
2549            })
2550            .collect();
2551
2552        std::iter::from_fn(move || {
2553            let (next_ix, _) = iterators
2554                .iter_mut()
2555                .enumerate()
2556                .flat_map(|(ix, iter)| Some((ix, iter.peek()?)))
2557                .min_by(|(_, a), (_, b)| a.range.start.cmp(&b.range.start))?;
2558            iterators[next_ix].next()
2559        })
2560    }
2561
2562    pub fn diagnostic_groups(
2563        &self,
2564        language_server_id: Option<LanguageServerId>,
2565    ) -> Vec<(LanguageServerId, DiagnosticGroup<Anchor>)> {
2566        let mut groups = Vec::new();
2567
2568        if let Some(language_server_id) = language_server_id {
2569            if let Ok(ix) = self
2570                .diagnostics
2571                .binary_search_by_key(&language_server_id, |e| e.0)
2572            {
2573                self.diagnostics[ix]
2574                    .1
2575                    .groups(language_server_id, &mut groups, self);
2576            }
2577        } else {
2578            for (language_server_id, diagnostics) in self.diagnostics.iter() {
2579                diagnostics.groups(*language_server_id, &mut groups, self);
2580            }
2581        }
2582
2583        groups.sort_by(|(id_a, group_a), (id_b, group_b)| {
2584            let a_start = &group_a.entries[group_a.primary_ix].range.start;
2585            let b_start = &group_b.entries[group_b.primary_ix].range.start;
2586            a_start.cmp(b_start, self).then_with(|| id_a.cmp(&id_b))
2587        });
2588
2589        groups
2590    }
2591
2592    pub fn diagnostic_group<'a, O>(
2593        &'a self,
2594        group_id: usize,
2595    ) -> impl 'a + Iterator<Item = DiagnosticEntry<O>>
2596    where
2597        O: 'a + FromAnchor,
2598    {
2599        self.diagnostics
2600            .iter()
2601            .flat_map(move |(_, set)| set.group(group_id, self))
2602    }
2603
2604    pub fn diagnostics_update_count(&self) -> usize {
2605        self.diagnostics_update_count
2606    }
2607
2608    pub fn parse_count(&self) -> usize {
2609        self.parse_count
2610    }
2611
2612    pub fn selections_update_count(&self) -> usize {
2613        self.selections_update_count
2614    }
2615
2616    pub fn file(&self) -> Option<&Arc<dyn File>> {
2617        self.file.as_ref()
2618    }
2619
2620    pub fn resolve_file_path(&self, cx: &AppContext, include_root: bool) -> Option<PathBuf> {
2621        if let Some(file) = self.file() {
2622            if file.path().file_name().is_none() || include_root {
2623                Some(file.full_path(cx))
2624            } else {
2625                Some(file.path().to_path_buf())
2626            }
2627        } else {
2628            None
2629        }
2630    }
2631
2632    pub fn file_update_count(&self) -> usize {
2633        self.file_update_count
2634    }
2635
2636    pub fn git_diff_update_count(&self) -> usize {
2637        self.git_diff_update_count
2638    }
2639}
2640
2641fn indent_size_for_line(text: &text::BufferSnapshot, row: u32) -> IndentSize {
2642    indent_size_for_text(text.chars_at(Point::new(row, 0)))
2643}
2644
2645pub fn indent_size_for_text(text: impl Iterator<Item = char>) -> IndentSize {
2646    let mut result = IndentSize::spaces(0);
2647    for c in text {
2648        let kind = match c {
2649            ' ' => IndentKind::Space,
2650            '\t' => IndentKind::Tab,
2651            _ => break,
2652        };
2653        if result.len == 0 {
2654            result.kind = kind;
2655        }
2656        result.len += 1;
2657    }
2658    result
2659}
2660
2661impl Clone for BufferSnapshot {
2662    fn clone(&self) -> Self {
2663        Self {
2664            text: self.text.clone(),
2665            git_diff: self.git_diff.clone(),
2666            syntax: self.syntax.clone(),
2667            file: self.file.clone(),
2668            remote_selections: self.remote_selections.clone(),
2669            diagnostics: self.diagnostics.clone(),
2670            selections_update_count: self.selections_update_count,
