jsPerf.app is an online JavaScript performance benchmark test runner & jsperf.com mirror. It is a complete rewrite in homage to the once excellent jsperf.com now with hopefully a more modern & maintainable codebase.
jsperf.com URLs are mirrored at the same path, e.g:
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Can be accessed at:
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/*!
* XRegExp 3.0.0-pre
* <http://xregexp.com/>
* Steven Levithan © 2007-2012 MIT License
*/
/**
* XRegExp provides augmented, extensible regular expressions. You get new syntax, flags, and
* methods beyond what browsers support natively. XRegExp is also a regex utility belt with tools
* to make your client-side grepping simpler and more powerful, while freeing you from worrying
* about pesky cross-browser inconsistencies and the dubious `lastIndex` property.
*/
var XRegExp = (function(undefined) {
'use strict';
/* ==============================
* Private variables
* ============================== */
var // ...
// Property name used for extended regex instance data
REGEX_DATA = 'xregexp',
// Internal reference to the `XRegExp` object
self,
// Optional features that can be installed and uninstalled
features = {
astral: false,
natives: false
},
// Store native methods to use and restore ('native' is an ES3 reserved keyword)
nativ = {
exec: RegExp.prototype.exec,
test: RegExp.prototype.test,
match: String.prototype.match,
replace: String.prototype.replace,
split: String.prototype.split
},
// Storage for fixed/extended native methods
fixed = {},
// Storage for regexes cached by `XRegExp.cache`
cache = {},
// Storage for pattern details cached by the `XRegExp` constructor
patternCache = {},
// Storage for regex syntax tokens added internally or by `XRegExp.addToken`
tokens = [],
// Token scopes
defaultScope = 'default',
classScope = 'class',
// Regexes that match native regex syntax, including octals
nativeTokens = {
// Any native multicharacter token in default scope, or any single character
'default': /\\(?:0(?:[0-3][0-7]{0,2}|[4-7][0-7]?)?|[1-9]\d*|x[\dA-Fa-f]{2}|u[\dA-Fa-f]{4}|c[A-Za-z]|[\s\S])|\(\?[:=!]|[?*+]\?|{\d+(?:,\d*)?}\??|[\s\S]/,
// Any native multicharacter token in character class scope, or any single character
'class': /\\(?:[0-3][0-7]{0,2}|[4-7][0-7]?|x[\dA-Fa-f]{2}|u[\dA-Fa-f]{4}|c[A-Za-z]|[\s\S])|[\s\S]/
},
// Any backreference or dollar-prefixed character in replacement strings
replacementToken = /\$(?:{([\w$]+)}|(\d\d?|[\s\S]))/g,
// Check for correct `exec` handling of nonparticipating capturing groups
correctExecNpcg = nativ.exec.call(/()??/, '')[1] === undefined,
// Check for flag y support
hasNativeY = RegExp.prototype.sticky !== undefined,
// Tracker for known flags, including addon flags
registeredFlags = {
g: true,
i: true,
m: true,
y: hasNativeY
},
// Shortcut to `Object.prototype.toString`
toString = {}.toString,
// Shortcut to `XRegExp.addToken`
add;
/* ==============================
* Private functions
* ============================== */
/**
* Attaches named capture data and `XRegExp.prototype` properties to a regex object.
* @private
* @param {RegExp} regex Regex to augment.
* @param {Array} captureNames Array with capture names, or `null`.
* @param {Boolean} [addProto=false] Whether to attach `XRegExp.prototype` properties. Not
* attaching properties avoids a minor performance penalty.
* @returns {RegExp} Augmented regex.
*/
function augment(regex, captureNames, addProto) {
var p;
if (addProto) {
// Can't auto-inherit these since the XRegExp constructor returns a nonprimitive value
if (regex.__proto__) {
regex.__proto__ = self.prototype;
} else {
for (p in self.prototype) {
// A `self.prototype.hasOwnProperty(p)` check wouldn't be worth it here, since
// this is performance sensitive, and enumerable `Object.prototype` or
// `RegExp.prototype` extensions exist on `regex.prototype` anyway
regex[p] = self.prototype[p];
}
}
}
regex[REGEX_DATA] = {captureNames: captureNames};
return regex;
}
/**
* Removes any duplicate characters from the provided string.
* @private
* @param {String} str String to remove duplicate characters from.
* @returns {String} String with any duplicate characters removed.
*/
function clipDuplicates(str) {
return nativ.replace.call(str, /([\s\S])(?=[\s\S]*\1)/g, '');
}
/**
* Copies a regex object while preserving special properties for named capture and augmenting with
* `XRegExp.prototype` methods. The copy has a fresh `lastIndex` property (set to zero). Allows
* adding and removing native flags while copying the regex.
* @private
* @param {RegExp} regex Regex to copy.
* @param {Object} [options] Allows specifying native flags to add or remove while copying the
* regex, and whether to attach `XRegExp.prototype` properties.
* @returns {RegExp} Copy of the provided regex, possibly with modified flags.
*/
function copy(regex, options) {
if (!self.isRegExp(regex)) {
throw new TypeError('Type RegExp expected');
}
// Get native flags in use
var flags = nativ.exec.call(/\/([a-z]*)$/i, String(regex))[1];
options = options || {};
if (options.add) {
flags = clipDuplicates(flags + options.add);
}
if (options.remove) {
// Would need to escape `options.remove` if this was public
flags = nativ.replace.call(flags, new RegExp('[' + options.remove + ']+', 'g'), '');
}
// Augment with `XRegExp.prototype` methods, but use the native `RegExp` constructor and
// avoid searching for special tokens. That would be wrong for regexes constructed by
// `RegExp`, and unnecessary for regexes constructed by `XRegExp` because the regex has
// already undergone the translation to native regex syntax
regex = augment(
new RegExp(regex.source, flags),
hasNamedCapture(regex) ? regex[REGEX_DATA].captureNames.slice(0) : null,
options.addProto
);
return regex;
}
/**
* Returns a new copy of the object used to hold extended regex instance data, tailored for a
* native nonaugmented regex.
* @private
* @returns {Object} Object with base regex instance data.
*/
function getBaseProps() {
return {captureNames: null};
}
/**
* Determines whether a regex has extended instance data used to track capture names.
* @private
* @param {RegExp} regex Regex to check.
* @returns {Boolean} Whether the regex uses named capture.
*/
function hasNamedCapture(regex) {
return !!(regex[REGEX_DATA] && regex[REGEX_DATA].captureNames);
}
/**
* Returns the first index at which a given value can be found in an array.
* @private
* @param {Array} array Array to search.
* @param {*} value Value to locate in the array.
* @returns {Number} Zero-based index at which the item is found, or -1.
*/
function indexOf(array, value) {
// Use the native array method, if available
if (Array.prototype.indexOf) {
return array.indexOf(value);
}
var len = array.length, i;
// Not a very good shim, but good enough for XRegExp's use of it
for (i = 0; i < len; ++i) {
if (array[i] === value) {
return i;
}
}
return -1;
}
/**
* Determines whether a value is of the specified type, by resolving its internal [[Class]].
