JavaScript + Unicode regexes

232
votes

How can I use Unicode-aware regular expressions in JavaScript?

For example, there should be something akin to \w that can match any code-point in Letters or Marks category (not just the ASCII ones), and hopefully have filters like [[P*]] for punctuation, etc.

11
javascriptregexunicodecharacter-properties
This doesn't include regular expression support but is useful for Unicode related tasks github.com/joelarson4/CharFunk – jwl

11 Answers

211
votes

Situation for ES 6

The ECMAScript language specification, edition 6 (also commonly known as ES2015), includes Unicode-aware regular expressions. Support must be enabled with the u modifier on the regex. See Unicode-aware regular expressions in ES6 for a break-down of the feature and some caveats.

ES6 is widely adopted in both browsers and stand-alone Javascript runtimes such as Node.js, so using this feature won't require extra effort in most cases. Full compatibility list: https://kangax.github.io/compat-table/es6/

Situation for ES 5 and below (legacy browsers)

There is a transpiler named regexpu that translates ES6 Unicode regular expressions into equivalent ES5. It can be used as part of your build process. Try it out online..

Even though JavaScript operates on Unicode strings, it does not implement Unicode-aware character classes and has no concept of POSIX character classes or Unicode blocks/sub-ranges.

63
votes

Personally, I would rather not install another library just to get this functionality. My answer does not require any external libraries, and it may also work with little modification for regex flavors besides JavaScript.

Unicode's website provides a way to translate Unicode categories into a set of code points. Since it's Unicode's website, the information from it should be accurate.

Note that you will need to exclude the high-end characters, as JavaScript can only handle characters less than FFFF (hex). I suggest checking the Abbreviate Collate, and Escape check boxes, which strike a balance between avoiding unprintable characters and minimizing the size of the regex.

Here are some common expansions of different Unicode properties:

\p{L} (Letters):