2671            diagnostics_update_count: self.diagnostics_update_count,
2672            file_update_count: self.file_update_count,
2673            git_diff_update_count: self.git_diff_update_count,
2674            language: self.language.clone(),
2675            parse_count: self.parse_count,
2676        }
2677    }
2678}
2679
2680impl Deref for BufferSnapshot {
2681    type Target = text::BufferSnapshot;
2682
2683    fn deref(&self) -> &Self::Target {
2684        &self.text
2685    }
2686}
2687
2688unsafe impl<'a> Send for BufferChunks<'a> {}
2689
2690impl<'a> BufferChunks<'a> {
2691    pub(crate) fn new(
2692        text: &'a Rope,
2693        range: Range<usize>,
2694        syntax: Option<(SyntaxMapCaptures<'a>, Vec<HighlightMap>)>,
2695        diagnostic_endpoints: Vec<DiagnosticEndpoint>,
2696    ) -> Self {
2697        let mut highlights = None;
2698        if let Some((captures, highlight_maps)) = syntax {
2699            highlights = Some(BufferChunkHighlights {
2700                captures,
2701                next_capture: None,
2702                stack: Default::default(),
2703                highlight_maps,
2704            })
2705        }
2706
2707        let diagnostic_endpoints = diagnostic_endpoints.into_iter().peekable();
2708        let chunks = text.chunks_in_range(range.clone());
2709
2710        BufferChunks {
2711            range,
2712            chunks,
2713            diagnostic_endpoints,
2714            error_depth: 0,
2715            warning_depth: 0,
2716            information_depth: 0,
2717            hint_depth: 0,
2718            unnecessary_depth: 0,
2719            highlights,
2720        }
2721    }
2722
2723    pub fn seek(&mut self, offset: usize) {
2724        self.range.start = offset;
2725        self.chunks.seek(self.range.start);
2726        if let Some(highlights) = self.highlights.as_mut() {
2727            highlights
2728                .stack
2729                .retain(|(end_offset, _)| *end_offset > offset);
2730            if let Some(capture) = &highlights.next_capture {
2731                if offset >= capture.node.start_byte() {
2732                    let next_capture_end = capture.node.end_byte();
2733                    if offset < next_capture_end {
2734                        highlights.stack.push((
2735                            next_capture_end,
2736                            highlights.highlight_maps[capture.grammar_index].get(capture.index),
2737                        ));
2738                    }
2739                    highlights.next_capture.take();
2740                }
2741            }
2742            highlights.captures.set_byte_range(self.range.clone());
2743        }
2744    }
2745
2746    pub fn offset(&self) -> usize {
2747        self.range.start
2748    }
2749
2750    fn update_diagnostic_depths(&mut self, endpoint: DiagnosticEndpoint) {
2751        let depth = match endpoint.severity {
2752            DiagnosticSeverity::ERROR => &mut self.error_depth,
2753            DiagnosticSeverity::WARNING => &mut self.warning_depth,
2754            DiagnosticSeverity::INFORMATION => &mut self.information_depth,
2755            DiagnosticSeverity::HINT => &mut self.hint_depth,
2756            _ => return,
2757        };
2758        if endpoint.is_start {
2759            *depth += 1;
2760        } else {
2761            *depth -= 1;
2762        }
2763
2764        if endpoint.is_unnecessary {
2765            if endpoint.is_start {
2766                self.unnecessary_depth += 1;
2767            } else {
2768                self.unnecessary_depth -= 1;
2769            }
2770        }
2771    }
2772
2773    fn current_diagnostic_severity(&self) -> Option<DiagnosticSeverity> {
2774        if self.error_depth > 0 {
2775            Some(DiagnosticSeverity::ERROR)
2776        } else if self.warning_depth > 0 {
2777            Some(DiagnosticSeverity::WARNING)
2778        } else if self.information_depth > 0 {
2779            Some(DiagnosticSeverity::INFORMATION)
2780        } else if self.hint_depth > 0 {
2781            Some(DiagnosticSeverity::HINT)
