1mod buffer;
2mod diagnostic_set;
3mod highlight_map;
4mod outline;
5pub mod proto;
6mod syntax_map;
7
8#[cfg(test)]
9mod buffer_tests;
10
11use anyhow::{anyhow, Context, Result};
12use async_trait::async_trait;
13use client::http::HttpClient;
14use collections::HashMap;
15use futures::{
16 channel::oneshot,
17 future::{BoxFuture, Shared},
18 FutureExt, TryFutureExt as _,
19};
20use gpui::{executor::Background, MutableAppContext, Task};
21use highlight_map::HighlightMap;
22use lazy_static::lazy_static;
23use parking_lot::{Mutex, RwLock};
24use postage::watch;
25use regex::Regex;
26use serde::{de, Deserialize, Deserializer};
27use serde_json::Value;
28use std::{
29 any::Any,
30 borrow::Cow,
31 cell::RefCell,
32 fmt::Debug,
33 hash::Hash,
34 mem,
35 ops::Range,
36 path::{Path, PathBuf},
37 str,
38 sync::{
39 atomic::{AtomicUsize, Ordering::SeqCst},
40 Arc,
41 },
42};
43use syntax_map::SyntaxSnapshot;
44use theme::{SyntaxTheme, Theme};
45use tree_sitter::{self, Query};
46use unicase::UniCase;
47use util::{merge_json_value_into, post_inc, ResultExt, TryFutureExt as _, UnwrapFuture};
48
49#[cfg(any(test, feature = "test-support"))]
50use futures::channel::mpsc;
51
52pub use buffer::Operation;
53pub use buffer::*;
54pub use diagnostic_set::DiagnosticEntry;
55pub use outline::{Outline, OutlineItem};
56pub use tree_sitter::{Parser, Tree};
57
58thread_local! {
59 static PARSER: RefCell<Parser> = RefCell::new(Parser::new());
60}
61
62lazy_static! {
63 pub static ref NEXT_GRAMMAR_ID: AtomicUsize = Default::default();
64 pub static ref PLAIN_TEXT: Arc<Language> = Arc::new(Language::new(
65 LanguageConfig {
66 name: "Plain Text".into(),
67 ..Default::default()
68 },
69 None,
70 ));
71}
72
73pub trait ToLspPosition {
74 fn to_lsp_position(self) -> lsp::Position;
75}
76
77#[derive(Clone, Debug, PartialEq, Eq, Hash)]
78pub struct LanguageServerName(pub Arc<str>);
79
80/// Represents a Language Server, with certain cached sync properties.
81/// Uses [`LspAdapter`] under the hood, but calls all 'static' methods
82/// once at startup, and caches the results.
83pub struct CachedLspAdapter {
84 pub name: LanguageServerName,
85 pub server_args: Vec<String>,
86 pub initialization_options: Option<Value>,
87 pub disk_based_diagnostic_sources: Vec<String>,
88 pub disk_based_diagnostics_progress_token: Option<String>,
89 pub language_ids: HashMap<String, String>,
90 pub adapter: Arc<dyn LspAdapter>,
91}
92
93impl CachedLspAdapter {
94 pub async fn new(adapter: Arc<dyn LspAdapter>) -> Arc<Self> {
95 let name = adapter.name().await;
96 let server_args = adapter.server_args().await;
97 let initialization_options = adapter.initialization_options().await;
98 let disk_based_diagnostic_sources = adapter.disk_based_diagnostic_sources().await;
99 let disk_based_diagnostics_progress_token =
100 adapter.disk_based_diagnostics_progress_token().await;
101 let language_ids = adapter.language_ids().await;
102
103 Arc::new(CachedLspAdapter {
104 name,
105 server_args,
106 initialization_options,
107 disk_based_diagnostic_sources,
108 disk_based_diagnostics_progress_token,
109 language_ids,
110 adapter,
111 })
112 }
113
114 pub async fn fetch_latest_server_version(
115 &self,
116 http: Arc<dyn HttpClient>,
117 ) -> Result<Box<dyn 'static + Send + Any>> {
118 self.adapter.fetch_latest_server_version(http).await
119 }
120
121 pub async fn fetch_server_binary(
122 &self,
123 version: Box<dyn 'static + Send + Any>,
124 http: Arc<dyn HttpClient>,
125 container_dir: PathBuf,
126 ) -> Result<PathBuf> {
127 self.adapter
128 .fetch_server_binary(version, http, container_dir)
129 .await
130 }
131
132 pub async fn cached_server_binary(&self, container_dir: PathBuf) -> Option<PathBuf> {
133 self.adapter.cached_server_binary(container_dir).await
134 }
135
136 pub fn workspace_configuration(
137 &self,
138 cx: &mut MutableAppContext,
139 ) -> Option<BoxFuture<'static, Value>> {
140 self.adapter.workspace_configuration(cx)
141 }
142
143 pub async fn process_diagnostics(&self, params: &mut lsp::PublishDiagnosticsParams) {
144 self.adapter.process_diagnostics(params).await
145 }
146
147 pub async fn process_completion(&self, completion_item: &mut lsp::CompletionItem) {
148 self.adapter.process_completion(completion_item).await
149 }
150
151 pub async fn label_for_completion(
152 &self,
153 completion_item: &lsp::CompletionItem,
154 language: &Arc<Language>,
155 ) -> Option<CodeLabel> {
156 self.adapter
157 .label_for_completion(completion_item, language)
158 .await
159 }
160
161 pub async fn label_for_symbol(
162 &self,
163 name: &str,
164 kind: lsp::SymbolKind,
165 language: &Arc<Language>,
166 ) -> Option<CodeLabel> {
167 self.adapter.label_for_symbol(name, kind, language).await