* @private
* @param {*} value Object to check.
* @param {String} type Type to check for, in TitleCase.
* @returns {Boolean} Whether the object matches the type.
*/
function isType(value, type) {
return toString.call(value) === '[object ' + type + ']';
}
/**
* Checks whether the next nonignorable token after the specified position is a quantifier.
* @private
* @param {String} pattern Pattern to search within.
* @param {Number} pos Index in `pattern` to search at.
* @param {String} flags Flags used by the pattern.
* @returns {Boolean} Whether the next token is a quantifier.
*/
function isQuantifierNext(pattern, pos, flags) {
return nativ.test.call(
flags.indexOf('x') > -1 ?
// Ignore any leading whitespace, line comments, and inline comments
/^(?:\s+|#.*|\(\?#[^)]*\))*(?:[?*+]|{\d+(?:,\d*)?})/ :
// Ignore any leading inline comments
/^(?:\(\?#[^)]*\))*(?:[?*+]|{\d+(?:,\d*)?})/,
pattern.slice(pos)
);
}
/**
* Checks for flag-related errors, and strips/applies flags in a leading mode modifier. Offloads
* the flag preparation logic from the `XRegExp` constructor.
* @private
* @param {String} pattern Regex pattern, possibly with a leading mode modifier.
* @param {String} flags Any combination of flags.
* @returns {Object} Object with properties `pattern` and `flags`.
*/
function prepareFlags(pattern, flags) {
var i;
// Recent browsers throw on duplicate flags, so copy this behavior for nonnative flags
if (clipDuplicates(flags) !== flags) {
throw new SyntaxError('Invalid duplicate regex flag ' + flags);
}
// Strip and apply a leading mode modifier with any combination of flags except g or y
pattern = nativ.replace.call(pattern, /^\(\?([\w$]+)\)/, function($0, $1) {
if (nativ.test.call(/[gy]/, $1)) {
throw new SyntaxError('Cannot use flag g or y in mode modifier ' + $0);
}
// Allow duplicate flags within the mode modifier
flags = clipDuplicates(flags + $1);
return '';
});
// Throw on unknown native or nonnative flags
for (i = 0; i < flags.length; ++i) {
if (!registeredFlags[flags.charAt(i)]) {
throw new SyntaxError('Unknown regex flag ' + flags.charAt(i));
}
}
return {
pattern: pattern,
flags: flags
};
}
/**
* Prepares an options object from the given value.
* @private
* @param {String|Object} value Value to convert to an options object.
* @returns {Object} Options object.
*/
function prepareOptions(value) {
value = value || {};
if (isType(value, 'String')) {
value = self.forEach(value, /[^\s,]+/, function(match) {
this[match] = true;
}, {});
}
return value;
}
/**
* Registers a flag so it doesn't throw an 'unknown flag' error.
* @private
* @param {String} flag Single-character flag to register.
*/
function registerFlag(flag) {
if (!/^[\w$]$/.test(flag)) {
throw new Error('Flag must be a single character A-Za-z0-9_$');
}
registeredFlags[flag] = true;
}
/**
* Runs built-in and custom regex syntax tokens in reverse insertion order at the specified
* position, until a match is found.
* @private
* @param {String} pattern Original pattern from which an XRegExp object is being built.
* @param {String} flags Flags being used to construct the regex.
* @param {Number} pos Position to search for tokens within `pattern`.
* @param {Number} scope Regex scope to apply: 'default' or 'class'.
* @param {Object} context Context object to use for token handler functions.
* @returns {Object} Object with properties `matchLength`, `output`, and `reparse`; or `null`.
*/
function runTokens(pattern, flags, pos, scope, context) {
var i = tokens.length,
result = null,
match,
t;
// Run in reverse insertion order
while (i--) {
t = tokens[i];
if (
(t.scope === scope || t.scope === 'all') &&
(!t.flag || flags.indexOf(t.flag) > -1)
) {
match = self.exec(pattern, t.regex, pos, 'sticky');
if (match) {
result = {
matchLength: match[0].length,
output: t.handler.call(context, match, scope, flags),
reparse: t.reparse
};
// Finished with token tests
break;
}
}
}
return result;
}
/**
* Enables or disables implicit astral mode opt-in.
* @private
* @param {Boolean} on `true` to enable; `false` to disable.
*/
function setAstral(on) {
// Reset the pattern cache used by the `XRegExp` constructor, since the same pattern and
// flags might now produce different results
self.cache.flush('patterns');
features.astral = on;
}
/**
* Enables or disables native method overrides.
* @private
* @param {Boolean} on `true` to enable; `false` to disable.
*/
function setNatives(on) {
RegExp.prototype.exec = (on ? fixed : nativ).exec;
RegExp.prototype.test = (on ? fixed : nativ).test;
String.prototype.match = (on ? fixed : nativ).match;
String.prototype.replace = (on ? fixed : nativ).replace;
String.prototype.split = (on ? fixed : nativ).split;
features.natives = on;
}
/**
* Returns the object, or throws an error if it is `null` or `undefined`. This is used to follow
* the ES5 abstract operation `ToObject`.
* @private
* @param {*} value Object to check and return.
* @returns {*} The provided object.
*/
function toObject(value) {
// This matches both `null` and `undefined`
if (value == null) {
throw new TypeError('Cannot convert null or undefined to object');
}
return value;
}
/* ==============================
* Constructor
* ============================== */
/**
* Creates an extended regular expression object for matching text with a pattern. Differs from a
* native regular expression in that additional syntax and flags are supported. The returned object
* is in fact a native `RegExp` and works with all native methods.
* @class XRegExp
* @constructor
* @param {String|RegExp} pattern Regex pattern string, or an existing regex object to copy.
* @param {String} [flags] Any combination of flags.
* Native flags:
* <li>`g` - global
* <li>`i` - ignore case
* <li>`m` - multiline anchors
* <li>`y` - sticky (Firefox 3+)
* Additional XRegExp flags:
* <li>`n` - explicit capture
* <li>`s` - dot matches all (aka singleline)
* <li>`x` - free-spacing and line comments (aka extended)
* <li>`A` - astral (requires the Unicode Base addon)
* Flags cannot be provided when constructing one `RegExp` from another.
* @returns {RegExp} Extended regular expression object.
* @example
*
* // With named capture and flag x
* XRegExp('(?<year> [0-9]{4} ) -? # year \n\
* (?<month> [0-9]{2} ) -? # month \n\
* (?<day> [0-9]{2} ) # day ', 'x');
*
* // Providing a regex object copies it. Native regexes are recompiled using native (not XRegExp)
* // syntax. Copies maintain special properties for named capture, are augmented with
* // `XRegExp.prototype` methods, and have fresh `lastIndex` properties (set to zero).