2782        } else {
2783            None
2784        }
2785    }
2786
2787    fn current_code_is_unnecessary(&self) -> bool {
2788        self.unnecessary_depth > 0
2789    }
2790}
2791
2792impl<'a> Iterator for BufferChunks<'a> {
2793    type Item = Chunk<'a>;
2794
2795    fn next(&mut self) -> Option<Self::Item> {
2796        let mut next_capture_start = usize::MAX;
2797        let mut next_diagnostic_endpoint = usize::MAX;
2798
2799        if let Some(highlights) = self.highlights.as_mut() {
2800            while let Some((parent_capture_end, _)) = highlights.stack.last() {
2801                if *parent_capture_end <= self.range.start {
2802                    highlights.stack.pop();
2803                } else {
2804                    break;
2805                }
2806            }
2807
2808            if highlights.next_capture.is_none() {
2809                highlights.next_capture = highlights.captures.next();
2810            }
2811
2812            while let Some(capture) = highlights.next_capture.as_ref() {
2813                if self.range.start < capture.node.start_byte() {
2814                    next_capture_start = capture.node.start_byte();
2815                    break;
2816                } else {
2817                    let highlight_id =
2818                        highlights.highlight_maps[capture.grammar_index].get(capture.index);
2819                    highlights
2820                        .stack
2821                        .push((capture.node.end_byte(), highlight_id));
2822                    highlights.next_capture = highlights.captures.next();
2823                }
2824            }
2825        }
2826
2827        while let Some(endpoint) = self.diagnostic_endpoints.peek().copied() {
2828            if endpoint.offset <= self.range.start {
2829                self.update_diagnostic_depths(endpoint);
2830                self.diagnostic_endpoints.next();
2831            } else {
2832                next_diagnostic_endpoint = endpoint.offset;
2833                break;
2834            }
2835        }
2836
2837        if let Some(chunk) = self.chunks.peek() {
2838            let chunk_start = self.range.start;
2839            let mut chunk_end = (self.chunks.offset() + chunk.len())
2840                .min(next_capture_start)
2841                .min(next_diagnostic_endpoint);
2842            let mut highlight_id = None;
2843            if let Some(highlights) = self.highlights.as_ref() {
2844                if let Some((parent_capture_end, parent_highlight_id)) = highlights.stack.last() {
2845                    chunk_end = chunk_end.min(*parent_capture_end);
2846                    highlight_id = Some(*parent_highlight_id);
2847                }
2848            }
2849
2850            let slice =
2851                &chunk[chunk_start - self.chunks.offset()..chunk_end - self.chunks.offset()];
2852            self.range.start = chunk_end;
2853            if self.range.start == self.chunks.offset() + chunk.len() {
2854                self.chunks.next().unwrap();
2855            }
2856
2857            Some(Chunk {
2858                text: slice,
2859                syntax_highlight_id: highlight_id,
2860                diagnostic_severity: self.current_diagnostic_severity(),
2861                is_unnecessary: self.current_code_is_unnecessary(),
2862                ..Default::default()
2863            })
2864        } else {
2865            None
2866        }
2867    }
2868}
2869
2870impl operation_queue::Operation for Operation {
2871    fn lamport_timestamp(&self) -> clock::Lamport {
2872        match self {
2873            Operation::Buffer(_) => {
2874                unreachable!("buffer operations should never be deferred at this layer")
2875            }
2876            Operation::UpdateDiagnostics {
2877                lamport_timestamp, ..
2878            }
2879            | Operation::UpdateSelections {
2880                lamport_timestamp, ..
2881            }
2882            | Operation::UpdateCompletionTriggers {
2883                lamport_timestamp, ..