168 }
169}
170
171#[async_trait]
172pub trait LspAdapter: 'static + Send + Sync {
173 async fn name(&self) -> LanguageServerName;
174
175 async fn fetch_latest_server_version(
176 &self,
177 http: Arc<dyn HttpClient>,
178 ) -> Result<Box<dyn 'static + Send + Any>>;
179
180 async fn fetch_server_binary(
181 &self,
182 version: Box<dyn 'static + Send + Any>,
183 http: Arc<dyn HttpClient>,
184 container_dir: PathBuf,
185 ) -> Result<PathBuf>;
186
187 async fn cached_server_binary(&self, container_dir: PathBuf) -> Option<PathBuf>;
188
189 async fn process_diagnostics(&self, _: &mut lsp::PublishDiagnosticsParams) {}
190
191 async fn process_completion(&self, _: &mut lsp::CompletionItem) {}
192
193 async fn label_for_completion(
194 &self,
195 _: &lsp::CompletionItem,
196 _: &Arc<Language>,
197 ) -> Option<CodeLabel> {
198 None
199 }
200
201 async fn label_for_symbol(
202 &self,
203 _: &str,
204 _: lsp::SymbolKind,
205 _: &Arc<Language>,
206 ) -> Option<CodeLabel> {
207 None
208 }
209
210 async fn server_args(&self) -> Vec<String> {
211 Vec::new()
212 }
213
214 async fn initialization_options(&self) -> Option<Value> {
215 None
216 }
217
218 fn workspace_configuration(
219 &self,
220 _: &mut MutableAppContext,
221 ) -> Option<BoxFuture<'static, Value>> {
222 None
223 }
224
225 async fn disk_based_diagnostic_sources(&self) -> Vec<String> {
226 Default::default()
227 }
228
229 async fn disk_based_diagnostics_progress_token(&self) -> Option<String> {
230 None
231 }
232
233 async fn language_ids(&self) -> HashMap<String, String> {
234 Default::default()
235 }
236}
237
238#[derive(Clone, Debug, PartialEq, Eq)]
239pub struct CodeLabel {
240 pub text: String,
241 pub runs: Vec<(Range<usize>, HighlightId)>,
242 pub filter_range: Range<usize>,
243}
244
245#[derive(Clone, Deserialize)]
246pub struct LanguageConfig {
247 pub name: Arc<str>,
248 pub path_suffixes: Vec<String>,
249 pub brackets: BracketPairConfig,
250 #[serde(default = "auto_indent_using_last_non_empty_line_default")]
251 pub auto_indent_using_last_non_empty_line: bool,
252 #[serde(default, deserialize_with = "deserialize_regex")]
253 pub increase_indent_pattern: Option<Regex>,
254 #[serde(default, deserialize_with = "deserialize_regex")]
255 pub decrease_indent_pattern: Option<Regex>,
256 #[serde(default)]
257 pub autoclose_before: String,
258 #[serde(default)]
259 pub line_comment: Option<Arc<str>>,
260 #[serde(default)]
261 pub block_comment: Option<(Arc<str>, Arc<str>)>,
262 #[serde(default)]
263 pub overrides: HashMap<String, LanguageConfigOverride>,
264}
265
266#[derive(Debug, Default)]
267pub struct LanguageQueries {
268 pub highlights: Option<Cow<'static, str>>,
269 pub brackets: Option<Cow<'static, str>>,
270 pub indents: Option<Cow<'static, str>>,
271 pub outline: Option<Cow<'static, str>>,
272 pub injections: Option<Cow<'static, str>>,
273 pub overrides: Option<Cow<'static, str>>,
274}
275
276#[derive(Clone, Debug)]
277pub struct LanguageScope {
278 language: Arc<Language>,
279 override_id: Option<u32>,
280}
281
282#[derive(Clone, Deserialize, Default, Debug)]
283pub struct LanguageConfigOverride {
284 #[serde(default)]
285 pub line_comment: Override<Arc<str>>,
286 #[serde(default)]
287 pub block_comment: Override<(Arc<str>, Arc<str>)>,
288 #[serde(skip_deserializing)]
289 pub disabled_bracket_ixs: Vec<u16>,
290}
291
292#[derive(Clone, Deserialize, Debug)]
293#[serde(untagged)]
294pub enum Override<T> {
295 Remove { remove: bool },
296 Set(T),
297}
298
299impl<T> Default for Override<T> {
300 fn default() -> Self {
301 Override::Remove { remove: false }
302 }
303}
304
305impl<T> Override<T> {
306 fn as_option<'a>(this: Option<&'a Self>, original: Option<&'a T>) -> Option<&'a T> {
307 match this {
308 Some(Self::Set(value)) => Some(value),
309 Some(Self::Remove { remove: true }) => None,
310 Some(Self::Remove { remove: false }) | None => original,
311 }
312 }
313}
314
315impl Default for LanguageConfig {
316 fn default() -> Self {
317 Self {
318 name: "".into(),
319 path_suffixes: Default::default(),
320 brackets: Default::default(),
321 auto_indent_using_last_non_empty_line: auto_indent_using_last_non_empty_line_default(),
322 increase_indent_pattern: Default::default(),
323 decrease_indent_pattern: Default::default(),
324 autoclose_before: Default::default(),
325 line_comment: Default::default(),
326 block_comment: Default::default(),
327 overrides: Default::default(),
328 }
329 }
330}
331
332fn auto_indent_using_last_non_empty_line_default() -> bool {
333 true
334}
335
336fn deserialize_regex<'de, D: Deserializer<'de>>(d: D) -> Result<Option<Regex>, D::Error> {
337 let source = Option::<String>::deserialize(d)?;
