| var SyntaxError = require('./SyntaxError'); |
| |
| var TAB = 9; |
| var N = 10; |
| var F = 12; |
| var R = 13; |
| var SPACE = 32; |
| |
| var Tokenizer = function(str) { |
| this.str = str; |
| this.pos = 0; |
| }; |
| |
| Tokenizer.prototype = { |
| charCodeAt: function(pos) { |
| return pos < this.str.length ? this.str.charCodeAt(pos) : 0; |
| }, |
| charCode: function() { |
| return this.charCodeAt(this.pos); |
| }, |
| nextCharCode: function() { |
| return this.charCodeAt(this.pos + 1); |
| }, |
| nextNonWsCode: function(pos) { |
| return this.charCodeAt(this.findWsEnd(pos)); |
| }, |
| findWsEnd: function(pos) { |
| for (; pos < this.str.length; pos++) { |
| var code = this.str.charCodeAt(pos); |
| if (code !== R && code !== N && code !== F && code !== SPACE && code !== TAB) { |
| break; |
| } |
| } |
| |
| return pos; |
| }, |
| substringToPos: function(end) { |
| return this.str.substring(this.pos, this.pos = end); |
| }, |
| eat: function(code) { |
| if (this.charCode() !== code) { |
| this.error('Expect `' + String.fromCharCode(code) + '`'); |
| } |
| |
| this.pos++; |
| }, |
| peek: function() { |
| return this.pos < this.str.length ? this.str.charAt(this.pos++) : ''; |
| }, |
| error: function(message) { |
| throw new SyntaxError(message, this.str, this.pos); |
| } |
| }; |
| |
| module.exports = Tokenizer; |