2884            } => *lamport_timestamp,
2885        }
2886    }
2887}
2888
2889impl Default for Diagnostic {
2890    fn default() -> Self {
2891        Self {
2892            source: Default::default(),
2893            code: None,
2894            severity: DiagnosticSeverity::ERROR,
2895            message: Default::default(),
2896            group_id: 0,
2897            is_primary: false,
2898            is_valid: true,
2899            is_disk_based: false,
2900            is_unnecessary: false,
2901        }
2902    }
2903}
2904
2905impl IndentSize {
2906    pub fn spaces(len: u32) -> Self {
2907        Self {
2908            len,
2909            kind: IndentKind::Space,
2910        }
2911    }
2912
2913    pub fn tab() -> Self {
2914        Self {
2915            len: 1,
2916            kind: IndentKind::Tab,
2917        }
2918    }
2919
2920    pub fn chars(&self) -> impl Iterator<Item = char> {
2921        iter::repeat(self.char()).take(self.len as usize)
2922    }
2923
2924    pub fn char(&self) -> char {
2925        match self.kind {
2926            IndentKind::Space => ' ',
2927            IndentKind::Tab => '\t',
2928        }
2929    }
2930
2931    pub fn with_delta(mut self, direction: Ordering, size: IndentSize) -> Self {
2932        match direction {
2933            Ordering::Less => {
2934                if self.kind == size.kind && self.len >= size.len {
2935                    self.len -= size.len;
2936                }
2937            }
2938            Ordering::Equal => {}
2939            Ordering::Greater => {
2940                if self.len == 0 {
2941                    self = size;
2942                } else if self.kind == size.kind {
2943                    self.len += size.len;
2944                }
2945            }
2946        }
2947        self
2948    }
2949}
2950
2951impl Completion {
2952    pub fn sort_key(&self) -> (usize, &str) {
2953        let kind_key = match self.lsp_completion.kind {
2954            Some(lsp::CompletionItemKind::VARIABLE) => 0,
2955            _ => 1,
2956        };
2957        (kind_key, &self.label.text[self.label.filter_range.clone()])
2958    }
2959
2960    pub fn is_snippet(&self) -> bool {
2961        self.lsp_completion.insert_text_format == Some(lsp::InsertTextFormat::SNIPPET)
2962    }
2963}
2964
2965pub fn contiguous_ranges(
2966    values: impl Iterator<Item = u32>,
2967    max_len: usize,
2968) -> impl Iterator<Item = Range<u32>> {
2969    let mut values = values;
2970    let mut current_range: Option<Range<u32>> = None;
2971    std::iter::from_fn(move || loop {
2972        if let Some(value) = values.next() {
2973            if let Some(range) = &mut current_range {
2974                if value == range.end && range.len() < max_len {
2975                    range.end += 1;
2976                    continue;
2977                }
2978            }
2979
2980            let prev_range = current_range.clone();
2981            current_range = Some(value..(value + 1));
2982            if prev_range.is_some() {
2983                return prev_range;
2984            }
2985        } else {
2986            return current_range.take();
2987        }
2988    })
2989}
2990
2991pub fn char_kind(scope: &Option<LanguageScope>, c: char) -> CharKind {
2992    if c.is_whitespace() {
2993        return CharKind::Whitespace;
2994    } else if c.is_alphanumeric() || c == '_' {
2995        return CharKind::Word;
2996    }
2997
2998    if let Some(scope) = scope {
2999        if let Some(characters) = scope.word_characters() {
3000            if characters.contains(&c) {
3001                return CharKind::Word;
3002            }
3003        }
3004    }
3005
3006    CharKind::Punctuation
3007}
3008
3009/// Find all of the ranges of whitespace that occur at the ends of lines
3010/// in the given rope.
3011///
3012/// This could also be done with a regex search, but this implementation
3013/// avoids copying text.
3014pub fn trailing_whitespace_ranges(rope: &Rope) -> Vec<Range<usize>> {
3015    let mut ranges = Vec::new();
3016
3017    let mut offset = 0;
3018    let mut prev_chunk_trailing_whitespace_range = 0..0;
3019    for chunk in rope.chunks() {
3020        let mut prev_line_trailing_whitespace_range = 0..0;
3021        for (i, line) in chunk.split('\n').enumerate() {
3022            let line_end_offset = offset + line.len();
3023            let trimmed_line_len = line.trim_end_matches(|c| matches!(c, ' ' | '\t')).len();
3024            let mut trailing_whitespace_range = (offset + trimmed_line_len)..line_end_offset;
3025
3026            if i == 0 && trimmed_line_len == 0 {
3027                trailing_whitespace_range.start = prev_chunk_trailing_whitespace_range.start;
3028            }
3029            if !prev_line_trailing_whitespace_range.is_empty() {
3030                ranges.push(prev_line_trailing_whitespace_range);
3031            }
3032
3033            offset = line_end_offset + 1;
3034            prev_line_trailing_whitespace_range = trailing_whitespace_range;
3035        }
3036
3037        offset -= 1;
3038        prev_chunk_trailing_whitespace_range = prev_line_trailing_whitespace_range;
3039    }
3040
3041    if !prev_chunk_trailing_whitespace_range.is_empty() {
3042        ranges.push(prev_chunk_trailing_whitespace_range);
3043    }
3044
3045    ranges
3046}