338 if let Some(source) = source {
339 Ok(Some(regex::Regex::new(&source).map_err(de::Error::custom)?))
340 } else {
341 Ok(None)
342 }
343}
344
345#[cfg(any(test, feature = "test-support"))]
346pub struct FakeLspAdapter {
347 pub name: &'static str,
348 pub capabilities: lsp::ServerCapabilities,
349 pub initializer: Option<Box<dyn 'static + Send + Sync + Fn(&mut lsp::FakeLanguageServer)>>,
350 pub disk_based_diagnostics_progress_token: Option<String>,
351 pub disk_based_diagnostics_sources: Vec<String>,
352}
353
354#[derive(Clone, Debug, Default)]
355pub struct BracketPairConfig {
356 pub pairs: Vec<BracketPair>,
357 pub disabled_scopes_by_bracket_ix: Vec<Vec<String>>,
358}
359
360impl<'de> Deserialize<'de> for BracketPairConfig {
361 fn deserialize<D>(deserializer: D) -> std::result::Result<Self, D::Error>
362 where
363 D: Deserializer<'de>,
364 {
365 #[derive(Deserialize)]
366 pub struct Entry {
367 #[serde(flatten)]
368 pub bracket_pair: BracketPair,
369 #[serde(default)]
370 pub not_in: Vec<String>,
371 }
372
373 let result = Vec::<Entry>::deserialize(deserializer)?;
374 let mut brackets = Vec::with_capacity(result.len());
375 let mut disabled_scopes_by_bracket_ix = Vec::with_capacity(result.len());
376 for entry in result {
377 brackets.push(entry.bracket_pair);
378 disabled_scopes_by_bracket_ix.push(entry.not_in);
379 }
380
381 Ok(BracketPairConfig {
382 pairs: brackets,
383 disabled_scopes_by_bracket_ix,
384 })
385 }
386}
387
388#[derive(Clone, Debug, Default, Deserialize, PartialEq)]
389pub struct BracketPair {
390 pub start: String,
391 pub end: String,
392 pub close: bool,
393 pub newline: bool,
394}
395
396pub struct Language {
397 pub(crate) config: LanguageConfig,
398 pub(crate) grammar: Option<Arc<Grammar>>,
399 pub(crate) adapter: Option<Arc<CachedLspAdapter>>,
400
401 #[cfg(any(test, feature = "test-support"))]
402 fake_adapter: Option<(
403 mpsc::UnboundedSender<lsp::FakeLanguageServer>,
404 Arc<FakeLspAdapter>,
405 )>,
406}
407
408pub struct Grammar {
409 id: usize,
410 pub(crate) ts_language: tree_sitter::Language,
411 pub(crate) error_query: Query,
412 pub(crate) highlights_query: Option<Query>,
413 pub(crate) brackets_config: Option<BracketConfig>,
414 pub(crate) indents_config: Option<IndentConfig>,
415 pub(crate) outline_config: Option<OutlineConfig>,
416 pub(crate) injection_config: Option<InjectionConfig>,
417 pub(crate) override_config: Option<OverrideConfig>,
418 pub(crate) highlight_map: Mutex<HighlightMap>,
419}
420
421struct IndentConfig {
422 query: Query,
423 indent_capture_ix: u32,
424 start_capture_ix: Option<u32>,
425 end_capture_ix: Option<u32>,
426 outdent_capture_ix: Option<u32>,
427}
428
429struct OutlineConfig {
430 query: Query,
431 item_capture_ix: u32,
432 name_capture_ix: u32,
433 context_capture_ix: Option<u32>,
434}
435
436struct InjectionConfig {
437 query: Query,
438 content_capture_ix: u32,
439 language_capture_ix: Option<u32>,
440 patterns: Vec<InjectionPatternConfig>,
441}
442
443struct OverrideConfig {
444 query: Query,
445 values: HashMap<u32, (String, LanguageConfigOverride)>,
446}
447
448#[derive(Default, Clone)]
449struct InjectionPatternConfig {
450 language: Option<Box<str>>,
451 combined: bool,
452}
453
454struct BracketConfig {
455 query: Query,
456 open_capture_ix: u32,
457 close_capture_ix: u32,
458}
459
460#[derive(Clone)]
461pub enum LanguageServerBinaryStatus {
462 CheckingForUpdate,
463 Downloading,
464 Downloaded,
465 Cached,
466 Failed { error: String },
467}
468
469type AvailableLanguageId = usize;
470
471#[derive(Clone)]
472struct AvailableLanguage {
473 id: AvailableLanguageId,
474 path: &'static str,
475 config: LanguageConfig,
476 grammar: tree_sitter::Language,
477 lsp_adapter: Option<Arc<dyn LspAdapter>>,
478 get_queries: fn(&str) -> LanguageQueries,
479}
480
481pub struct LanguageRegistry {
482 state: RwLock<LanguageRegistryState>,
483 language_server_download_dir: Option<Arc<Path>>,
484 lsp_binary_statuses_tx: async_broadcast::Sender<(Arc<Language>, LanguageServerBinaryStatus)>,
485 lsp_binary_statuses_rx: async_broadcast::Receiver<(Arc<Language>, LanguageServerBinaryStatus)>,
486 login_shell_env_loaded: Shared<Task<()>>,
487 #[allow(clippy::type_complexity)]
488 lsp_binary_paths: Mutex<
489 HashMap<
490 LanguageServerName,
491 Shared<BoxFuture<'static, Result<PathBuf, Arc<anyhow::Error>>>>,
492 >,
493 >,
494 executor: Option<Arc<Background>>,
495}
496
497struct LanguageRegistryState {
498 languages: Vec<Arc<Language>>,
499 available_languages: Vec<AvailableLanguage>,
500 next_available_language_id: AvailableLanguageId,
501 loading_languages: HashMap<AvailableLanguageId, Vec<oneshot::Sender<Result<Arc<Language>>>>>,
502 subscription: (watch::Sender<()>, watch::Receiver<()>),
503 theme: Option<Arc<Theme>>,
504 version: usize,
505}
506
507impl LanguageRegistry {
508 pub fn new(login_shell_env_loaded: Task<()>) -> Self {
509 let (lsp_binary_statuses_tx, lsp_binary_statuses_rx) = async_broadcast::broadcast(16);
510 Self {
511 state: RwLock::new(LanguageRegistryState {
512 languages: vec![PLAIN_TEXT.clone()],
513 available_languages: Default::default(),
514 next_available_language_id: 0,
515 loading_languages: Default::default(),
516 subscription: watch::channel(),
517 theme: Default::default(),
518 version: 0,
519 }),
520 language_server_download_dir: None,
521 lsp_binary_statuses_tx,
522 lsp_binary_statuses_rx,
523 login_shell_env_loaded: login_shell_env_loaded.shared(),
524 lsp_binary_paths: Default::default(),
