Add select-{larger,smaller}-syntax-node commands

keymaps/darwin.cson

@@ -161,6 +161,8 @@
   'ctrl-alt-shift-right': 'editor:select-to-next-subword-boundary'
   'ctrl-alt-backspace': 'editor:delete-to-beginning-of-subword'
   'ctrl-alt-delete': 'editor:delete-to-end-of-subword'
+  'ctrl-alt-up': 'editor:select-larger-syntax-node'
+  'ctrl-alt-down': 'editor:select-smaller-syntax-node'
 
 'atom-workspace atom-text-editor:not([mini])':
   # Atom specific

src/register-default-commands.coffee

@@ -160,6 +160,8 @@ module.exports = ({commandRegistry, commandInstaller, config, notificationManage
       'editor:select-to-previous-subword-boundary': -> @selectToPreviousSubwordBoundary()
       'editor:select-to-first-character-of-line': -> @selectToFirstCharacterOfLine()
       'editor:select-line': -> @selectLinesContainingCursors()
+      'editor:select-larger-syntax-node': -> @selectLargerSyntaxNode()
+      'editor:select-smaller-syntax-node': -> @selectSmallerSyntaxNode()
     }),
     false
   )

src/text-editor.js

@@ -3053,13 +3053,33 @@ class TextEditor {
     return this.expandSelectionsBackward(selection => selection.selectToBeginningOfPreviousParagraph())
   }
 
+  // Extended: For each selection, select the syntax node that contains
+  // that selection.
   selectLargerSyntaxNode () {
     const languageMode = this.buffer.getLanguageMode()
     if (!languageMode.getRangeForSyntaxNodeContainingRange) return
 
     this.expandSelectionsForward(selection => {
-      const range = languageMode.getRangeForSyntaxNodeContainingRange(selection.getBufferRange())
-      if (range) selection.setBufferRange(range)
+      const currentRange = selection.getBufferRange()
+      const newRange = languageMode.getRangeForSyntaxNodeContainingRange(currentRange)
+      if (newRange) {
+        if (!selection._rangeStack) selection._rangeStack = []
+        selection._rangeStack.push(currentRange)
+        selection.setBufferRange(newRange)
+      }
+    })
+  }
+
+  // Extended: Undo the effect a preceding call to {::selectLargerSyntaxNode}.
+  selectSmallerSyntaxNode () {
+    this.expandSelectionsForward(selection => {
+      if (selection._rangeStack) {
+        const lastRange = selection._rangeStack[selection._rangeStack.length - 1]
+        if (lastRange && selection.getBufferRange().containsRange(lastRange)) {
+          selection._rangeStack.length--
+          selection.setBufferRange(lastRange)
+        }
+      }
     })
   }
 

src/tree-sitter-language-mode.js

@@ -220,6 +220,20 @@ class TreeSitterLanguageMode {
     }
   }
 
+  /*
+   * Syntax Tree APIs
+   */
+
+  getRangeForSyntaxNodeContainingRange (range) {
+    const startIndex = this.buffer.characterIndexForPosition(range.start)
+    const endIndex = this.buffer.characterIndexForPosition(range.end)
+    let node = this.document.rootNode.descendantForIndex(startIndex, endIndex - 1)
+    while (node && node.startIndex === startIndex && node.endIndex === endIndex) {
+      node = node.parent
+    }
+    if (node) return new Range(node.startPosition, node.endPosition)
+  }
+
   /*
    * Section - Backward compatibility shims
    */