5 files changed, 96 insertions, 22 deletions

diff --git a/crates/ra_lsp_server/src/caps.rs b/crates/ra_lsp_server/src/caps.rs
index 0d02c8073..bcf857fce 100644
--- a/crates/ra_lsp_server/src/caps.rs
+++ b/crates/ra_lsp_server/src/caps.rs
@@ -16,7 +16,7 @@ pub fn server_capabilities() -> ServerCapabilities {
                 save: None,
             },
         )),
-        hover_provider: None,
+        hover_provider: Some(true),
         completion_provider: Some(CompletionOptions {
             resolve_provider: None,
             trigger_characters: None,
diff --git a/crates/ra_lsp_server/src/conv.rs b/crates/ra_lsp_server/src/conv.rs
index fa04f4b00..5d5a0c55e 100644
--- a/crates/ra_lsp_server/src/conv.rs
+++ b/crates/ra_lsp_server/src/conv.rs
@@ -2,7 +2,7 @@ use languageserver_types::{
     Location, Position, Range, SymbolKind, TextDocumentEdit, TextDocumentIdentifier,
     TextDocumentItem, TextDocumentPositionParams, TextEdit, Url, VersionedTextDocumentIdentifier,
 };
-use ra_analysis::{FileId, FileSystemEdit, SourceChange, SourceFileEdit, FilePosition};
+use ra_analysis::{FileId, FileSystemEdit, SourceChange, SourceFileNodeEdit, FilePosition};
 use ra_editor::{AtomEdit, Edit, LineCol, LineIndex};
 use ra_syntax::{SyntaxKind, TextRange, TextUnit};
 
@@ -49,10 +49,9 @@ impl ConvWith for Position {
     type Output = TextUnit;
 
     fn conv_with(self, line_index: &LineIndex) -> TextUnit {
-        // TODO: UTF-16
         let line_col = LineCol {
             line: self.line as u32,
-            col: (self.character as u32).into(),
+            col_utf16: self.character as u32,
         };
         line_index.offset(line_col)
     }
@@ -64,8 +63,10 @@ impl ConvWith for TextUnit {
 
     fn conv_with(self, line_index: &LineIndex) -> Position {
         let line_col = line_index.line_col(self);
-        // TODO: UTF-16
-        Position::new(u64::from(line_col.line), u64::from(u32::from(line_col.col)))
+        Position::new(
+            u64::from(line_col.line),
+            u64::from(u32::from(line_col.col_utf16)),
+        )
     }
 }
 
@@ -203,8 +204,10 @@ impl TryConvWith for SourceChange {
                     .map(|it| it.edits.as_slice())
                     .unwrap_or(&[]);
                 let line_col = translate_offset_with_edit(&*line_index, pos.offset, edits);
-                let position =
-                    Position::new(u64::from(line_col.line), u64::from(u32::from(line_col.col)));
+                let position = Position::new(
+                    u64::from(line_col.line),
+                    u64::from(u32::from(line_col.col_utf16)),
+                );
                 Some(TextDocumentPositionParams {
                     text_document: TextDocumentIdentifier::new(pos.file_id.try_conv_with(world)?),
                     position,
@@ -247,17 +250,17 @@ fn translate_offset_with_edit(
     if in_edit_line_col.line == 0 {
         LineCol {
             line: edit_line_col.line,
-            col: edit_line_col.col + in_edit_line_col.col,
+            col_utf16: edit_line_col.col_utf16 + in_edit_line_col.col_utf16,
         }
     } else {
         LineCol {
             line: edit_line_col.line + in_edit_line_col.line,
-            col: in_edit_line_col.col,
+            col_utf16: in_edit_line_col.col_utf16,
         }
     }
 }
 