525 executor: None,
526 }
527 }
528
529 #[cfg(any(test, feature = "test-support"))]
530 pub fn test() -> Self {
531 Self::new(Task::ready(()))
532 }
533
534 pub fn set_executor(&mut self, executor: Arc<Background>) {
535 self.executor = Some(executor);
536 }
537
538 pub fn register(
539 &self,
540 path: &'static str,
541 config: LanguageConfig,
542 grammar: tree_sitter::Language,
543 lsp_adapter: Option<Arc<dyn LspAdapter>>,
544 get_queries: fn(&str) -> LanguageQueries,
545 ) {
546 let state = &mut *self.state.write();
547 state.available_languages.push(AvailableLanguage {
548 id: post_inc(&mut state.next_available_language_id),
549 path,
550 config,
551 grammar,
552 lsp_adapter,
553 get_queries,
554 });
555 }
556
557 pub fn language_names(&self) -> Vec<String> {
558 let state = self.state.read();
559 let mut result = state
560 .available_languages
561 .iter()
562 .map(|l| l.config.name.to_string())
563 .chain(state.languages.iter().map(|l| l.config.name.to_string()))
564 .collect::<Vec<_>>();
565 result.sort_unstable_by_key(|language_name| language_name.to_lowercase());
566 result
567 }
568
569 pub fn workspace_configuration(&self, cx: &mut MutableAppContext) -> Task<serde_json::Value> {
570 let state = self.state.read();
571 let mut language_configs = Vec::new();
572 for language in &state.available_languages {
573 if let Some(adapter) = language.lsp_adapter.as_ref() {
574 if let Some(language_config) = adapter.workspace_configuration(cx) {
575 language_configs.push(language_config);
576 }
577 }
578 }
579 for language in &state.languages {
580 if let Some(adapter) = language.lsp_adapter() {
581 if let Some(language_config) = adapter.workspace_configuration(cx) {
582 language_configs.push(language_config);
583 }
584 }
585 }
586
587 cx.background().spawn(async move {
588 let mut config = serde_json::json!({});
589 let language_configs = futures::future::join_all(language_configs).await;
590 for language_config in language_configs {
591 merge_json_value_into(language_config, &mut config);
592 }
593 config
594 })
595 }
596
597 pub fn add(&self, language: Arc<Language>) {
598 self.state.write().add(language);
599 }
600
601 pub fn subscribe(&self) -> watch::Receiver<()> {
602 self.state.read().subscription.1.clone()
603 }
604
605 pub fn version(&self) -> usize {
606 self.state.read().version
607 }
608
609 pub fn set_theme(&self, theme: Arc<Theme>) {
610 let mut state = self.state.write();
611 state.theme = Some(theme.clone());
612 for language in &state.languages {
613 language.set_theme(&theme.editor.syntax);
614 }
615 }
616
617 pub fn set_language_server_download_dir(&mut self, path: impl Into<Arc<Path>>) {
618 self.language_server_download_dir = Some(path.into());
619 }
620
621 pub fn language_for_name(
622 self: &Arc<Self>,
623 name: &str,
624 ) -> UnwrapFuture<oneshot::Receiver<Result<Arc<Language>>>> {
625 let name = UniCase::new(name);
626 self.get_or_load_language(|config| UniCase::new(config.name.as_ref()) == name)
627 }
628
629 pub fn language_for_name_or_extension(
630 self: &Arc<Self>,
631 string: &str,
632 ) -> UnwrapFuture<oneshot::Receiver<Result<Arc<Language>>>> {
633 let string = UniCase::new(string);
634 self.get_or_load_language(|config| {
635 UniCase::new(config.name.as_ref()) == string
636 || config
637 .path_suffixes
638 .iter()
639 .any(|suffix| UniCase::new(suffix) == string)
640 })
641 }
642
643 pub fn language_for_path(
644 self: &Arc<Self>,
645 path: impl AsRef<Path>,
646 ) -> UnwrapFuture<oneshot::Receiver<Result<Arc<Language>>>> {
647 let path = path.as_ref();
648 let filename = path.file_name().and_then(|name| name.to_str());
649 let extension = path.extension().and_then(|name| name.to_str());
650 let path_suffixes = [extension, filename];
651 self.get_or_load_language(|config| {
652 config
653 .path_suffixes
654 .iter()
655 .any(|suffix| path_suffixes.contains(&Some(suffix.as_str())))
656 })
657 }
658
659 fn get_or_load_language(
660 self: &Arc<Self>,
661 callback: impl Fn(&LanguageConfig) -> bool,
662 ) -> UnwrapFuture<oneshot::Receiver<Result<Arc<Language>>>> {
663 let (tx, rx) = oneshot::channel();
664
665 let mut state = self.state.write();
666 if let Some(language) = state
667 .languages
668 .iter()
669 .find(|language| callback(&language.config))
670 {
671 let _ = tx.send(Ok(language.clone()));
672 } else if let Some(executor) = self.executor.clone() {
673 if let Some(language) = state
674 .available_languages
675 .iter()
676 .find(|l| callback(&l.config))
677 .cloned()
678 {
679 let txs = state
680 .loading_languages
681 .entry(language.id)
682 .or_insert_with(|| {
683 let this = self.clone();
684 executor
685 .spawn(async move {
686 let id = language.id;
687 let queries = (language.get_queries)(&language.path);
688 let language =
689 Language::new(language.config, Some(language.grammar))
690 .with_lsp_adapter(language.lsp_adapter)
691 .await;
692 let name = language.name();
693 match language.with_queries(queries) {
694 Ok(language) => {
695 let language = Arc::new(language);
696 let mut state = this.state.write();
697 state.add(language.clone());
698 state
699 .available_languages
700 .retain(|language| language.id != id);
701 if let Some(mut txs) = state.loading_languages.remove(&id) {
702 for tx in txs.drain(..) {
703 let _ = tx.send(Ok(language.clone()));
704 }
705 }
706 }
707 Err(err) => {
708 let mut state = this.state.write();
709 state
710 .available_languages
711 .retain(|language| language.id != id);
712 if let Some(mut txs) = state.loading_languages.remove(&id) {
