4 files changed, 71 insertions, 2 deletions

diff --git a/crates/ra_lsp_server/src/caps.rs b/crates/ra_lsp_server/src/caps.rs
index 2af2b89fe..f6d2b75e7 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, ImplementationProviderCapability,
+    TextDocumentSyncOptions, ImplementationProviderCapability, GenericCapability,
 };
 
 pub fn server_capabilities() -> ServerCapabilities {
@@ -37,6 +37,7 @@ pub fn server_capabilities() -> ServerCapabilities {
             first_trigger_character: "=".to_string(),
             more_trigger_character: Some(vec![".".to_string()]),
         }),
+        selection_range_provider: Some(GenericCapability::default()),
         folding_range_provider: Some(FoldingRangeProviderCapability::Simple(true)),
         rename_provider: Some(RenameProviderCapability::Options(RenameOptions {
             prepare_provider: Some(true),
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index 07ac4917a..dc1f8f3f7 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -297,6 +297,7 @@ fn on_request(
         .on::<req::AnalyzerStatus>(handlers::handle_analyzer_status)?
         .on::<req::SyntaxTree>(handlers::handle_syntax_tree)?
         .on::<req::ExtendSelection>(handlers::handle_extend_selection)?
+        .on::<req::SelectionRangeRequest>(handlers::handle_selection_range)?
         .on::<req::FindMatchingBrace>(handlers::handle_find_matching_brace)?
         .on::<req::JoinLines>(handlers::handle_join_lines)?
         .on::<req::OnEnter>(handlers::handle_on_enter)?
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index eb8a53545..530081494 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -11,7 +11,7 @@ use ra_ide_api::{
     FileId, FilePosition, FileRange, FoldKind, Query, RangeInfo, RunnableKind, Severity, Cancelable,
     AssistId,
 };
-use ra_syntax::{AstNode, SyntaxKind, TextUnit};
+use ra_syntax::{AstNode, SyntaxKind, TextUnit, TextRange};
 use ra_prof::profile;
 use rustc_hash::FxHashMap;
 use serde::{Serialize, Deserialize};
@@ -39,10 +39,15 @@ pub fn handle_syntax_tree(world: ServerWorld, params: req::SyntaxTreeParams) ->
     Ok(res)
 }
 
+// FIXME: drop this API
 pub fn handle_extend_selection(
     world: ServerWorld,
     params: req::ExtendSelectionParams,
 ) -> Result<req::ExtendSelectionResult> {
+    log::error!(
+        "extend selection is deprecated and will be removed soon,
+         use the new selection range API in LSP",
+    );
     let file_id = params.text_document.try_conv_with(&world)?;
     let line_index = world.analysis().file_line_index(file_id);
     let selections = params
@@ -55,6 +60,46 @@ pub fn handle_extend_selection(
     Ok(req::ExtendSelectionResult { selections })
 }
 
+pub fn handle_selection_range(
+    world: ServerWorld,
+    params: req::SelectionRangeParams,
+) -> Result<Vec<req::SelectionRange>> {
+    let file_id = params.text_document.try_conv_with(&world)?;
+    let line_index = world.analysis().file_line_index(file_id);
+    params
+        .positions
+        .into_iter()
+        .map_conv_with(&line_index)
+        .map(|position| {
+            let mut ranges = Vec::new();
+            {
+                let mut range = TextRange::from_to(position, position);
+                loop {
+                    ranges.push(range);
+                    let frange = FileRange { file_id, range };
+                    let next = world.analysis().extend_selection(frange)?;
+                    if next == range {
+                        break;
+                    } else {
+                        range = next
+                    }
+                }
+            }
+            let mut range = req::SelectionRange {
+                range: ranges.last().unwrap().conv_with(&line_index),
+                parent: None,
+            };
+            for r in ranges.iter().rev().skip(1) {
+                range = req::SelectionRange {
+                    range: r.conv_with(&line_index),
+                    parent: Some(Box::new(range)),
+                }
+            }
+            Ok(range)
+        })
+        .collect()
+}
+
 pub fn handle_find_matching_brace(
     world: ServerWorld,
     params: req::FindMatchingBraceParams,
diff --git a/crates/ra_lsp_server/src/req.rs b/crates/ra_lsp_server/src/req.rs
index 4f35ab9b5..6090eb7b9 100644
--- a/crates/ra_lsp_server/src/req.rs
+++ b/crates/ra_lsp_server/src/req.rs
@@ -64,6 +64,28 @@ pub struct ExtendSelectionResult {
     pub selections: Vec<Range>,
 }
 
+pub enum SelectionRangeRequest {}
+
+impl Request for SelectionRangeRequest {
+    type Params = SelectionRangeParams;
+    type Result = Vec<SelectionRange>;
+    const METHOD: &'static str = "textDocument/selectionRange";
+}
+
+#[derive(Deserialize, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct SelectionRangeParams {
+    pub text_document: TextDocumentIdentifier,
+    pub positions: Vec<Position>,
+}
+
+#[derive(Serialize, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct SelectionRange {
+    pub range: Range,
+    pub parent: Option<Box<SelectionRange>>,
+}
+
 pub enum FindMatchingBrace {}
 
 impl Request for FindMatchingBrace {