* XRegExp(/regex/);
*/
self = function(pattern, flags) {
var context = {
hasNamedCapture: false,
captureNames: []
},
scope = defaultScope,
output = '',
pos = 0,
result,
token,
key;
if (self.isRegExp(pattern)) {
if (flags !== undefined) {
throw new TypeError('Cannot supply flags when copying a RegExp');
}
return copy(pattern, {addProto: true});
}
// Copy the argument behavior of `RegExp`
pattern = pattern === undefined ? '' : String(pattern);
flags = flags === undefined ? '' : String(flags);
// Cache-lookup key; intentionally using an invalid regex sequence as the separator
key = pattern + '***' + flags;
if (!patternCache[key]) {
// Check for flag-related errors, and strip/apply flags in a leading mode modifier
result = prepareFlags(pattern, flags);
pattern = result.pattern;
flags = result.flags;
// Use XRegExp's syntax tokens to translate the pattern to a native regex pattern...
// `pattern.length` may change on each iteration, if tokens use the `reparse` option
while (pos < pattern.length) {
do {
// Check for custom tokens at the current position
result = runTokens(pattern, flags, pos, scope, context);
// If the matched token used the `reparse` option, splice its output into the
// pattern before running tokens again at the same position
if (result && result.reparse) {
pattern = pattern.slice(0, pos) +
result.output +
pattern.slice(pos + result.matchLength);
}
} while (result && result.reparse);
if (result) {
output += result.output;
pos += (result.matchLength || 1);
} else {
// Get the native token at the current position
token = self.exec(pattern, nativeTokens[scope], pos, 'sticky')[0];
output += token;
pos += token.length;
if (token === '[' && scope === defaultScope) {
scope = classScope;
} else if (token === ']' && scope === classScope) {
scope = defaultScope;
}
}
}
patternCache[key] = {
// Cleanup token cruft: repeated `(?:)(?:)` and leading/trailing `(?:)`
pattern: nativ.replace.call(output, /\(\?:\)(?=\(\?:\))|^\(\?:\)|\(\?:\)$/g, ''),
// Strip all but native flags
flags: nativ.replace.call(flags, /[^gimy]+/g, ''),
// `context.captureNames` has an item for each capturing group, even if unnamed
captures: context.hasNamedCapture ? context.captureNames : null
}
}
key = patternCache[key];
return augment(new RegExp(key.pattern, key.flags), key.captures, /*addProto*/ true);
};
// Add `RegExp.prototype` to the prototype chain
self.prototype = new RegExp;
/* ==============================
* Public properties
* ============================== */
/**
* The XRegExp version number.
* @static
* @memberOf XRegExp
* @type String
*/
self.version = '3.0.0-pre';
/* ==============================
* Public methods
* ============================== */
/**
* Extends XRegExp syntax and allows custom flags. This is used internally and can be used to
* create XRegExp addons. If more than one token can match the same string, the last added wins.
* @memberOf XRegExp
* @param {RegExp} regex Regex object that matches the new token.
* @param {Function} handler Function that returns a new pattern string (using native regex syntax)
* to replace the matched token within all future XRegExp regexes. Has access to persistent
* properties of the regex being built, through `this`. Invoked with three arguments:
* <li>The match array, with named backreference properties.
* <li>The regex scope where the match was found: 'default' or 'class'.
* <li>The flags used by the regex, including any flags in a leading mode modifier.
* The handler function becomes part of the XRegExp construction process, so be careful not to
* construct XRegExps within the function or you will trigger infinite recursion.
* @param {Object} [options] Options object with optional properties:
* <li>`scope` {String} Scope where the token applies: 'default', 'class', or 'all'.
* <li>`flag` {String} Single-character flag that triggers the token. This also registers the
* flag, which prevents XRegExp from throwing an 'unknown flag' error when the flag is used.
* <li>`optionalFlags` {String} Any custom flags checked for within the token `handler` that are
* not required to trigger the token. This registers the flags, to prevent XRegExp from
* throwing an 'unknown flag' error when any of the flags are used.
* <li>`reparse` {Boolean} Whether the `handler` function's output should not be treated as
* final, and instead be reparseable by other tokens (including the current token). Allows
* token chaining or deferring.
* @example
*
* // Basic usage: Add \a for the ALERT control code
* XRegExp.addToken(
* /\\a/,
* function() {return '\\x07';},
* {scope: 'all'}
* );
* XRegExp('\\a[\\a-\\n]+').test('\x07\n\x07'); // -> true
*
* // Add the U (ungreedy) flag from PCRE and RE2, which reverses greedy and lazy quantifiers
* XRegExp.addToken(
* /([?*+]|{\d+(?:,\d*)?})(\??)/,
* function(match) {return match[1] + (match[2] ? '' : '?');},
* {flag: 'U'}
* );
* XRegExp('a+', 'U').exec('aaa')[0]; // -> 'a'
* XRegExp('a+?', 'U').exec('aaa')[0]; // -> 'aaa'
*/
self.addToken = function(regex, handler, options) {
options = options || {};
var optionalFlags = options.optionalFlags, i;
if (options.flag) {
registerFlag(options.flag);
}
if (optionalFlags) {
optionalFlags = nativ.split.call(optionalFlags, '');
for (i = 0; i < optionalFlags.length; ++i) {
registerFlag(optionalFlags[i]);
}
}
// Add to the private list of syntax tokens
tokens.push({
regex: copy(regex, {add: 'g' + (hasNativeY ? 'y' : '')}),
handler: handler,
scope: options.scope || defaultScope,
flag: options.flag,
reparse: options.reparse
});
// Reset the pattern cache used by the `XRegExp` constructor, since the same pattern and
// flags might now produce different results
self.cache.flush('patterns');
};
/**
* Caches and returns the result of calling `XRegExp(pattern, flags)`. On any subsequent call with
* the same pattern and flag combination, the cached copy of the regex is returned.
* @memberOf XRegExp
* @param {String} pattern Regex pattern string.
* @param {String} [flags] Any combination of XRegExp flags.
* @returns {RegExp} Cached XRegExp object.
* @example
*
* while (match = XRegExp.cache('.', 'gs').exec(str)) {
* // The regex is compiled once only
* }
*/
self.cache = function(pattern, flags) {
var key = pattern + '***' + (flags || '');
return cache[key] || (cache[key] = self(pattern, flags));
};
// Intentionally undocumented
self.cache.flush = function(cacheName) {
if (cacheName === 'patterns') {
// Flush the pattern cache used by the `XRegExp` constructor
patternCache = {};
} else {
// Flush the regex object cache populated by `XRegExp.cache`
cache = {};
}
};
/**
* Escapes any regular expression metacharacters, for use when matching literal strings. The result
* can safely be used at any point within a regex that uses any flags.
* @memberOf XRegExp
* @param {String} str String to escape.
* @returns {String} String with regex metacharacters escaped.
* @example
*
* XRegExp.escape('Escaped? <.>');
* // -> 'Escaped\?\ <\.>'
*/
self.escape = function(str) {
return nativ.replace.call(toObject(str), /[-[\]{}()*+?.,\\^$|#\s]/g, '\\$&');
};
/**
* Executes a regex search in a specified string. Returns a match array or `null`. If the provided
* regex uses named capture, named backreference properties are included on the match array.
* Optional `pos` and `sticky` arguments specify the search start position, and whether the match
* must start at the specified position only. The `lastIndex` property of the provided regex is not
* used, but is updated for compatibility. Also fixes browser bugs compared to the native
* `RegExp.prototype.exec` and can be used reliably cross-browser.
