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- /*jshint node:true */
- /*
- The MIT License (MIT)
- Copyright (c) 2007-2018 Einar Lielmanis, Liam Newman, and contributors.
- Permission is hereby granted, free of charge, to any person
- obtaining a copy of this software and associated documentation files
- (the "Software"), to deal in the Software without restriction,
- including without limitation the rights to use, copy, modify, merge,
- publish, distribute, sublicense, and/or sell copies of the Software,
- and to permit persons to whom the Software is furnished to do so,
- subject to the following conditions:
- The above copyright notice and this permission notice shall be
- included in all copies or substantial portions of the Software.
- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
- BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
- ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- SOFTWARE.
- */
- 'use strict';
- function TokenStream(parent_token) {
- // private
- this.__tokens = [];
- this.__tokens_length = this.__tokens.length;
- this.__position = 0;
- this.__parent_token = parent_token;
- }
- TokenStream.prototype.restart = function() {
- this.__position = 0;
- };
- TokenStream.prototype.isEmpty = function() {
- return this.__tokens_length === 0;
- };
- TokenStream.prototype.hasNext = function() {
- return this.__position < this.__tokens_length;
- };
- TokenStream.prototype.next = function() {
- var val = null;
- if (this.hasNext()) {
- val = this.__tokens[this.__position];
- this.__position += 1;
- }
- return val;
- };
- TokenStream.prototype.peek = function(index) {
- var val = null;
- index = index || 0;
- index += this.__position;
- if (index >= 0 && index < this.__tokens_length) {
- val = this.__tokens[index];
- }
- return val;
- };
- TokenStream.prototype.add = function(token) {
- if (this.__parent_token) {
- token.parent = this.__parent_token;
- }
- this.__tokens.push(token);
- this.__tokens_length += 1;
- };
- module.exports.TokenStream = TokenStream;
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