match lezer API

src/index.ts

@@ -100,7 +100,7 @@ export function parseFile(path: string, globals?: Record<string, any>): SyntaxNo
     return parseCode(code, globals)
 }
 
-export function parseCode(code: string, globals?: Record<string, any>): SyntaxNode {
+export function parseCode(code: string, globals?: Record<string, any>): Tree {
     const oldGlobals = [...parserGlobals]
     const globalNames = [...Object.keys(prelude), ...(globals ? Object.keys(globals) : [])]
 
@@ -108,5 +108,5 @@ export function parseCode(code: string, globals?: Record<string, any>): SyntaxNo
     const result = parse(code)
     setParserGlobals(oldGlobals)
 
-    return result
+    return new Tree(result)
 }

src/parser/node.ts

@@ -114,6 +114,19 @@ export const operators: Record<string, any> = {
 
 export class Tree {
   constructor(public topNode: SyntaxNode) { }
+
+  get length(): number {
+    return this.topNode.to
+  }
+
+  cursor() {
+    return {
+      type: this.topNode.type,
+      from: this.topNode.from,
+      to: this.topNode.to,
+      node: this.topNode,
+    }
+  }
 }
 
 // TODO: TEMPORARY SHIM