* @memberOf XRegExp
* @param {String} str String to search.
* @param {RegExp} regex Regex to search with.
* @param {Number} [pos=0] Zero-based index at which to start the search.
* @param {Boolean|String} [sticky=false] Whether the match must start at the specified position
* only. The string `'sticky'` is accepted as an alternative to `true`.
* @returns {Array} Match array with named backreference properties, or `null`.
* @example
*
* // Basic use, with named backreference
* var match = XRegExp.exec('U+2620', XRegExp('U\\+(?<hex>[0-9A-F]{4})'));
* match.hex; // -> '2620'
*
* // With pos and sticky, in a loop
* var pos = 2, result = [], match;
* while (match = XRegExp.exec('<1><2><3><4>5<6>', /<(\d)>/, pos, 'sticky')) {
* result.push(match[1]);
* pos = match.index + match[0].length;
* }
* // result -> ['2', '3', '4']
*/
self.exec = function(str, regex, pos, sticky) {
var cacheFlags = 'g', match, r2;
if (hasNativeY && (sticky || (regex.sticky && sticky !== false))) {
cacheFlags += 'y';
}
regex[REGEX_DATA] = regex[REGEX_DATA] || getBaseProps();
// Shares cached copies with `XRegExp.match`/`replace`
r2 = regex[REGEX_DATA][cacheFlags] || (
regex[REGEX_DATA][cacheFlags] = copy(regex, {
add: cacheFlags,
remove: sticky === false ? 'y' : ''
})
);
r2.lastIndex = pos = pos || 0;
// Fixed `exec` required for `lastIndex` fix, named backreferences, etc.
match = fixed.exec.call(r2, str);
if (sticky && match && match.index !== pos) {
match = null;
}
if (regex.global) {
regex.lastIndex = match ? r2.lastIndex : 0;
}
return match;
};
/**
* Executes a provided function once per regex match.
* @memberOf XRegExp
* @param {String} str String to search.
* @param {RegExp} regex Regex to search with.
* @param {Function} callback Function to execute for each match. Invoked with four arguments:
* <li>The match array, with named backreference properties.
* <li>The zero-based match index.
* <li>The string being traversed.
* <li>The regex object being used to traverse the string.
* @param {*} [context] Object to use as `this` when executing `callback`.
* @returns {*} Provided `context` object.
* @example
*
* // Extracts every other digit from a string
* XRegExp.forEach('1a2345', /\d/, function(match, i) {
* if (i % 2) this.push(+match[0]);
* }, []);
* // -> [2, 4]
*/
self.forEach = function(str, regex, callback, context) {
var pos = 0,
i = -1,
match;
while ((match = self.exec(str, regex, pos))) {
// Because `regex` is provided to `callback`, the function can use the deprecated/
// nonstandard `RegExp.prototype.compile` to mutate the regex. However, since
// `XRegExp.exec` doesn't use `lastIndex` to set the search position, this can't lead
// to an infinite loop, at least. Actually, because of the way `XRegExp.exec` caches
// globalized versions of regexes, mutating the regex will not have any effect on the
// iteration or matched strings, which is a nice side effect that brings extra safety
callback.call(context, match, ++i, str, regex);
pos = match.index + (match[0].length || 1);
}
return context;
};
/**
* Copies a regex object and adds flag `g`. The copy maintains special properties for named
* capture, is augmented with `XRegExp.prototype` methods, and has a fresh `lastIndex` property
* (set to zero). Native regexes are not recompiled using XRegExp syntax.
* @memberOf XRegExp
* @param {RegExp} regex Regex to globalize.
* @returns {RegExp} Copy of the provided regex with flag `g` added.
* @example
*
* var globalCopy = XRegExp.globalize(/regex/);
* globalCopy.global; // -> true
*/
self.globalize = function(regex) {
return copy(regex, {add: 'g', addProto: true});
};
/**
* Installs optional features according to the specified options. Can be undone using
* {@link #XRegExp.uninstall}.
* @memberOf XRegExp
* @param {Object|String} options Options object or string.
* @example
*
* // With an options object
* XRegExp.install({
* // Enables support for astral code points in Unicode addons (implicitly sets flag A)
* astral: true,
*
* // Overrides native regex methods with fixed/extended versions that support named
* // backreferences and fix numerous cross-browser bugs
* natives: true
* });
*
* // With an options string
* XRegExp.install('astral natives');
*/
self.install = function(options) {
options = prepareOptions(options);
if (!features.astral && options.astral) {
setAstral(true);
}
if (!features.natives && options.natives) {
setNatives(true);
}
};
/**
* Checks whether an individual optional feature is installed.
* @memberOf XRegExp
* @param {String} feature Name of the feature to check. One of:
* <li>`natives`
* <li>`astral`
* @returns {Boolean} Whether the feature is installed.
* @example
*
* XRegExp.isInstalled('natives');
*/
self.isInstalled = function(feature) {
return !!(features[feature]);
};
/**
* Returns `true` if an object is a regex; `false` if it isn't. This works correctly for regexes
* created in another frame, when `instanceof` and `constructor` checks would fail.
* @memberOf XRegExp
* @param {*} value Object to check.
* @returns {Boolean} Whether the object is a `RegExp` object.
* @example
*
* XRegExp.isRegExp('string'); // -> false
* XRegExp.isRegExp(/regex/i); // -> true
* XRegExp.isRegExp(RegExp('^', 'm')); // -> true
* XRegExp.isRegExp(XRegExp('(?s).')); // -> true
*/
self.isRegExp = function(value) {
return toString.call(value) === '[object RegExp]';
//return isType(value, 'RegExp');
};
/**
* Returns the first matched string, or in global mode, an array containing all matched strings.
* This is essentially a more convenient re-implementation of `String.prototype.match` that gives
* the result types you actually want (string instead of `exec`-style array in match-first mode,
* and an empty array instead of `null` when no matches are found in match-all mode). It also lets
* you override flag g and ignore `lastIndex`, and fixes browser bugs.
* @memberOf XRegExp
* @param {String} str String to search.
* @param {RegExp} regex Regex to search with.
* @param {String} [scope='one'] Use 'one' to return the first match as a string. Use 'all' to
* return an array of all matched strings. If not explicitly specified and `regex` uses flag g,
* `scope` is 'all'.
* @returns {String|Array} In match-first mode: First match as a string, or `null`. In match-all
* mode: Array of all matched strings, or an empty array.
