Merge #167

167: Attempt to extract useful comments from function signatures r=matklad a=kjeremy

I'm trying to extract useful function comments for signature info. This will also be useful for hover.  This is a WIP (and actually works pretty well!) but I don't think it's the right approach long term so some guidance would be appreciated so that we could also get comments for say types and variable instances etc.

Currently `test_fn_signature_with_simple_doc` fails due to a bug in `extend` but we probably shouldn't use this approach anyway. Maybe comments should be attached to nodes somehow? I'm also thinking that maybe the markdown bits should live in the language server.

Thoughts?

Co-authored-by: Jeremy A. Kolb <[email protected]>

1 files changed, 11 insertions, 2 deletions

diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index 4ac08e527..20cb5f772 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -5,7 +5,7 @@ use languageserver_types::{
     CodeActionResponse, Command, CompletionItem, CompletionItemKind, Diagnostic,
     DiagnosticSeverity, DocumentSymbol, FoldingRange, FoldingRangeKind, FoldingRangeParams,
     InsertTextFormat, Location, Position, SymbolInformation, TextDocumentIdentifier, TextEdit,
-    RenameParams, WorkspaceEdit, PrepareRenameResponse
+    RenameParams, WorkspaceEdit, PrepareRenameResponse, Documentation, MarkupContent, MarkupKind
 };
 use gen_lsp_server::ErrorCode;
 use ra_analysis::{FileId, FoldKind, Query, RunnableKind};
@@ -465,9 +465,18 @@ pub fn handle_signature_help(
             })
             .collect();
 
+        let documentation = if let Some(doc) = descriptor.doc {
+            Some(Documentation::MarkupContent(MarkupContent {
+                kind: MarkupKind::Markdown,
+                value: doc
+            }))
+        } else {
+            None
+        };
+
         let sig_info = SignatureInformation {
             label: descriptor.label,
-            documentation: None,
+            documentation,
             parameters: Some(parameters),
         };