713 for tx in txs.drain(..) {
714 let _ = tx.send(Err(anyhow!(
715 "failed to load language {}: {}",
716 name,
717 err
718 )));
719 }
720 }
721 }
722 };
723 })
724 .detach();
725
726 Vec::new()
727 });
728 txs.push(tx);
729 } else {
730 let _ = tx.send(Err(anyhow!("language not found")));
731 }
732 } else {
733 let _ = tx.send(Err(anyhow!("executor does not exist")));
734 }
735
736 rx.unwrap()
737 }
738
739 pub fn to_vec(&self) -> Vec<Arc<Language>> {
740 self.state.read().languages.iter().cloned().collect()
741 }
742
743 pub fn start_language_server(
744 self: &Arc<Self>,
745 server_id: usize,
746 language: Arc<Language>,
747 root_path: Arc<Path>,
748 http_client: Arc<dyn HttpClient>,
749 cx: &mut MutableAppContext,
750 ) -> Option<Task<Result<lsp::LanguageServer>>> {
751 #[cfg(any(test, feature = "test-support"))]
752 if language.fake_adapter.is_some() {
753 let language = language;
754 return Some(cx.spawn(|cx| async move {
755 let (servers_tx, fake_adapter) = language.fake_adapter.as_ref().unwrap();
756 let (server, mut fake_server) = lsp::LanguageServer::fake(
757 fake_adapter.name.to_string(),
758 fake_adapter.capabilities.clone(),
759 cx.clone(),
760 );
761
762 if let Some(initializer) = &fake_adapter.initializer {
763 initializer(&mut fake_server);
764 }
765
766 let servers_tx = servers_tx.clone();
767 cx.background()
768 .spawn(async move {
769 if fake_server
770 .try_receive_notification::<lsp::notification::Initialized>()
771 .await
772 .is_some()
773 {
774 servers_tx.unbounded_send(fake_server).ok();
775 }
776 })
777 .detach();
778 Ok(server)
779 }));
780 }
781
782 let download_dir = self
783 .language_server_download_dir
784 .clone()
785 .ok_or_else(|| anyhow!("language server download directory has not been assigned"))
786 .log_err()?;
787
788 let this = self.clone();
789 let adapter = language.adapter.clone()?;
790 let lsp_binary_statuses = self.lsp_binary_statuses_tx.clone();
791 let login_shell_env_loaded = self.login_shell_env_loaded.clone();
792 Some(cx.spawn(|cx| async move {
793 login_shell_env_loaded.await;
794 let server_binary_path = this
795 .lsp_binary_paths
796 .lock()
797 .entry(adapter.name.clone())
798 .or_insert_with(|| {
799 get_server_binary_path(
800 adapter.clone(),
801 language.clone(),
802 http_client,
803 download_dir,
804 lsp_binary_statuses,
805 )
806 .map_err(Arc::new)
807 .boxed()
808 .shared()
809 })
810 .clone()
811 .map_err(|e| anyhow!(e));
812
813 let server_binary_path = server_binary_path.await?;
814 let server_args = &adapter.server_args;
815 let server = lsp::LanguageServer::new(
816 server_id,
817 &server_binary_path,
818 server_args,
819 &root_path,
820 cx,
821 )?;
822 Ok(server)
823 }))
824 }
825
826 pub fn language_server_binary_statuses(
827 &self,
828 ) -> async_broadcast::Receiver<(Arc<Language>, LanguageServerBinaryStatus)> {
829 self.lsp_binary_statuses_rx.clone()
830 }
831}
832
833impl LanguageRegistryState {
834 fn add(&mut self, language: Arc<Language>) {
835 if let Some(theme) = self.theme.as_ref() {
836 language.set_theme(&theme.editor.syntax);
837 }
838 self.languages.push(language);
839 self.version += 1;
840 *self.subscription.0.borrow_mut() = ();
841 }
842}
843
844#[cfg(any(test, feature = "test-support"))]
845impl Default for LanguageRegistry {
846 fn default() -> Self {
847 Self::test()
848 }
849}
850
851async fn get_server_binary_path(
852 adapter: Arc<CachedLspAdapter>,
853 language: Arc<Language>,
854 http_client: Arc<dyn HttpClient>,
855 download_dir: Arc<Path>,
856 statuses: async_broadcast::Sender<(Arc<Language>, LanguageServerBinaryStatus)>,
857) -> Result<PathBuf> {
858 let container_dir = download_dir.join(adapter.name.0.as_ref());
859 if !container_dir.exists() {
860 smol::fs::create_dir_all(&container_dir)
861 .await
862 .context("failed to create container directory")?;
863 }
864
865 let path = fetch_latest_server_binary_path(
866 adapter.clone(),
867 language.clone(),
868 http_client,
869 &container_dir,
870 statuses.clone(),
871 )
872 .await;
873 if let Err(error) = path.as_ref() {
874 if let Some(cached_path) = adapter.cached_server_binary(container_dir).await {
875 statuses
876 .broadcast((language.clone(), LanguageServerBinaryStatus::Cached))
877 .await?;
878 return Ok(cached_path);
879 } else {
880 statuses
881 .broadcast((
882 language.clone(),
883 LanguageServerBinaryStatus::Failed {
884 error: format!("{:?}", error),
885 },
886 ))
887 .await?;
888 }
889 }
890 path
891}
892
893async fn fetch_latest_server_binary_path(
894 adapter: Arc<CachedLspAdapter>,
895 language: Arc<Language>,
896 http_client: Arc<dyn HttpClient>,
897 container_dir: &Path,
898 lsp_binary_statuses_tx: async_broadcast::Sender<(Arc<Language>, LanguageServerBinaryStatus)>,
899) -> Result<PathBuf> {
900 let container_dir: Arc<Path> = container_dir.into();
901 lsp_binary_statuses_tx
902 .broadcast((
903 language.clone(),
904 LanguageServerBinaryStatus::CheckingForUpdate,
905 ))
906 .await?;
907 let version_info = adapter
908 .fetch_latest_server_version(http_client.clone())
909 .await?;
910 lsp_binary_statuses_tx
911 .broadcast((language.clone(), LanguageServerBinaryStatus::Downloading))
912 .await?;
913 let path = adapter
914 .fetch_server_binary(version_info, http_client, container_dir.to_path_buf())
915 .await?;
916 lsp_binary_statuses_tx
917 .broadcast((language.clone(), LanguageServerBinaryStatus::Downloaded))
918 .await?;
919 Ok(path)
920}
921
922impl Language {
923 pub fn new(config: LanguageConfig, ts_language: Option<tree_sitter::Language>) -> Self {