* @example
*
* // Match first
* XRegExp.match('abc', /\w/); // -> 'a'
* XRegExp.match('abc', /\w/g, 'one'); // -> 'a'
* XRegExp.match('abc', /x/g, 'one'); // -> null
*
* // Match all
* XRegExp.match('abc', /\w/g); // -> ['a', 'b', 'c']
* XRegExp.match('abc', /\w/, 'all'); // -> ['a', 'b', 'c']
* XRegExp.match('abc', /x/, 'all'); // -> []
*/
self.match = function(str, regex, scope) {
var global = (regex.global && scope !== 'one') || scope === 'all',
cacheFlags = (global ? 'g' : '') + (regex.sticky ? 'y' : ''),
result,
r2;
regex[REGEX_DATA] = regex[REGEX_DATA] || getBaseProps();
// Shares cached copies with `XRegExp.exec`/`replace`
r2 = regex[REGEX_DATA][cacheFlags || 'noGY'] || (
regex[REGEX_DATA][cacheFlags || 'noGY'] = copy(regex, {
add: cacheFlags,
remove: scope === 'one' ? 'g' : ''
})
);
result = nativ.match.call(toObject(str), r2);
if (regex.global) {
regex.lastIndex = (
(scope === 'one' && result) ?
// Can't use `r2.lastIndex` since `r2` is nonglobal in this case
(result.index + result[0].length) : 0
);
}
return global ? (result || []) : (result && result[0]);
};
/**
* Retrieves the matches from searching a string using a chain of regexes that successively search
* within previous matches. The provided `chain` array can contain regexes and objects with `regex`
* and `backref` properties. When a backreference is specified, the named or numbered backreference
* is passed forward to the next regex or returned.
* @memberOf XRegExp
* @param {String} str String to search.
* @param {Array} chain Regexes that each search for matches within preceding results.
* @returns {Array} Matches by the last regex in the chain, or an empty array.
* @example
*
* // Basic usage; matches numbers within <b> tags
* XRegExp.matchChain('1 <b>2</b> 3 <b>4 a 56</b>', [
* XRegExp('(?is)<b>.*?</b>'),
* /\d+/
* ]);
* // -> ['2', '4', '56']
*
* // Passing forward and returning specific backreferences
* html = '<a href="http://xregexp.com/api/">XRegExp</a>\
* <a href="http://www.google.com/">Google</a>';
* XRegExp.matchChain(html, [
* {regex: /<a href="([^"]+)">/i, backref: 1},
* {regex: XRegExp('(?i)^https?://(?<domain>[^/?#]+)'), backref: 'domain'}
* ]);
* // -> ['xregexp.com', 'www.google.com']
*/
self.matchChain = function(str, chain) {
return (function recurseChain(values, level) {
var item = chain[level].regex ? chain[level] : {regex: chain[level]},
matches = [],
addMatch = function(match) {
if (item.backref) {
/* Safari 4.0.5 (but not 5.0.5+) inappropriately uses sparse arrays to hold
* the `undefined`s for backreferences to nonparticipating capturing
* groups. In such cases, a `hasOwnProperty` or `in` check on its own would
* inappropriately throw the exception, so also check if the backreference
* is a number that is within the bounds of the array.
*/
if (!(match.hasOwnProperty(item.backref) || +item.backref < match.length)) {
throw new ReferenceError('Backreference to undefined group: ' + item.backref);
}
matches.push(match[item.backref] || '');
} else {
matches.push(match[0]);
}
},
i;
for (i = 0; i < values.length; ++i) {
self.forEach(values[i], item.regex, addMatch);
}
return ((level === chain.length - 1) || !matches.length) ?
matches :
recurseChain(matches, level + 1);
}([str], 0));
};
/**
* Returns a new string with one or all matches of a pattern replaced. The pattern can be a string
* or regex, and the replacement can be a string or a function to be called for each match. To
* perform a global search and replace, use the optional `scope` argument or include flag g if
* using a regex. Replacement strings can use `${n}` for named and numbered backreferences.
* Replacement functions can use named backreferences via `arguments[0].name`. Also fixes browser
* bugs compared to the native `String.prototype.replace` and can be used reliably cross-browser.
* @memberOf XRegExp
* @param {String} str String to search.
* @param {RegExp|String} search Search pattern to be replaced.
* @param {String|Function} replacement Replacement string or a function invoked to create it.
* Replacement strings can include special replacement syntax:
* <li>$$ - Inserts a literal $ character.
* <li>$&, $0 - Inserts the matched substring.
* <li>$` - Inserts the string that precedes the matched substring (left context).
* <li>$' - Inserts the string that follows the matched substring (right context).
* <li>$n, $nn - Where n/nn are digits referencing an existent capturing group, inserts
* backreference n/nn.
* <li>${n} - Where n is a name or any number of digits that reference an existent capturing
* group, inserts backreference n.
* Replacement functions are invoked with three or more arguments:
* <li>The matched substring (corresponds to $& above). Named backreferences are accessible as
* properties of this first argument.
* <li>0..n arguments, one for each backreference (corresponding to $1, $2, etc. above).
* <li>The zero-based index of the match within the total search string.
* <li>The total string being searched.
* @param {String} [scope='one'] Use 'one' to replace the first match only, or 'all'. If not
* explicitly specified and using a regex with flag g, `scope` is 'all'.
* @returns {String} New string with one or all matches replaced.
* @example
*
* // Regex search, using named backreferences in replacement string
* var name = XRegExp('(?<first>\\w+) (?<last>\\w+)');
* XRegExp.replace('John Smith', name, '${last}, ${first}');
* // -> 'Smith, John'
*
* // Regex search, using named backreferences in replacement function
* XRegExp.replace('John Smith', name, function(match) {
* return match.last + ', ' + match.first;
* });
* // -> 'Smith, John'
*
* // String search, with replace-all
* XRegExp.replace('RegExp builds RegExps', 'RegExp', 'XRegExp', 'all');
* // -> 'XRegExp builds XRegExps'
*/
self.replace = function(str, search, replacement, scope) {
var isRegex = self.isRegExp(search),
global = (search.global && scope !== 'one') || scope === 'all',
cacheFlags = (global ? 'g' : '') + (search.sticky ? 'y' : ''),
s2 = search,
result;
if (isRegex) {
search[REGEX_DATA] = search[REGEX_DATA] || getBaseProps();
// Shares cached copies with `XRegExp.exec`/`match`. Since a copy is used,
// `search`'s `lastIndex` isn't updated *during* replacement iterations
s2 = search[REGEX_DATA][cacheFlags || 'noGY'] || (
search[REGEX_DATA][cacheFlags || 'noGY'] = copy(search, {
add: cacheFlags,
remove: scope === 'one' ? 'g' : ''
})
);
} else if (global) {
s2 = new RegExp(self.escape(String(search)), 'g');
}
// Fixed `replace` required for named backreferences, etc.
result = fixed.replace.call(toObject(str), s2, replacement);
if (isRegex && search.global) {
// Fixes IE, Safari bug (last tested IE 9, Safari 5.1)
search.lastIndex = 0;
}
return result;
};
/**
* Performs batch processing of string replacements. Used like {@link #XRegExp.replace}, but
* accepts an array of replacement details. Later replacements operate on the output of earlier
* replacements. Replacement details are accepted as an array with a regex or string to search for,
* the replacement string or function, and an optional scope of 'one' or 'all'. Uses the XRegExp
* replacement text syntax, which supports named backreference properties via `${name}`.
* @memberOf XRegExp
* @param {String} str String to search.
* @param {Array} replacements Array of replacement detail arrays.
* @returns {String} New string with all replacements.
