4 files changed, 24 insertions, 3 deletions

diff --git a/crates/ra_lsp_server/src/caps.rs b/crates/ra_lsp_server/src/caps.rs
index bca079d65..254624487 100644
--- a/crates/ra_lsp_server/src/caps.rs
+++ b/crates/ra_lsp_server/src/caps.rs
@@ -2,7 +2,7 @@ use lsp_types::{
     CodeActionProviderCapability, CodeLensOptions, CompletionOptions, DocumentOnTypeFormattingOptions,
     ExecuteCommandOptions, FoldingRangeProviderCapability, RenameOptions, RenameProviderCapability,
     ServerCapabilities, SignatureHelpOptions, TextDocumentSyncCapability, TextDocumentSyncKind,
-    TextDocumentSyncOptions,
+    TextDocumentSyncOptions, ImplementationProviderCapability,
 };
 
 pub fn server_capabilities() -> ServerCapabilities {
@@ -26,7 +26,7 @@ pub fn server_capabilities() -> ServerCapabilities {
         }),
         definition_provider: Some(true),
         type_definition_provider: None,
-        implementation_provider: None,
+        implementation_provider: Some(ImplementationProviderCapability::Simple(true)),
         references_provider: Some(true),
         document_highlight_provider: Some(true),
         document_symbol_provider: Some(true),
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index e430ac6de..df390c19e 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -305,6 +305,7 @@ fn on_request(
         .on::<req::DocumentSymbolRequest>(handlers::handle_document_symbol)?
         .on::<req::WorkspaceSymbol>(handlers::handle_workspace_symbol)?
         .on::<req::GotoDefinition>(handlers::handle_goto_definition)?
+        .on::<req::GotoImplementation>(handlers::handle_goto_implementation)?
         .on::<req::ParentModule>(handlers::handle_parent_module)?
         .on::<req::Runnables>(handlers::handle_runnables)?
         .on::<req::DecorationsRequest>(handlers::handle_decorations)?
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index 4f75f9a22..74554f15c 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -229,6 +229,26 @@ pub fn handle_goto_definition(
     Ok(Some(req::GotoDefinitionResponse::Link(res)))
 }
 
+pub fn handle_goto_implementation(
+    world: ServerWorld,
+    params: req::TextDocumentPositionParams,
+) -> Result<Option<req::GotoImplementationResponse>> {
+    let position = params.try_conv_with(&world)?;
+    let line_index = world.analysis().file_line_index(position.file_id);
+    let nav_info = match world.analysis().goto_implementation(position)? {
+        None => return Ok(None),
+        Some(it) => it,
+    };
+    let nav_range = nav_info.range;
+    let res = nav_info
+        .info
+        .into_iter()
+        .map(|nav| RangeInfo::new(nav_range, nav))
+        .map(|nav| to_location_link(&nav, &world, &line_index))
+        .collect::<Result<Vec<_>>>()?;
+    Ok(Some(req::GotoDefinitionResponse::Link(res)))
+}
+
 pub fn handle_parent_module(
     world: ServerWorld,
     params: req::TextDocumentPositionParams,
diff --git a/crates/ra_lsp_server/src/req.rs b/crates/ra_lsp_server/src/req.rs
index a4d890755..e224ede80 100644
--- a/crates/ra_lsp_server/src/req.rs
+++ b/crates/ra_lsp_server/src/req.rs
@@ -8,7 +8,7 @@ pub use lsp_types::{
     CompletionParams, CompletionResponse, DocumentOnTypeFormattingParams, DocumentSymbolParams,
     DocumentSymbolResponse, ExecuteCommandParams, Hover, InitializeResult,
     PublishDiagnosticsParams, ReferenceParams, SignatureHelp, TextDocumentEdit,
-    TextDocumentPositionParams, TextEdit, WorkspaceEdit, WorkspaceSymbolParams,
+    TextDocumentPositionParams, TextEdit, WorkspaceEdit, WorkspaceSymbolParams
 };
 
 pub enum AnalyzerStatus {}