var utils = { /* Like Python's |range|, but without |step|. */ range: function(start, stop) { if (stop === undefined) { stop = start; start = 0; } var result = new Array(Math.max(0, stop - start)); for (var i = 0, j = start; j < stop; i++, j++) { result[i] = j; } return result; }, find: function(array, callback) { var length = array.length; for (var i = 0; i < length; i++) { if (callback(array[i])) { return array[i]; } } }, contains: function(array, value) { /* * Stupid IE does not have Array.prototype.indexOf, otherwise this function * would be a one-liner. */ var length = array.length; for (var i = 0; i < length; i++) { if (array[i] === value) { return true; } } return false; }, each: function(array, callback) { var length = array.length; for (var i = 0; i < length; i++) { callback(array[i], i); } }, map: function(array, callback) { var result = []; var length = array.length; for (var i = 0; i < length; i++) { result[i] = callback(array[i], i); } return result; }, pluck: function(array, key) { return utils.map(array, function (e) { return e[key]; }); }, keys: function(object) { var result = []; for (var key in object) { result.push(key); } return result; }, values: function(object) { var result = []; for (var key in object) { result.push(object[key]); } return result; }, clone: function(object) { var result = {}; for (var key in object) { result[key] = object[key]; } return result; }, defaults: function(object, defaults) { for (var key in defaults) { if (object[key] === undefined) { object[key] = defaults[key]; } } }, /* * The code needs to be in sync with the code template in the compilation * function for "action" nodes. */ subclass: function(child, parent) { function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); }, /* * Returns a string padded on the left to a desired length with a character. * * The code needs to be in sync with the code template in the compilation * function for "action" nodes. */ padLeft: function(input, padding, length) { var result = input; var padLength = length - input.length; for (var i = 0; i < padLength; i++) { result = padding + result; } return result; }, /* * Returns an escape sequence for given character. Uses \x for characters <= * 0xFF to save space, \u for the rest. * * The code needs to be in sync with the code template in the compilation * function for "action" nodes. */ escape: function(ch) { var charCode = ch.charCodeAt(0); var escapeChar; var length; if (charCode <= 0xFF) { escapeChar = 'x'; length = 2; } else { escapeChar = 'u'; length = 4; } return '\\' + escapeChar + utils.padLeft(charCode.toString(16).toUpperCase(), '0', length); }, /* * Surrounds the string with quotes and escapes characters inside so that the * result is a valid JavaScript string. * * The code needs to be in sync with the code template in the compilation * function for "action" nodes. */ quote: function(s) { /* * ECMA-262, 5th ed., 7.8.4: All characters may appear literally in a string * literal except for the closing quote character, backslash, carriage * return, line separator, paragraph separator, and line feed. Any character * may appear in the form of an escape sequence. * * For portability, we also escape escape all control and non-ASCII * characters. Note that "\0" and "\v" escape sequences are not used because * JSHint does not like the first and IE the second. */ return '"' + s .replace(/\\/g, '\\\\') // backslash .replace(/"/g, '\\"') // closing quote character .replace(/\x08/g, '\\b') // backspace .replace(/\t/g, '\\t') // horizontal tab .replace(/\n/g, '\\n') // line feed .replace(/\f/g, '\\f') // form feed .replace(/\r/g, '\\r') // carriage return .replace(/[\x00-\x07\x0B\x0E-\x1F\x80-\uFFFF]/g, utils.escape) + '"'; }, /* * Escapes characters inside the string so that it can be used as a list of * characters in a character class of a regular expression. */ quoteForRegexpClass: function(s) { /* * Based on ECMA-262, 5th ed., 7.8.5 & 15.10.1. * * For portability, we also escape escape all control and non-ASCII * characters. */ return s .replace(/\\/g, '\\\\') // backslash .replace(/\//g, '\\/') // closing slash .replace(/\]/g, '\\]') // closing bracket .replace(/\^/g, '\\^') // caret .replace(/-/g, '\\-') // dash .replace(/\0/g, '\\0') // null .replace(/\t/g, '\\t') // horizontal tab .replace(/\n/g, '\\n') // line feed .replace(/\v/g, '\\x0B') // vertical tab .replace(/\f/g, '\\f') // form feed .replace(/\r/g, '\\r') // carriage return .replace(/[\x01-\x08\x0E-\x1F\x80-\uFFFF]/g, utils.escape); }, /* * Builds a node visitor -- a function which takes a node and any number of * other parameters, calls an appropriate function according to the node type, * passes it all its parameters and returns its value. The functions for * various node types are passed in a parameter to |buildNodeVisitor| as a * hash. */ buildNodeVisitor: function(functions) { return function(node) { return functions[node.type].apply(null, arguments); }; }, findRuleByName: function(ast, name) { return utils.find(ast.rules, function(r) { return r.name === name; }); } }; module.exports = utils;