924 Self {
925 config,
926 grammar: ts_language.map(|ts_language| {
927 Arc::new(Grammar {
928 id: NEXT_GRAMMAR_ID.fetch_add(1, SeqCst),
929 highlights_query: None,
930 brackets_config: None,
931 outline_config: None,
932 indents_config: None,
933 injection_config: None,
934 override_config: None,
935 error_query: Query::new(ts_language, "(ERROR) @error").unwrap(),
936 ts_language,
937 highlight_map: Default::default(),
938 })
939 }),
940 adapter: None,
941
942 #[cfg(any(test, feature = "test-support"))]
943 fake_adapter: None,
944 }
945 }
946
947 pub fn lsp_adapter(&self) -> Option<Arc<CachedLspAdapter>> {
948 self.adapter.clone()
949 }
950
951 pub fn id(&self) -> Option<usize> {
952 self.grammar.as_ref().map(|g| g.id)
953 }
954
955 pub fn with_queries(mut self, queries: LanguageQueries) -> Result<Self> {
956 if let Some(query) = queries.highlights {
957 self = self
958 .with_highlights_query(query.as_ref())
959 .expect("failed to evaluate highlights query");
960 }
961 if let Some(query) = queries.brackets {
962 self = self
963 .with_brackets_query(query.as_ref())
964 .expect("failed to load brackets query");
965 }
966 if let Some(query) = queries.indents {
967 self = self
968 .with_indents_query(query.as_ref())
969 .expect("failed to load indents query");
970 }
971 if let Some(query) = queries.outline {
972 self = self
973 .with_outline_query(query.as_ref())
974 .expect("failed to load outline query");
975 }
976 if let Some(query) = queries.injections {
977 self = self
978 .with_injection_query(query.as_ref())
979 .expect("failed to load injection query");
980 }
981 if let Some(query) = queries.overrides {
982 self = self
983 .with_override_query(query.as_ref())
984 .expect("failed to load override query");
985 }
986 Ok(self)
987 }
988 pub fn with_highlights_query(mut self, source: &str) -> Result<Self> {
989 let grammar = self.grammar_mut();
990 grammar.highlights_query = Some(Query::new(grammar.ts_language, source)?);
991 Ok(self)
992 }
993
994 pub fn with_outline_query(mut self, source: &str) -> Result<Self> {
995 let grammar = self.grammar_mut();
996 let query = Query::new(grammar.ts_language, source)?;
997 let mut item_capture_ix = None;
998 let mut name_capture_ix = None;
999 let mut context_capture_ix = None;
1000 get_capture_indices(
1001 &query,
1002 &mut [
1003 ("item", &mut item_capture_ix),
1004 ("name", &mut name_capture_ix),
1005 ("context", &mut context_capture_ix),
1006 ],
1007 );
1008 if let Some((item_capture_ix, name_capture_ix)) = item_capture_ix.zip(name_capture_ix) {
1009 grammar.outline_config = Some(OutlineConfig {
1010 query,
1011 item_capture_ix,
1012 name_capture_ix,
1013 context_capture_ix,
1014 });
1015 }
1016 Ok(self)
1017 }
1018
1019 pub fn with_brackets_query(mut self, source: &str) -> Result<Self> {
1020 let grammar = self.grammar_mut();
1021 let query = Query::new(grammar.ts_language, source)?;
1022 let mut open_capture_ix = None;
1023 let mut close_capture_ix = None;
1024 get_capture_indices(
1025 &query,
1026 &mut [
1027 ("open", &mut open_capture_ix),
1028 ("close", &mut close_capture_ix),
1029 ],
1030 );
1031 if let Some((open_capture_ix, close_capture_ix)) = open_capture_ix.zip(close_capture_ix) {
1032 grammar.brackets_config = Some(BracketConfig {
1033 query,
1034 open_capture_ix,
1035 close_capture_ix,
1036 });
1037 }
1038 Ok(self)
1039 }
1040
1041 pub fn with_indents_query(mut self, source: &str) -> Result<Self> {
1042 let grammar = self.grammar_mut();
1043 let query = Query::new(grammar.ts_language, source)?;
1044 let mut indent_capture_ix = None;
1045 let mut start_capture_ix = None;
1046 let mut end_capture_ix = None;
1047 let mut outdent_capture_ix = None;
1048 get_capture_indices(
1049 &query,
1050 &mut [
1051 ("indent", &mut indent_capture_ix),
1052 ("start", &mut start_capture_ix),
1053 ("end", &mut end_capture_ix),
1054 ("outdent", &mut outdent_capture_ix),
1055 ],
1056 );
1057 if let Some(indent_capture_ix) = indent_capture_ix {
1058 grammar.indents_config = Some(IndentConfig {
1059 query,
1060 indent_capture_ix,
1061 start_capture_ix,
1062 end_capture_ix,
1063 outdent_capture_ix,
1064 });
1065 }
1066 Ok(self)
1067 }
1068
1069 pub fn with_injection_query(mut self, source: &str) -> Result<Self> {
1070 let grammar = self.grammar_mut();
1071 let query = Query::new(grammar.ts_language, source)?;
1072 let mut language_capture_ix = None;
1073 let mut content_capture_ix = None;
1074 get_capture_indices(
1075 &query,
1076 &mut [
1077 ("language", &mut language_capture_ix),
1078 ("content", &mut content_capture_ix),
1079 ],
1080 );
1081 let patterns = (0..query.pattern_count())
1082 .map(|ix| {
1083 let mut config = InjectionPatternConfig::default();
1084 for setting in query.property_settings(ix) {
1085 match setting.key.as_ref() {
1086 "language" => {
1087 config.language = setting.value.clone();
1088 }
1089 "combined" => {
1090 config.combined = true;
1091 }
1092 _ => {}
1093 }
1094 }
1095 config
1096 })
1097 .collect();
1098 if let Some(content_capture_ix) = content_capture_ix {
1099 grammar.injection_config = Some(InjectionConfig {
1100 query,
1101 language_capture_ix,
1102 content_capture_ix,
1103 patterns,
1104 });
1105 }
1106 Ok(self)
1107 }
1108
1109 pub fn with_override_query(mut self, source: &str) -> Result<Self> {
1110 let query = Query::new(self.grammar_mut().ts_language, source)?;
1111
1112 let mut override_configs_by_id = HashMap::default();
1113 for (ix, name) in query.capture_names().iter().enumerate() {
