Configure language servers via LanguageConfiguration.

helix-core/src/syntax.rs

@@ -11,20 +11,27 @@
 
 // largely based on tree-sitter/cli/src/loader.rs
 pub struct LanguageConfiguration {
-    pub(crate) scope: String,           // source.rust
-    pub(crate) file_types: Vec<String>, // filename ends_with? <Gemfile, rb, etc>
+    pub scope: String,           // source.rust
+    pub file_types: Vec<String>, // filename ends_with? <Gemfile, rb, etc>
+    pub roots: Vec<String>,      // these indicate project roots <.git, Cargo.toml>
 
-    pub(crate) path: PathBuf,
+    pub path: PathBuf,
+    // root_path for tree-sitter (^)
 
     // content_regex
     // injection_regex
     // first_line_regex
     //
-    // root_path
     //
     pub(crate) language_id: Lang,
     pub(crate) highlight_config: OnceCell<Option<Arc<HighlightConfiguration>>>,
     // tags_config OnceCell<> https://github.com/tree-sitter/tree-sitter/pull/583
+    pub language_server_config: Option<LanguageServerConfiguration>,
+}
+
+pub struct LanguageServerConfiguration {
+    pub command: String,
+    pub args: Vec<String>,
 }
 
 impl LanguageConfiguration {
@@ -90,6 +97,11 @@ fn init() -> Loader {
                 highlight_config: OnceCell::new(),
                 //
                 path: "../helix-syntax/languages/tree-sitter-rust".into(),
+                roots: vec![],
+                language_server_config: Some(LanguageServerConfiguration {
+                    command: "rust-analyzer".to_string(),
+                    args: vec![],
+                }),
             },
             LanguageConfiguration {
                 scope: "source.toml".to_string(),
@@ -98,6 +110,8 @@ fn init() -> Loader {
                 highlight_config: OnceCell::new(),
                 //
                 path: "../helix-syntax/languages/tree-sitter-toml".into(),
+                roots: vec![],
+                language_server_config: None,
             },
         ];
 

helix-lsp/src/lib.rs

@@ -10,6 +10,8 @@
 pub use client::Client;
 pub use lsp::{Position, Url};
 
+use helix_core::syntax::LanguageConfiguration;
+
 use thiserror::Error;
 
 use std::{collections::HashMap, sync::Arc};
@@ -106,7 +108,7 @@ pub fn parse(method: &str, params: jsonrpc::Params) -> Notification {
 use smol::channel::Receiver;
 
 pub struct Registry {
-    inner: HashMap<LanguageId, OnceCell<Arc<Client>>>,
+    inner: HashMap<LanguageId, Arc<Client>>,
 
     pub incoming: SelectAll<Receiver<Call>>,
 }
@@ -119,35 +121,43 @@ fn default() -> Self {
 
 impl Registry {
     pub fn new() -> Self {
-        let mut inner = HashMap::new();
-
-        inner.insert("source.rust".to_string(), OnceCell::new());
-
         Self {
-            inner,
+            inner: HashMap::new(),
             incoming: SelectAll::new(),
         }
     }
 
-    pub fn get(&self, id: &str, ex: &smol::Executor) -> Option<Arc<Client>> {
-        // TODO: use get_or_try_init and propagate the error
-        self.inner
-            .get(id)
-            .map(|cell| {
-                cell.get_or_init(|| {
+    pub fn get(
+        &mut self,
+        language_config: &LanguageConfiguration,
+        ex: &smol::Executor,
+    ) -> Option<Arc<Client>> {
+        // TODO: propagate the error
+        if let Some(config) = &language_config.language_server_config {
+            // avoid borrow issues
+            let inner = &mut self.inner;
+            let s_incoming = &self.incoming;
+
+            let language_server = inner
+                .entry(language_config.scope.clone()) // can't use entry with Borrow keys: https://github.com/rust-lang/rfcs/pull/1769
+                .or_insert_with(|| {
                     // TODO: lookup defaults for id (name, args)
 
                     // initialize a new client
-                    let (mut client, incoming) = Client::start(&ex, "rust-analyzer", &[]);
+                    let (mut client, incoming) = Client::start(&ex, &config.command, &config.args);
                     // TODO: run this async without blocking
                     smol::block_on(client.initialize()).unwrap();
 
-                    self.incoming.push(incoming);
+                    s_incoming.push(incoming);
 
                     Arc::new(client)
                 })
-            })
-            .cloned()
+                .clone();
+
+            return Some(language_server);
+        }
+
+        None
     }
 }
 

helix-view/src/document.rs

@@ -4,7 +4,8 @@
 use std::sync::Arc;
 
 use helix_core::{
-    syntax::LOADER, ChangeSet, Diagnostic, History, Rope, Selection, State, Syntax, Transaction,
+    syntax::{LanguageConfiguration, LOADER},
+    ChangeSet, Diagnostic, History, Rope, Selection, State, Syntax, Transaction,
 };
 
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
@@ -26,8 +27,8 @@ pub struct Document {
 
     /// Tree-sitter AST tree
     pub syntax: Option<Syntax>,
-    /// Corresponding language scope name. Usually `source.<lang>`.
-    language: Option<String>,
+    // /// Corresponding language scope name. Usually `source.<lang>`.
+    pub(crate) language: Option<Arc<LanguageConfiguration>>,
 
     /// Pending changes since last history commit.
     changes: ChangeSet,
@@ -144,20 +145,13 @@ pub fn set_language(
         scopes: &[String],
     ) {
         if let Some(language_config) = language_config {
-            // TODO: maybe just keep an Arc<> pointer to the language_config?
-            self.language = Some(language_config.scope().to_string());
+            if let Some(highlight_config) = language_config.highlight_config(scopes) {
+                let syntax = Syntax::new(&self.state.doc, highlight_config);
+                self.syntax = Some(syntax);
+                // TODO: config.configure(scopes) is now delayed, is that ok?
+            }
 
-            // TODO: this ties lsp support to tree-sitter enabled languages for now. Language
-            // config should use Option<HighlightConfig> to let us have non-tree-sitter configs.
-
-            let highlight_config = language_config
-                .highlight_config(scopes)
-                .expect("No highlight_config found!");
-            // TODO: config.configure(scopes) is now delayed, is that ok?
-
-            let syntax = Syntax::new(&self.state.doc, highlight_config);
-
-            self.syntax = Some(syntax);
+            self.language = Some(language_config);
         } else {
             self.syntax = None;
             self.language = None;
@@ -286,7 +280,9 @@ pub fn mode(&self) -> Mode {
     #[inline]
     /// Corresponding language scope name. Usually `source.<lang>`.
     pub fn language(&self) -> Option<&str> {
-        self.language.as_deref()
+        self.language
+            .as_ref()
+            .map(|language| language.scope.as_str())
     }
 
     #[inline]

helix-view/src/editor.rs

@@ -39,7 +39,8 @@ pub fn open(&mut self, path: PathBuf, executor: &smol::Executor) -> Result<(), E
 
         // try to find a language server based on the language name
         let language_server = doc
-            .language()
+            .language
+            .as_ref()
             .and_then(|language| self.language_servers.get(language, &executor));
 
         if let Some(language_server) = language_server {