-impl TryConvWith for SourceFileEdit {
+impl TryConvWith for SourceFileNodeEdit {
     type Ctx = ServerWorld;
     type Output = TextDocumentEdit;
     fn try_conv_with(self, world: &ServerWorld) -> Result<TextDocumentEdit> {
diff --git a/crates/ra_lsp_server/src/main.rs b/crates/ra_lsp_server/src/main.rs
index c07eb0140..26bcddd8e 100644
--- a/crates/ra_lsp_server/src/main.rs
+++ b/crates/ra_lsp_server/src/main.rs
@@ -2,10 +2,14 @@
 extern crate log;
 #[macro_use]
 extern crate failure;
+#[macro_use]
+extern crate serde_derive;
+extern crate serde;
 extern crate flexi_logger;
 extern crate gen_lsp_server;
 extern crate ra_lsp_server;
 
+use serde::Deserialize;
 use flexi_logger::{Duplicate, Logger};
 use gen_lsp_server::{run_server, stdio_transport};
 use ra_lsp_server::Result;
@@ -30,6 +34,12 @@ fn main() -> Result<()> {
     }
 }
 
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct InitializationOptions {
+    publish_decorations: bool,
+}
+
 fn main_inner() -> Result<()> {
     let (receiver, sender, threads) = stdio_transport();
     let cwd = ::std::env::current_dir()?;
@@ -42,7 +52,12 @@ fn main_inner() -> Result<()> {
                 .root_uri
                 .and_then(|it| it.to_file_path().ok())
                 .unwrap_or(cwd);
-            ra_lsp_server::main_loop(false, root, r, s)
+            let publish_decorations = params
+                .initialization_options
+                .and_then(|v| InitializationOptions::deserialize(v).ok())
+                .map(|it| it.publish_decorations)
+                == Some(true);
+            ra_lsp_server::main_loop(false, root, publish_decorations, r, s)
         },
     )?;
     info!("shutting down IO...");
@@ -50,3 +65,27 @@ fn main_inner() -> Result<()> {
     info!("... IO is down");
     Ok(())
 }
+
+/*
+                    (let ((backend (eglot-xref-backend)))
+                      (mapcar
+                       (lambda (xref)
+                         (let ((loc (xref-item-location xref)))
+                           (propertize
+                            (concat
+                             (when (xref-file-location-p loc)
+                               (with-slots (file line column) loc
+                                 (format "%s:%s:%s:"
+                                         (propertize (file-relative-name file)
+                                                     'face 'compilation-info)
+                                         (propertize (format "%s" line)
+                                                     'face 'compilation-line
+                                                     )
+                                         column)))
+                             (xref-item-summary xref))
+                            'xref xref)))
+                       (xref-backend-apropos backend "Analysis"))
+                      )
+
+
+*/
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index 5314a333e..c872b0dc4 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -4,9 +4,9 @@ use gen_lsp_server::ErrorCode;
 use languageserver_types::{
     CodeActionResponse, Command, CompletionItem, CompletionItemKind, Diagnostic,
     DiagnosticSeverity, DocumentSymbol, Documentation, FoldingRange, FoldingRangeKind,
-    FoldingRangeParams, InsertTextFormat, Location, MarkupContent, MarkupKind, Position,
+    FoldingRangeParams, InsertTextFormat, Location, MarkupContent, MarkupKind, MarkedString, Position,
     PrepareRenameResponse, RenameParams, SymbolInformation, TextDocumentIdentifier, TextEdit,
-    WorkspaceEdit, ParameterInformation, SignatureInformation,
+    WorkspaceEdit, ParameterInformation, SignatureInformation, Hover, HoverContents,
 };
 use ra_analysis::{FileId, FoldKind, Query, RunnableKind, FilePosition};
 use ra_syntax::text_utils::contains_offset_nonstrict;
@@ -478,6 +478,30 @@ pub fn handle_signature_help(
     }
 }
 