1114 if !name.starts_with('_') {
1115 let value = self.config.overrides.remove(name).unwrap_or_default();
1116 override_configs_by_id.insert(ix as u32, (name.clone(), value));
1117 }
1118 }
1119
1120 if !self.config.overrides.is_empty() {
1121 let keys = self.config.overrides.keys().collect::<Vec<_>>();
1122 Err(anyhow!(
1123 "language {:?} has overrides in config not in query: {keys:?}",
1124 self.config.name
1125 ))?;
1126 }
1127
1128 for disabled_scope_name in self
1129 .config
1130 .brackets
1131 .disabled_scopes_by_bracket_ix
1132 .iter()
1133 .flatten()
1134 {
1135 if !override_configs_by_id
1136 .values()
1137 .any(|(scope_name, _)| scope_name == disabled_scope_name)
1138 {
1139 Err(anyhow!(
1140 "language {:?} has overrides in config not in query: {disabled_scope_name:?}",
1141 self.config.name
1142 ))?;
1143 }
1144 }
1145
1146 for (name, override_config) in override_configs_by_id.values_mut() {
1147 override_config.disabled_bracket_ixs = self
1148 .config
1149 .brackets
1150 .disabled_scopes_by_bracket_ix
1151 .iter()
1152 .enumerate()
1153 .filter_map(|(ix, disabled_scope_names)| {
1154 if disabled_scope_names.contains(name) {
1155 Some(ix as u16)
1156 } else {
1157 None
1158 }
1159 })
1160 .collect();
1161 }
1162
1163 self.config.brackets.disabled_scopes_by_bracket_ix.clear();
1164 self.grammar_mut().override_config = Some(OverrideConfig {
1165 query,
1166 values: override_configs_by_id,
1167 });
1168 Ok(self)
1169 }
1170
1171 fn grammar_mut(&mut self) -> &mut Grammar {
1172 Arc::get_mut(self.grammar.as_mut().unwrap()).unwrap()
1173 }
1174
1175 pub async fn with_lsp_adapter(mut self, lsp_adapter: Option<Arc<dyn LspAdapter>>) -> Self {
1176 if let Some(adapter) = lsp_adapter {
1177 self.adapter = Some(CachedLspAdapter::new(adapter).await);
1178 }
1179 self
1180 }
1181
1182 #[cfg(any(test, feature = "test-support"))]
1183 pub async fn set_fake_lsp_adapter(
1184 &mut self,
1185 fake_lsp_adapter: Arc<FakeLspAdapter>,
1186 ) -> mpsc::UnboundedReceiver<lsp::FakeLanguageServer> {
1187 let (servers_tx, servers_rx) = mpsc::unbounded();
1188 self.fake_adapter = Some((servers_tx, fake_lsp_adapter.clone()));
1189 let adapter = CachedLspAdapter::new(Arc::new(fake_lsp_adapter)).await;
1190 self.adapter = Some(adapter);
1191 servers_rx
1192 }
1193
1194 pub fn name(&self) -> Arc<str> {
1195 self.config.name.clone()
1196 }
1197
1198 pub async fn disk_based_diagnostic_sources(&self) -> &[String] {
1199 match self.adapter.as_ref() {
1200 Some(adapter) => &adapter.disk_based_diagnostic_sources,
1201 None => &[],
1202 }
1203 }
1204
1205 pub async fn disk_based_diagnostics_progress_token(&self) -> Option<&str> {
1206 if let Some(adapter) = self.adapter.as_ref() {
1207 adapter.disk_based_diagnostics_progress_token.as_deref()
1208 } else {
1209 None
1210 }
1211 }
1212
1213 pub async fn process_diagnostics(&self, diagnostics: &mut lsp::PublishDiagnosticsParams) {
1214 if let Some(processor) = self.adapter.as_ref() {
1215 processor.process_diagnostics(diagnostics).await;
1216 }
1217 }
1218
1219 pub async fn process_completion(self: &Arc<Self>, completion: &mut lsp::CompletionItem) {
1220 if let Some(adapter) = self.adapter.as_ref() {
1221 adapter.process_completion(completion).await;
1222 }
1223 }
1224
1225 pub async fn label_for_completion(
1226 self: &Arc<Self>,
1227 completion: &lsp::CompletionItem,
1228 ) -> Option<CodeLabel> {
1229 self.adapter
1230 .as_ref()?
1231 .label_for_completion(completion, self)
1232 .await
1233 }
1234
1235 pub async fn label_for_symbol(
1236 self: &Arc<Self>,
1237 name: &str,
1238 kind: lsp::SymbolKind,
1239 ) -> Option<CodeLabel> {
1240 self.adapter
1241 .as_ref()?
1242 .label_for_symbol(name, kind, self)
1243 .await
1244 }
1245
1246 pub fn highlight_text<'a>(
1247 self: &'a Arc<Self>,
1248 text: &'a Rope,
1249 range: Range<usize>,
1250 ) -> Vec<(Range<usize>, HighlightId)> {
1251 let mut result = Vec::new();
1252 if let Some(grammar) = &self.grammar {
1253 let tree = grammar.parse_text(text, None);
1254 let captures =
1255 SyntaxSnapshot::single_tree_captures(range.clone(), text, &tree, self, |grammar| {
1256 grammar.highlights_query.as_ref()
1257 });
1258 let highlight_maps = vec![grammar.highlight_map()];
1259 let mut offset = 0;
1260 for chunk in BufferChunks::new(text, range, Some((captures, highlight_maps)), vec![]) {
1261 let end_offset = offset + chunk.text.len();
1262 if let Some(highlight_id) = chunk.syntax_highlight_id {
1263 if !highlight_id.is_default() {
1264 result.push((offset..end_offset, highlight_id));
1265 }
1266 }
1267 offset = end_offset;
1268 }
1269 }
1270 result
1271 }
1272
1273 pub fn path_suffixes(&self) -> &[String] {
1274 &self.config.path_suffixes
1275 }
1276
1277 pub fn should_autoclose_before(&self, c: char) -> bool {
1278 c.is_whitespace() || self.config.autoclose_before.contains(c)
1279 }
1280
1281 pub fn set_theme(&self, theme: &SyntaxTheme) {
1282 if let Some(grammar) = self.grammar.as_ref() {
1283 if let Some(highlights_query) = &grammar.highlights_query {
1284 *grammar.highlight_map.lock() =
1285 HighlightMap::new(highlights_query.capture_names(), theme);
1286 }
1287 }
1288 }
1289
1290 pub fn grammar(&self) -> Option<&Arc<Grammar>> {
1291 self.grammar.as_ref()
1292 }
1293}
1294
1295impl LanguageScope {
1296 pub fn line_comment_prefix(&self) -> Option<&Arc<str>> {
1297 Override::as_option(
1298 self.config_override().map(|o| &o.line_comment),
1299 self.language.config.line_comment.as_ref(),
1300 )
1301 }
1302
