3 files changed, 24 insertions, 27 deletions

diff --git a/crates/ra_ide_api/src/extend_selection.rs b/crates/ra_ide_api/src/extend_selection.rs
index 9f0ab2f1c..718b4def5 100644
--- a/crates/ra_ide_api/src/extend_selection.rs
+++ b/crates/ra_ide_api/src/extend_selection.rs
@@ -51,7 +51,7 @@ mod tests {
             }
         ",
         );
-        let r = analysis.extend_selection(frange);
+        let r = analysis.extend_selection(frange).unwrap();
         assert_eq!(r, TextRange::from_to(51.into(), 56.into()));
     }
 }
diff --git a/crates/ra_ide_api/src/lib.rs b/crates/ra_ide_api/src/lib.rs
index 33bef178a..919d248e2 100644
--- a/crates/ra_ide_api/src/lib.rs
+++ b/crates/ra_ide_api/src/lib.rs
@@ -299,7 +299,7 @@ impl Analysis {
     }
 
     /// Gets the syntax tree of the file.
-    pub fn file_syntax(&self, file_id: FileId) -> TreeArc<SourceFile> {
+    pub fn parse(&self, file_id: FileId) -> TreeArc<SourceFile> {
         self.db.source_file(file_id).clone()
     }
 
@@ -310,14 +310,15 @@ impl Analysis {
     }
 
     /// Selects the next syntactic nodes encopasing the range.
-    pub fn extend_selection(&self, frange: FileRange) -> TextRange {
-        extend_selection::extend_selection(&self.db, frange)
+    pub fn extend_selection(&self, frange: FileRange) -> Cancelable<TextRange> {
+        self.with_db(|db| extend_selection::extend_selection(db, frange))
     }
 
     /// Returns position of the mathcing brace (all types of braces are
     /// supported).
-    pub fn matching_brace(&self, file: &SourceFile, offset: TextUnit) -> Option<TextUnit> {
-        ra_ide_api_light::matching_brace(file, offset)
+    pub fn matching_brace(&self, position: FilePosition) -> Option<TextUnit> {
+        let file = self.db.source_file(position.file_id);
+        ra_ide_api_light::matching_brace(&file, position.offset)
     }
 
     /// Returns a syntax tree represented as `String`, for debug purposes.
@@ -388,8 +389,7 @@ impl Analysis {
         &self,
         position: FilePosition,
     ) -> Cancelable<Option<RangeInfo<Vec<NavigationTarget>>>> {
-        self.db
-            .catch_canceled(|db| goto_definition::goto_definition(db, position))
+        self.with_db(|db| goto_definition::goto_definition(db, position))
     }
 
     /// Finds all usages of the reference at point.
@@ -404,8 +404,7 @@ impl Analysis {
 
     /// Computes parameter information for the given call expression.
     pub fn call_info(&self, position: FilePosition) -> Cancelable<Option<CallInfo>> {
-        self.db
-            .catch_canceled(|db| call_info::call_info(db, position))
+        self.with_db(|db| call_info::call_info(db, position))
     }
 
     /// Returns a `mod name;` declaration which created the current module.
@@ -420,33 +419,28 @@ impl Analysis {
 
     /// Returns the root file of the given crate.
     pub fn crate_root(&self, crate_id: CrateId) -> Cancelable<FileId> {
-        Ok(self.db.crate_graph().crate_root(crate_id))
+        self.with_db(|db| db.crate_graph().crate_root(crate_id))
     }
 
     /// Returns the set of possible targets to run for the current file.
     pub fn runnables(&self, file_id: FileId) -> Cancelable<Vec<Runnable>> {
-        self.db
-            .catch_canceled(|db| runnables::runnables(db, file_id))
+        self.with_db(|db| runnables::runnables(db, file_id))
     }
 
     /// Computes syntax highlighting for the given file.
     pub fn highlight(&self, file_id: FileId) -> Cancelable<Vec<HighlightedRange>> {
-        self.db
-            .catch_canceled(|db| syntax_highlighting::highlight(db, file_id))
+        self.with_db(|db| syntax_highlighting::highlight(db, file_id))
     }
 
     /// Computes completions at the given position.
     pub fn completions(&self, position: FilePosition) -> Cancelable<Option<Vec<CompletionItem>>> {
-        let completions = self
-            .db
-            .catch_canceled(|db| completion::completions(db, position))?;
-        Ok(completions.map(|it| it.into()))
+        self.with_db(|db| completion::completions(db, position).map(Into::into))
     }
 
     /// Computes assists (aks code actons aka intentions) for the given
     /// position.
     pub fn assists(&self, frange: FileRange) -> Cancelable<Vec<SourceChange>> {
-        Ok(self.db.assists(frange))
+        self.with_db(|db| db.assists(frange))
     }
 
     /// Computes the set of diagnostics for the given file.
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index 8f9db68a2..02393f728 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -8,7 +8,7 @@ use lsp_types::{
     WorkspaceEdit
 };
 use ra_ide_api::{
-    FileId, FilePosition, FileRange, FoldKind, Query, RangeInfo, RunnableKind, Severity,
+    FileId, FilePosition, FileRange, FoldKind, Query, RangeInfo, RunnableKind, Severity, Cancelable,
 };
 use ra_syntax::{AstNode, TextUnit};
 use rustc_hash::FxHashMap;
@@ -40,9 +40,13 @@ pub fn handle_extend_selection(
         .into_iter()
         .map_conv_with(&line_index)
         .map(|range| FileRange { file_id, range })
-        .map(|frange| world.analysis().extend_selection(frange))
-        .map_conv_with(&line_index)
-        .collect();
+        .map(|frange| {
+            world
+                .analysis()
+                .extend_selection(frange)
+                .map(|it| it.conv_with(&line_index))
+        })
+        .collect::<Cancelable<Vec<_>>>()?;
     Ok(req::ExtendSelectionResult { selections })
 }
 
@@ -51,7 +55,6 @@ pub fn handle_find_matching_brace(
     params: req::FindMatchingBraceParams,
 ) -> Result<Vec<Position>> {
     let file_id = params.text_document.try_conv_with(&world)?;
-    let file = world.analysis().file_syntax(file_id);
     let line_index = world.analysis().file_line_index(file_id);
     let res = params
         .offsets
@@ -60,7 +63,7 @@ pub fn handle_find_matching_brace(
         .map(|offset| {
             world
                 .analysis()
-                .matching_brace(&file, offset)
+                .matching_brace(FilePosition { file_id, offset })
                 .unwrap_or(offset)
         })
         .map_conv_with(&line_index)
@@ -315,7 +318,7 @@ pub fn handle_completion(
         let mut res = false;
         if let Some(ctx) = params.context {
             if ctx.trigger_character.unwrap_or_default() == ":" {
-                let source_file = world.analysis().file_syntax(position.file_id);
+                let source_file = world.analysis().parse(position.file_id);
                 let syntax = source_file.syntax();
                 let text = syntax.text();
                 if let Some(next_char) = text.char_at(position.offset) {