[token] make parent and source non-enumerable

src/index.js

@@ -87,8 +87,6 @@ class Token {
  Object.assign(this, options);
  this.type_id = type;
  this.type = NAMES[type];
- this.parent = undefined;
- this.source = undefined;
  this.children = [];
 
  this.start = start;
@@ -98,6 +96,22 @@ class Token {
  this.closing = undefined; // Used by TAG_CONTROL to indicate a closing tag
  this.value = undefined; // Used to store parsed values of expressions.
  this.expr = undefined; // Used to hold the specific expressions on EXPRESSION node.
+
+ Object.defineProperty(this, 'source', {
+ value: undefined,
+ enumerable: false,
+ writable: true
+ });
+
+ Object.defineProperty(this, 'parent', {
+ value: undefined,
+ enumerable: false,
+ writable: true
+ });
+ }
+
+ get match() {
+ return this.source.substr(this.start, this.end - this.start + 1);
  }
 
  is(type) {