* @example
*
* str = XRegExp.replaceEach(str, [
* [XRegExp('(?<name>a)'), 'z${name}'],
* [/b/gi, 'y'],
* [/c/g, 'x', 'one'], // scope 'one' overrides /g
* [/d/, 'w', 'all'], // scope 'all' overrides lack of /g
* ['e', 'v', 'all'], // scope 'all' allows replace-all for strings
* [/f/g, function($0) {
* return $0.toUpperCase();
* }]
* ]);
*/
self.replaceEach = function(str, replacements) {
var i, r;
for (i = 0; i < replacements.length; ++i) {
r = replacements[i];
str = self.replace(str, r[0], r[1], r[2]);
}
return str;
};
/**
* Splits a string into an array of strings using a regex or string separator. Matches of the
* separator are not included in the result array. However, if `separator` is a regex that contains
* capturing groups, backreferences are spliced into the result each time `separator` is matched.
* Fixes browser bugs compared to the native `String.prototype.split` and can be used reliably
* cross-browser.
* @memberOf XRegExp
* @param {String} str String to split.
* @param {RegExp|String} separator Regex or string to use for separating the string.
* @param {Number} [limit] Maximum number of items to include in the result array.
* @returns {Array} Array of substrings.
* @example
*
* // Basic use
* XRegExp.split('a b c', ' ');
* // -> ['a', 'b', 'c']
*
* // With limit
* XRegExp.split('a b c', ' ', 2);
* // -> ['a', 'b']
*
* // Backreferences in result array
* XRegExp.split('..word1..', /([a-z]+)(\d+)/i);
* // -> ['..', 'word', '1', '..']
*/
self.split = function(str, separator, limit) {
return fixed.split.call(toObject(str), separator, limit);
};
/**
* Executes a regex search in a specified string. Returns `true` or `false`. Optional `pos` and
* `sticky` arguments specify the search start position, and whether the match must start at the
* specified position only. The `lastIndex` property of the provided regex is not used, but is
* updated for compatibility. Also fixes browser bugs compared to the native
* `RegExp.prototype.test` and can be used reliably cross-browser.
* @memberOf XRegExp
* @param {String} str String to search.
* @param {RegExp} regex Regex to search with.
* @param {Number} [pos=0] Zero-based index at which to start the search.
* @param {Boolean|String} [sticky=false] Whether the match must start at the specified position
* only. The string `'sticky'` is accepted as an alternative to `true`.
* @returns {Boolean} Whether the regex matched the provided value.
* @example
*
* // Basic use
* XRegExp.test('abc', /c/); // -> true
*
* // With pos and sticky
* XRegExp.test('abc', /c/, 0, 'sticky'); // -> false
*/
self.test = function(str, regex, pos, sticky) {
// Do this the easy way :-)
return !!self.exec(str, regex, pos, sticky);
};
/**
* Uninstalls optional features according to the specified options. All optional features start out
* uninstalled, so this is used to undo the actions of {@link #XRegExp.install}.
* @memberOf XRegExp
* @param {Object|String} options Options object or string.
* @example
*
* // With an options object
* XRegExp.uninstall({
* // Disables support for astral code points in Unicode addons
* astral: true,
*
* // Restores native regex methods
* natives: true
* });
*
* // With an options string
* XRegExp.uninstall('astral natives');
*/
self.uninstall = function(options) {
options = prepareOptions(options);
if (features.astral && options.astral) {
setAstral(false);
}
if (features.natives && options.natives) {
setNatives(false);
}
};
/**
* Returns an XRegExp object that is the union of the given patterns. Patterns can be provided as
* regex objects or strings. Metacharacters are escaped in patterns provided as strings.
* Backreferences in provided regex objects are automatically renumbered to work correctly within
* the larger combined pattern. Native flags used by provided regexes are ignored in favor of the
* `flags` argument.
* @memberOf XRegExp
* @param {Array} patterns Regexes and strings to combine.
* @param {String} [flags] Any combination of XRegExp flags.
* @returns {RegExp} Union of the provided regexes and strings.
* @example
*
* XRegExp.union(['a+b*c', /(dogs)\1/, /(cats)\1/], 'i');
* // -> /a\+b\*c|(dogs)\1|(cats)\2/i
*/
self.union = function(patterns, flags) {
var parts = /(\()(?!\?)|\\([1-9]\d*)|\\[\s\S]|\[(?:[^\\\]]|\\[\s\S])*]/g,
output = [],
numCaptures = 0,
numPriorCaptures,
captureNames,
pattern,
rewrite = function(match, paren, backref) {
var name = captureNames[numCaptures - numPriorCaptures];
// Capturing group
if (paren) {
++numCaptures;
// If the current capture has a name, preserve the name
if (name) {
return '(?<' + name + '>';
}
// Backreference
} else if (backref) {
// Rewrite the backreference
return '\\' + (+backref + numPriorCaptures);
}
return match;
},
i;
if (!(isType(patterns, 'Array') && patterns.length)) {
throw new TypeError('Must provide a nonempty array of patterns to merge');
}
for (i = 0; i < patterns.length; ++i) {
pattern = patterns[i];
if (self.isRegExp(pattern)) {
numPriorCaptures = numCaptures;
captureNames = (pattern[REGEX_DATA] && pattern[REGEX_DATA].captureNames) || [];
// Rewrite backreferences. Passing to XRegExp dies on octals and ensures patterns
// are independently valid; helps keep this simple. Named captures are put back
output.push(nativ.replace.call(self(pattern.source).source, parts, rewrite));
} else {
output.push(self.escape(pattern));
}
}
return self(output.join('|'), flags);
};
/* ==============================
* Fixed/extended native methods
* ============================== */
/**
* Adds named capture support (with backreferences returned as `result.name`), and fixes browser
* bugs in the native `RegExp.prototype.exec`. Calling `XRegExp.install('natives')` uses this to
* override the native method. Use via `XRegExp.exec` without overriding natives.
* @private
* @param {String} str String to search.
* @returns {Array} Match array with named backreference properties, or `null`.
*/
fixed.exec = function(str) {
var origLastIndex = this.lastIndex,
match = nativ.exec.apply(this, arguments),
name,
r2,
i;
if (match) {
// Fix browsers whose `exec` methods don't return `undefined` for nonparticipating
// capturing groups. This fixes IE 5.5-8, but not IE 9's quirks mode or emulation of
// older IEs. IE 9 in standards mode follows the spec
if (!correctExecNpcg && match.length > 1 && indexOf(match, '') > -1) {
r2 = copy(this, {remove: 'g'});
// Using `str.slice(match.index)` rather than `match[0]` in case lookahead allowed
// matching due to characters outside the match
nativ.replace.call(String(str).slice(match.index), r2, function() {
var len = arguments.length, i;
// Skip index 0 and the last 2
for (i = 1; i < len - 2; ++i) {
if (arguments[i] === undefined) {
match[i] = undefined;
}
}
});
}
// Attach named capture properties
if (this[REGEX_DATA] && this[REGEX_DATA].captureNames) {
// Skip index 0
for (i = 1; i < match.length; ++i) {
name = this[REGEX_DATA].captureNames[i - 1];
if (name) {
match[name] = match[i];
}
}
}
// Fix browsers that increment `lastIndex` after zero-length matches
if (this.global && !match[0].length && (this.lastIndex > match.index)) {
this.lastIndex = match.index;
}
}
if (!this.global) {
// Fixes IE, Opera bug (last tested IE 9, Opera 11.6)
this.lastIndex = origLastIndex;
}
return match;
};
/**
* Fixes browser bugs in the native `RegExp.prototype.test`. Calling `XRegExp.install('natives')`
* uses this to override the native method.