+pub fn handle_hover(
+    world: ServerWorld,
+    params: req::TextDocumentPositionParams,
+) -> Result<Option<Hover>> {
+    let position = params.try_conv_with(&world)?;
+    let line_index = world.analysis().file_line_index(position.file_id);
+
+    for (file_id, symbol) in world.analysis().approximately_resolve_symbol(position)? {
+        let range = symbol.node_range.conv_with(&line_index);
+        let comment = world.analysis.doc_comment_for(file_id, symbol)?;
+
+        if comment.is_some() {
+            let contents = HoverContents::Scalar(MarkedString::String(comment.unwrap()));
+
+            return Ok(Some(Hover {
+                contents,
+                range: Some(range),
+            }));
+        }
+    }
+
+    Ok(None)
+}
+
 pub fn handle_prepare_rename(
     world: ServerWorld,
     params: req::TextDocumentPositionParams,
diff --git a/crates/ra_lsp_server/src/main_loop/mod.rs b/crates/ra_lsp_server/src/main_loop/mod.rs
index 229d1b0f7..78d93741a 100644
--- a/crates/ra_lsp_server/src/main_loop/mod.rs
+++ b/crates/ra_lsp_server/src/main_loop/mod.rs
@@ -48,6 +48,7 @@ enum Task {
 pub fn main_loop(
     internal_mode: bool,
     root: PathBuf,
+    publish_decorations: bool,
     msg_receiver: &Receiver<RawMessage>,
     msg_sender: &Sender<RawMessage>,
 ) -> Result<()> {
@@ -67,6 +68,7 @@ pub fn main_loop(
     let mut subs = Subscriptions::new();
     let main_res = main_loop_inner(
         internal_mode,
+        publish_decorations,
         root,
         &pool,
         msg_sender,
@@ -99,6 +101,7 @@ pub fn main_loop(
 
 fn main_loop_inner(
     internal_mode: bool,
+    publish_decorations: bool,
     ws_root: PathBuf,
     pool: &ThreadPool,
     msg_sender: &Sender<RawMessage>,
@@ -210,6 +213,7 @@ fn main_loop_inner(
             update_file_notifications_on_threadpool(
                 pool,
                 state.snapshot(),
+                publish_decorations,
                 task_sender.clone(),
                 subs.subscriptions(),
             )
@@ -259,6 +263,7 @@ fn on_request(
         .on::<req::CodeActionRequest>(handlers::handle_code_action)?
         .on::<req::FoldingRangeRequest>(handlers::handle_folding_range)?
         .on::<req::SignatureHelpRequest>(handlers::handle_signature_help)?
+        .on::<req::HoverRequest>(handlers::handle_hover)?
         .on::<req::PrepareRenameRequest>(handlers::handle_prepare_rename)?
         .on::<req::Rename>(handlers::handle_rename)?
         .on::<req::References>(handlers::handle_references)?
@@ -415,6 +420,7 @@ impl<'a> PoolDispatcher<'a> {
 fn update_file_notifications_on_threadpool(
     pool: &ThreadPool,
     world: ServerWorld,
+    publish_decorations: bool,
     sender: Sender<Task>,
     subscriptions: Vec<FileId>,
 ) {
@@ -431,15 +437,17 @@ fn update_file_notifications_on_threadpool(
                     sender.send(Task::Notify(not));
                 }
             }
-            match handlers::publish_decorations(&world, file_id) {
-                Err(e) => {
-                    if !is_canceled(&e) {
-                        error!("failed to compute decorations: {:?}", e);
+            if publish_decorations {
+                match handlers::publish_decorations(&world, file_id) {
+                    Err(e) => {
+                        if !is_canceled(&e) {
+                            error!("failed to compute decorations: {:?}", e);
+                        }
+                    }
+                    Ok(params) => {
+                        let not = RawNotification::new::<req::PublishDecorations>(&params);
+                        sender.send(Task::Notify(not))
                     }
-                }
-                Ok(params) => {
-                    let not = RawNotification::new::<req::PublishDecorations>(&params);
-                    sender.send(Task::Notify(not))
                 }
             }
         }