3 files changed, 50 insertions, 3 deletions

diff --git a/code/native/src/lib.rs b/code/native/src/lib.rs
index aae7ad2f3..cb304a141 100644
--- a/code/native/src/lib.rs
+++ b/code/native/src/lib.rs
@@ -3,6 +3,7 @@ extern crate neon;
 extern crate libeditor;
 
 use neon::prelude::*;
+use libeditor::TextRange;
 
 pub struct Wrapper {
     inner: libeditor::File,
@@ -19,8 +20,8 @@ declare_types! {
         }
 
         method syntaxTree(mut cx) {
-            let this = cx.this();
             let tree = {
+            let this = cx.this();
                 let guard = cx.lock();
                 let wrapper = this.borrow(&guard);
                 wrapper.inner.syntax_tree()
@@ -29,8 +30,8 @@ declare_types! {
         }
 
         method highlight(mut cx) {
-            let this = cx.this();
             let highlights = {
+                let this = cx.this();
                 let guard = cx.lock();
                 let wrapper = this.borrow(&guard);
                 wrapper.inner.highlight()
@@ -51,6 +52,33 @@ declare_types! {
 
             Ok(res.upcast())
         }
+
+        method extendSelection(mut cx) {
+            let from_offset = cx.argument::<JsNumber>(0)?.value() as u32;
+            let to_offset = cx.argument::<JsNumber>(1)?.value() as u32;
+            let text_range = TextRange::from_to(from_offset.into(), to_offset.into());
+            let extended_range = {
+                let this = cx.this();
+                let guard = cx.lock();
+                let wrapper = this.borrow(&guard);
+                wrapper.inner.extend_selection(text_range)
+            };
+
+            match extended_range {
+                None => Ok(cx.null().upcast()),
+                Some(range) => {
+                    let start: u32 = range.start().into();
+                    let end: u32 = range.end().into();
+                    let start = cx.number(start);
+                    let end = cx.number(end);
+                    let arr = cx.empty_array();
+                    arr.set(&mut cx, 0, start)?;
+                    arr.set(&mut cx, 1, end)?;
+                    Ok(arr.upcast())
+                }
+            }
+
+        }
     }
 
 }
diff --git a/code/package.json b/code/package.json
index 2f97bb5c0..66c4f266f 100644
--- a/code/package.json
+++ b/code/package.json
@@ -36,11 +36,15 @@
             {
                 "command": "libsyntax-rust.syntaxTree",
                 "title": "Show Rust syntax tree"
+            },
+            {
+                "command": "libsyntax-rust.extendSelection",
+                "title": "Rust Extend Selection"
             }
         ],
         "keybindings": [
             {
-                "command": "libsyntax-rust.semanticSelection",
+                "command": "libsyntax-rust.extendSelection",
                 "key": "ctrl+w",
                 "when": "editorTextFocus && editorLangId == rust"
             }
diff --git a/code/src/main.ts b/code/src/main.ts
index 75a824b7b..72bef7061 100644
--- a/code/src/main.ts
+++ b/code/src/main.ts
@@ -34,6 +34,16 @@ export function activate(context: vscode.ExtensionContext) {
     ))
 
     registerCommand('libsyntax-rust.syntaxTree', () => openDoc(uris.syntaxTree))
+    registerCommand('libsyntax-rust.extendSelection', () => {
+        let editor = vscode.window.activeTextEditor
+        let file = activeSyntax()
+        if (editor == null || file == null) return
+        editor.selections = editor.selections.map((s) => {
+            let range = file.extendSelection(s)
+            if (range == null) return null
+            return new vscode.Selection(range.start, range.end)
+        })
+    })
 }
 
 export function deactivate() { }
@@ -49,6 +59,11 @@ export class Syntax {
 
     syntaxTree(): string { return this.imp.syntaxTree() }
     highlight(): Array<[number, number, string]> { return this.imp.highlight() }
+    extendSelection(range: vscode.Range): vscode.Range {
+        let range_ = fromVsRange(this.doc, range);
+        let extRange = this.imp.extendSelection(range_[0], range_[1]);
+        return toVsRange(this.doc, extRange);
+    }
 }