* @private
* @param {String} str String to search.
* @returns {Boolean} Whether the regex matched the provided value.
*/
fixed.test = function(str) {
// Do this the easy way :-)
return !!fixed.exec.call(this, str);
};
/**
* Adds named capture support (with backreferences returned as `result.name`), and fixes browser
* bugs in the native `String.prototype.match`. Calling `XRegExp.install('natives')` uses this to
* override the native method.
* @private
* @param {RegExp|*} regex Regex to search with. If not a regex object, it is passed to `RegExp`.
* @returns {Array} If `regex` uses flag g, an array of match strings or `null`. Without flag g,
* the result of calling `regex.exec(this)`.
*/
fixed.match = function(regex) {
var result;
if (!self.isRegExp(regex)) {
// Use the native `RegExp` rather than `XRegExp`
regex = new RegExp(regex);
} else if (regex.global) {
result = nativ.match.apply(this, arguments);
// Fixes IE bug
regex.lastIndex = 0;
return result;
}
return fixed.exec.call(regex, toObject(this));
};
/**
* Adds support for `${n}` tokens for named and numbered backreferences in replacement text, and
* provides named backreferences to replacement functions as `arguments[0].name`. Also fixes
* browser bugs in replacement text syntax when performing a replacement using a nonregex search
* value, and the value of a replacement regex's `lastIndex` property during replacement iterations
* and upon completion. Note that this doesn't support SpiderMonkey's proprietary third (`flags`)
* argument. Calling `XRegExp.install('natives')` uses this to override the native method. Use via
* `XRegExp.replace` without overriding natives.
* @private
* @param {RegExp|String} search Search pattern to be replaced.
* @param {String|Function} replacement Replacement string or a function invoked to create it.
* @returns {String} New string with one or all matches replaced.
*/
fixed.replace = function(search, replacement) {
var isRegex = self.isRegExp(search),
origLastIndex,
captureNames,
result;
if (isRegex) {
if (search[REGEX_DATA]) {
captureNames = search[REGEX_DATA].captureNames;
}
// Only needed if `search` is nonglobal
origLastIndex = search.lastIndex;
} else {
search += ''; // Type-convert
}
// Don't use `typeof`; some older browsers return 'function' for regex objects
if (isType(replacement, 'Function')) {
// Stringifying `this` fixes a bug in IE < 9 where the last argument in replacement
// functions isn't type-converted to a string
result = nativ.replace.call(String(this), search, function() {
var args = arguments, i;
if (captureNames) {
// Change the `arguments[0]` string primitive to a `String` object that can
// store properties. This really does need to use `String` as a constructor
args[0] = new String(args[0]);
// Store named backreferences on the first argument
for (i = 0; i < captureNames.length; ++i) {
if (captureNames[i]) {
args[0][captureNames[i]] = args[i + 1];
}
}
}
// Update `lastIndex` before calling `replacement`. Fixes IE, Chrome, Firefox,
// Safari bug (last tested IE 9, Chrome 17, Firefox 11, Safari 5.1)
if (isRegex && search.global) {
search.lastIndex = args[args.length - 2] + args[0].length;
}
// Should pass `undefined` as context; see
// <https://bugs.ecmascript.org/show_bug.cgi?id=154>
return replacement.apply(undefined, args);
});
} else {
// Ensure that the last value of `args` will be a string when given nonstring `this`,
// while still throwing on `null` or `undefined` context
result = nativ.replace.call(this == null ? this : String(this), search, function() {
// Keep this function's `arguments` available through closure
var args = arguments;
return nativ.replace.call(String(replacement), replacementToken, function($0, $1, $2) {
var n;
// Named or numbered backreference with curly braces
if ($1) {
/* XRegExp behavior for `${n}`:
* 1. Backreference to numbered capture, if `n` is an integer. Use `0` for
* for the entire match. Any number of leading zeros may be used.
* 2. Backreference to named capture `n`, if it exists and is not an
* integer overridden by numbered capture. In practice, this does not
* overlap with numbered capture since XRegExp does not allow named
* capture to use a bare integer as the name.
* 3. If the name or number does not refer to an existing capturing group,
* it's an error.
*/
n = +$1; // Type-convert; drop leading zeros
if (n <= args.length - 3) {
return args[n] || '';
}
// Groups with the same name is an error, else would need `lastIndexOf`
n = captureNames ? indexOf(captureNames, $1) : -1;
if (n < 0) {
throw new SyntaxError('Backreference to undefined group ' + $0);
}
return args[n + 1] || '';
}
// Else, special variable or numbered backreference without curly braces
if ($2 === '$') { // $$
return '$';
}
if ($2 === '&' || +$2 === 0) { // $&, $0 (not followed by 1-9), $00
return args[0];
}
if ($2 === '`') { // $` (left context)
return args[args.length - 1].slice(0, args[args.length - 2]);
}
if ($2 === "'") { // $' (right context)
return args[args.length - 1].slice(args[args.length - 2] + args[0].length);
}
// Else, numbered backreference without curly braces
$2 = +$2; // Type-convert; drop leading zero
/* XRegExp behavior for `$n` and `$nn`:
* - Backrefs end after 1 or 2 digits. Use `${..}` for more digits.
* - `$1` is an error if no capturing groups.
* - `$10` is an error if less than 10 capturing groups. Use `${1}0` instead.
* - `$01` is `$1` if at least one capturing group, else it's an error.
* - `$0` (not followed by 1-9) and `$00` are the entire match.
* Native behavior, for comparison:
* - Backrefs end after 1 or 2 digits. Cannot reference capturing group 100+.
* - `$1` is a literal `$1` if no capturing groups.
* - `$10` is `$1` followed by a literal `0` if less than 10 capturing groups.
* - `$01` is `$1` if at least one capturing group, else it's a literal `$01`.
* - `$0` is a literal `$0`.
*/
if (!isNaN($2)) {
if ($2 > args.length - 3) {
throw new SyntaxError('Backreference to undefined group ' + $0);
}
return args[$2] || '';
}
throw new SyntaxError('Invalid token ' + $0);
});
});
}
if (isRegex) {
if (search.global) {
// Fixes IE, Safari bug (last tested IE 9, Safari 5.1)
search.lastIndex = 0;
} else {
// Fixes IE, Opera bug (last tested IE 9, Opera 11.6)
search.lastIndex = origLastIndex;
}
}
return result;
};
/**
* Fixes browser bugs in the native `String.prototype.split`. Calling `XRegExp.install('natives')`
* uses this to override the native method. Use via `XRegExp.split` without overriding natives.