1303 pub fn block_comment_delimiters(&self) -> Option<(&Arc<str>, &Arc<str>)> {
1304 Override::as_option(
1305 self.config_override().map(|o| &o.block_comment),
1306 self.language.config.block_comment.as_ref(),
1307 )
1308 .map(|e| (&e.0, &e.1))
1309 }
1310
1311 pub fn brackets(&self) -> impl Iterator<Item = (&BracketPair, bool)> {
1312 let mut disabled_ids = self
1313 .config_override()
1314 .map_or(&[] as _, |o| o.disabled_bracket_ixs.as_slice());
1315 self.language
1316 .config
1317 .brackets
1318 .pairs
1319 .iter()
1320 .enumerate()
1321 .map(move |(ix, bracket)| {
1322 let mut is_enabled = true;
1323 if let Some(next_disabled_ix) = disabled_ids.first() {
1324 if ix == *next_disabled_ix as usize {
1325 disabled_ids = &disabled_ids[1..];
1326 is_enabled = false;
1327 }
1328 }
1329 (bracket, is_enabled)
1330 })
1331 }
1332
1333 pub fn should_autoclose_before(&self, c: char) -> bool {
1334 c.is_whitespace() || self.language.config.autoclose_before.contains(c)
1335 }
1336
1337 fn config_override(&self) -> Option<&LanguageConfigOverride> {
1338 let id = self.override_id?;
1339 let grammar = self.language.grammar.as_ref()?;
1340 let override_config = grammar.override_config.as_ref()?;
1341 override_config.values.get(&id).map(|e| &e.1)
1342 }
1343}
1344
1345impl Hash for Language {
1346 fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
1347 self.id().hash(state)
1348 }
1349}
1350
1351impl PartialEq for Language {
1352 fn eq(&self, other: &Self) -> bool {
1353 self.id().eq(&other.id())
1354 }
1355}
1356
1357impl Eq for Language {}
1358
1359impl Debug for Language {
1360 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1361 f.debug_struct("Language")
1362 .field("name", &self.config.name)
1363 .finish()
1364 }
1365}
1366
1367impl Grammar {
1368 pub fn id(&self) -> usize {
1369 self.id
1370 }
1371
1372 fn parse_text(&self, text: &Rope, old_tree: Option<Tree>) -> Tree {
1373 PARSER.with(|parser| {
1374 let mut parser = parser.borrow_mut();
1375 parser
1376 .set_language(self.ts_language)
1377 .expect("incompatible grammar");
1378 let mut chunks = text.chunks_in_range(0..text.len());
1379 parser
1380 .parse_with(
1381 &mut move |offset, _| {
1382 chunks.seek(offset);
1383 chunks.next().unwrap_or("").as_bytes()
1384 },
1385 old_tree.as_ref(),
1386 )
1387 .unwrap()
1388 })
1389 }
1390
1391 pub fn highlight_map(&self) -> HighlightMap {
1392 self.highlight_map.lock().clone()
1393 }
1394
1395 pub fn highlight_id_for_name(&self, name: &str) -> Option<HighlightId> {
1396 let capture_id = self
1397 .highlights_query
1398 .as_ref()?
1399 .capture_index_for_name(name)?;
1400 Some(self.highlight_map.lock().get(capture_id))
1401 }
1402}
1403
1404impl CodeLabel {
1405 pub fn plain(text: String, filter_text: Option<&str>) -> Self {
1406 let mut result = Self {
1407 runs: Vec::new(),
1408 filter_range: 0..text.len(),
1409 text,
1410 };
1411 if let Some(filter_text) = filter_text {
1412 if let Some(ix) = result.text.find(filter_text) {
1413 result.filter_range = ix..ix + filter_text.len();
1414 }
1415 }
1416 result
1417 }
1418}
1419
1420#[cfg(any(test, feature = "test-support"))]
1421impl Default for FakeLspAdapter {
1422 fn default() -> Self {
1423 Self {
1424 name: "the-fake-language-server",
1425 capabilities: lsp::LanguageServer::full_capabilities(),
1426 initializer: None,
1427 disk_based_diagnostics_progress_token: None,
1428 disk_based_diagnostics_sources: Vec::new(),
1429 }
1430 }
1431}
1432
1433#[cfg(any(test, feature = "test-support"))]
1434#[async_trait]
1435impl LspAdapter for Arc<FakeLspAdapter> {
1436 async fn name(&self) -> LanguageServerName {
1437 LanguageServerName(self.name.into())
1438 }
1439
1440 async fn fetch_latest_server_version(
1441 &self,
1442 _: Arc<dyn HttpClient>,
1443 ) -> Result<Box<dyn 'static + Send + Any>> {
1444 unreachable!();
1445 }
1446
1447 async fn fetch_server_binary(
1448 &self,
1449 _: Box<dyn 'static + Send + Any>,
1450 _: Arc<dyn HttpClient>,
1451 _: PathBuf,
1452 ) -> Result<PathBuf> {
1453 unreachable!();
1454 }
1455
1456 async fn cached_server_binary(&self, _: PathBuf) -> Option<PathBuf> {
1457 unreachable!();
1458 }
1459
1460 async fn process_diagnostics(&self, _: &mut lsp::PublishDiagnosticsParams) {}
1461
1462 async fn disk_based_diagnostic_sources(&self) -> Vec<String> {
1463 self.disk_based_diagnostics_sources.clone()
1464 }
1465
1466 async fn disk_based_diagnostics_progress_token(&self) -> Option<String> {
1467 self.disk_based_diagnostics_progress_token.clone()
1468 }
1469}
1470
1471fn get_capture_indices(query: &Query, captures: &mut [(&str, &mut Option<u32>)]) {
1472 for (ix, name) in query.capture_names().iter().enumerate() {
1473 for (capture_name, index) in captures.iter_mut() {
1474 if capture_name == name {
1475 **index = Some(ix as u32);
1476 break;
1477 }
1478 }
1479 }
1480}
1481
1482pub fn point_to_lsp(point: PointUtf16) -> lsp::Position {
1483 lsp::Position::new(point.row, point.column)
1484}
1485
1486pub fn point_from_lsp(point: lsp::Position) -> Unclipped<PointUtf16> {
1487 Unclipped(PointUtf16::new(point.line, point.character))
1488}
1489
1490pub fn range_to_lsp(range: Range<PointUtf16>) -> lsp::Range {
1491 lsp::Range {
1492 start: point_to_lsp(range.start),
1493 end: point_to_lsp(range.end),
1494 }
1495}
1496
1497pub fn range_from_lsp(range: lsp::Range) -> Range<Unclipped<PointUtf16>> {
1498 let mut start = point_from_lsp(range.start);
1499 let mut end = point_from_lsp(range.end);
1500 if start > end {
1501 mem::swap(&mut start, &mut end);
1502 }
1503 start..end
1504}