* @private
* @param {RegExp|String} separator Regex or string to use for separating the string.
* @param {Number} [limit] Maximum number of items to include in the result array.
* @returns {Array} Array of substrings.
*/
fixed.split = function(separator, limit) {
if (!self.isRegExp(separator)) {
// Browsers handle nonregex split correctly, so use the faster native method
return nativ.split.apply(this, arguments);
}
var str = String(this),
output = [],
origLastIndex = separator.lastIndex,
lastLastIndex = 0,
lastLength;
/* Values for `limit`, per the spec:
* If undefined: pow(2,32) - 1
* If 0, Infinity, or NaN: 0
* If positive number: limit = floor(limit); if (limit >= pow(2,32)) limit -= pow(2,32);
* If negative number: pow(2,32) - floor(abs(limit))
* If other: Type-convert, then use the above rules
*/
// This line fails in very strange ways for some values of `limit` in Opera 10.5-10.63,
// unless Opera Dragonfly is open (go figure). It works in at least Opera 9.5-10.1 and 11+
limit = (limit === undefined ? -1 : limit) >>> 0;
self.forEach(str, separator, function(match) {
// This condition is not the same as `if (match[0].length)`
if ((match.index + match[0].length) > lastLastIndex) {
output.push(str.slice(lastLastIndex, match.index));
if (match.length > 1 && match.index < str.length) {
Array.prototype.push.apply(output, match.slice(1));
}
lastLength = match[0].length;
lastLastIndex = match.index + lastLength;
}
});
if (lastLastIndex === str.length) {
if (!nativ.test.call(separator, '') || lastLength) {
output.push('');
}
} else {
output.push(str.slice(lastLastIndex));
}
separator.lastIndex = origLastIndex;
return output.length > limit ? output.slice(0, limit) : output;
};
/* ==============================
* Built-in syntax/flag tokens
* ============================== */
add = self.addToken;
/* Letter identity escapes that natively match literal characters: `\a`, `\A`, etc. These should be
* SyntaxErrors but are allowed in web reality. XRegExp makes them errors for cross-browser
* consistency and to reserve their syntax, but lets them be superseded by addons.
*/
add(
/\\([ABCE-RTUVXYZaeg-mopqyz]|c(?![A-Za-z])|u(?![\dA-Fa-f]{4})|x(?![\dA-Fa-f]{2}))/,
function(match, scope) {
// \B is allowed in default scope only
if (match[1] === 'B' && scope === defaultScope) {
return match[0];
}
throw new SyntaxError('Invalid escape ' + match[0]);
},
{scope: 'all'}
);
/* Empty character class: `[]` or `[^]`. This fixes a critical cross-browser syntax inconsistency.
* Unless this is standardized (per the ES spec), regex syntax can't be accurately parsed because
* character class endings can't be determined.
*/
add(
/\[(\^?)]/,
function(match) {
// For cross-browser compatibility with ES3, convert [] to \b\B and [^] to [\s\S].
// (?!) should work like \b\B, but is unreliable in some versions of Firefox
return match[1] ? '[\\s\\S]' : '\\b\\B';
}
);
/* Comment pattern: `(?# )`. Inline comments are an alternative to the line comments allowed in
* free-spacing mode (flag x).
*/
add(
/\(\?#[^)]*\)/,
function(match, scope, flags) {
// Keep tokens separated unless the following token is a quantifier
return isQuantifierNext(match.input, match.index + match[0].length, flags) ?
'' : '(?:)';
}
);
/* Whitespace and line comments, in free-spacing mode (aka extended mode, flag x) only.
*/
add(
/\s+|#.*/,
function(match, scope, flags) {
// Keep tokens separated unless the following token is a quantifier
return isQuantifierNext(match.input, match.index + match[0].length, flags) ?
'' : '(?:)';
},
{flag: 'x'}
);
/* Dot, in dotall mode (aka singleline mode, flag s) only.
*/
add(
/\./,
function() {
return '[\\s\\S]';
},
{flag: 's'}
);
/* Named backreference: `\k<name>`. Backreference names can use the characters A-Z, a-z, 0-9, _,
* and $ only. Also allows numbered backreferences as `\k<n>`.
*/
add(
/\\k<([\w$]+)>/,
function(match) {
// Groups with the same name is an error, else would need `lastIndexOf`
var index = isNaN(match[1]) ? (indexOf(this.captureNames, match[1]) + 1) : +match[1],
endIndex = match.index + match[0].length;
if (!index || index > this.captureNames.length) {
throw new SyntaxError('Backreference to undefined group ' + match[0]);
}
// Keep backreferences separate from subsequent literal numbers
return '\\' + index + (
endIndex === match.input.length || isNaN(match.input.charAt(endIndex)) ?
'' : '(?:)'
);
}
);
/* Numbered backreference or octal, plus any following digits: `\0`, `\11`, etc. Octals except `\0`
* not followed by 0-9 and backreferences to unopened capture groups throw an error. Other matches
* are returned unaltered. IE < 9 doesn't support backreferences above `\99` in regex syntax.
*/
add(
/\\(\d+)/,
function(match, scope) {
if (
!(
scope === defaultScope &&
/^[1-9]/.test(match[1]) &&
+match[1] <= this.captureNames.length
) &&
match[1] !== '0'
) {
throw new SyntaxError('Cannot use octal escape or backreference to undefined group ' +
match[0]);
}
return match[0];
},
{scope: 'all'}
);
/* Named capturing group; match the opening delimiter only: `(?<name>`. Capture names can use the
* characters A-Z, a-z, 0-9, _, and $ only. Names can't be integers. Supports Python-style
* `(?P<name>` as an alternate syntax to avoid issues in recent Opera (which natively supports the
* Python-style syntax). Otherwise, XRegExp might treat numbered backreferences to Python-style
* named capture as octals.
*/
add(
/\(\?P?<([\w$]+)>/,
function(match) {
// Disallow bare integers as names because named backreferences are added to match
// arrays and therefore numeric properties may lead to incorrect lookups
if (!isNaN(match[1])) {
throw new SyntaxError('Cannot use integer as capture name ' + match[0]);
}
if (match[1] === 'length' || match[1] === '__proto__') {
throw new SyntaxError('Cannot use reserved word as capture name ' + match[0]);
}
if (indexOf(this.captureNames, match[1]) > -1) {
throw new SyntaxError('Cannot use same name for multiple groups ' + match[0]);
}
this.captureNames.push(match[1]);
this.hasNamedCapture = true;
return '(';
}
);
/* Capturing group; match the opening parenthesis only. Required for support of named capturing
* groups. Also adds explicit capture mode (flag n).
*/
add(
/\((?!\?)/,
function(match, scope, flags) {
if (flags.indexOf('n') > -1) {
return '(?:';
}
this.captureNames.push(null);
return '(';
},
{optionalFlags: 'n'}
);
/* ==============================
* Expose XRegExp
* ============================== */
return self;
}());
</script>var str = "this is a test string";Ready to run.
| Test | Ops/sec | |
|---|---|---|
| regex | | ready |
| xregexp | | ready |
You can edit these tests or add more tests to this page by appending /edit to the URL.