[A-Za-z\u00AA\u00B5\u00BA\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u02C1\u02C6-\u02D1\u02E0-\u02E4\u02EC\u02EE\u0370-\u0374\u0376\u0377\u037A-\u037D\u037F\u0386\u0388-\u038A\u038C\u038E-\u03A1\u03A3-\u03F5\u03F7-\u0481\u048A-\u052F\u0531-\u0556\u0559\u0561-\u0587\u05D0-\u05EA\u05F0-\u05F2\u0620-\u064A\u066E\u066F\u0671-\u06D3\u06D5\u06E5\u06E6\u06EE\u06EF\u06FA-\u06FC\u06FF\u0710\u0712-\u072F\u074D-\u07A5\u07B1\u07CA-\u07EA\u07F4\u07F5\u07FA\u0800-\u0815\u081A\u0824\u0828\u0840-\u0858\u08A0-\u08B4\u0904-\u0939\u093D\u0950\u0958-\u0961\u0971-\u0980\u0985-\u098C\u098F\u0990\u0993-\u09A8\u09AA-\u09B0\u09B2\u09B6-\u09B9\u09BD\u09CE\u09DC\u09DD\u09DF-\u09E1\u09F0\u09F1\u0A05-\u0A0A\u0A0F\u0A10\u0A13-\u0A28\u0A2A-\u0A30\u0A32\u0A33\u0A35\u0A36\u0A38\u0A39\u0A59-\u0A5C\u0A5E\u0A72-\u0A74\u0A85-\u0A8D\u0A8F-\u0A91\u0A93-\u0AA8\u0AAA-\u0AB0\u0AB2\u0AB3\u0AB5-\u0AB9\u0ABD\u0AD0\u0AE0\u0AE1\u0AF9\u0B05-\u0B0C\u0B0F\u0B10\u0B13-\u0B28\u0B2A-\u0B30\u0B32\u0B33\u0B35-\u0B39\u0B3D\u0B5C\u0B5D\u0B5F-\u0B61\u0B71\u0B83\u0B85-\u0B8A\u0B8E-\u0B90\u0B92-\u0B95\u0B99\u0B9A\u0B9C\u0B9E\u0B9F\u0BA3\u0BA4\u0BA8-\u0BAA\u0BAE-\u0BB9\u0BD0\u0C05-\u0C0C\u0C0E-\u0C10\u0C12-\u0C28\u0C2A-\u0C39\u0C3D\u0C58-\u0C5A\u0C60\u0C61\u0C85-\u0C8C\u0C8E-\u0C90\u0C92-\u0CA8\u0CAA-\u0CB3\u0CB5-\u0CB9\u0CBD\u0CDE\u0CE0\u0CE1\u0CF1\u0CF2\u0D05-\u0D0C\u0D0E-\u0D10\u0D12-\u0D3A\u0D3D\u0D4E\u0D5F-\u0D61\u0D7A-\u0D7F\u0D85-\u0D96\u0D9A-\u0DB1\u0DB3-\u0DBB\u0DBD\u0DC0-\u0DC6\u0E01-\u0E30\u0E32\u0E33\u0E40-\u0E46\u0E81\u0E82\u0E84\u0E87\u0E88\u0E8A\u0E8D\u0E94-\u0E97\u0E99-\u0E9F\u0EA1-\u0EA3\u0EA5\u0EA7\u0EAA\u0EAB\u0EAD-\u0EB0\u0EB2\u0EB3\u0EBD\u0EC0-\u0EC4\u0EC6\u0EDC-\u0EDF\u0F00\u0F40-\u0F47\u0F49-\u0F6C\u0F88-\u0F8C\u1000-\u102A\u103F\u1050-\u1055\u105A-\u105D\u1061\u1065\u1066\u106E-\u1070\u1075-\u1081\u108E\u10A0-\u10C5\u10C7\u10CD\u10D0-\u10FA\u10FC-\u1248\u124A-\u124D\u1250-\u1256\u1258\u125A-\u125D\u1260-\u1288\u128A-\u128D\u1290-\u12B0\u12B2-\u12B5\u12B8-\u12BE\u12C0\u12C2-\u12C5\u12C8-\u12D6\u12D8-\u1310\u1312-\u1315\u1318-\u135A\u1380-\u138F\u13A0-\u13F5\u13F8-\u13FD\u1401-\u166C\u166F-\u167F\u1681-\u169A\u16A0-\u16EA\u16F1-\u16F8\u1700-\u170C\u170E-\u1711\u1720-\u1731\u1740-\u1751\u1760-\u176C\u176E-\u1770\u1780-\u17B3\u17D7\u17DC\u1820-\u1877\u1880-\u18A8\u18AA\u18B0-\u18F5\u1900-\u191E\u1950-\u196D\u1970-\u1974\u1980-\u19AB\u19B0-\u19C9\u1A00-\u1A16\u1A20-\u1A54\u1AA7\u1B05-\u1B33\u1B45-\u1B4B\u1B83-\u1BA0\u1BAE\u1BAF\u1BBA-\u1BE5\u1C00-\u1C23\u1C4D-\u1C4F\u1C5A-\u1C7D\u1CE9-\u1CEC\u1CEE-\u1CF1\u1CF5\u1CF6\u1D00-\u1DBF\u1E00-\u1F15\u1F18-\u1F1D\u1F20-\u1F45\u1F48-\u1F4D\u1F50-\u1F57\u1F59\u1F5B\u1F5D\u1F5F-\u1F7D\u1F80-\u1FB4\u1FB6-\u1FBC\u1FBE\u1FC2-\u1FC4\u1FC6-\u1FCC\u1FD0-\u1FD3\u1FD6-\u1FDB\u1FE0-\u1FEC\u1FF2-\u1FF4\u1FF6-\u1FFC\u2071\u207F\u2090-\u209C\u2102\u2107\u210A-\u2113\u2115\u2119-\u211D\u2124\u2126\u2128\u212A-\u212D\u212F-\u2139\u213C-\u213F\u2145-\u2149\u214E\u2183\u2184\u2C00-\u2C2E\u2C30-\u2C5E\u2C60-\u2CE4\u2CEB-\u2CEE\u2CF2\u2CF3\u2D00-\u2D25\u2D27\u2D2D\u2D30-\u2D67\u2D6F\u2D80-\u2D96\u2DA0-\u2DA6\u2DA8-\u2DAE\u2DB0-\u2DB6\u2DB8-\u2DBE\u2DC0-\u2DC6\u2DC8-\u2DCE\u2DD0-\u2DD6\u2DD8-\u2DDE\u2E2F\u3005\u3006\u3031-\u3035\u303B\u303C\u3041-\u3096\u309D-\u309F\u30A1-\u30FA\u30FC-\u30FF\u3105-\u312D\u3131-\u318E\u31A0-\u31BA\u31F0-\u31FF\u3400-\u4DB5\u4E00-\u9FD5\uA000-\uA48C\uA4D0-\uA4FD\uA500-\uA60C\uA610-\uA61F\uA62A\uA62B\uA640-\uA66E\uA67F-\uA69D\uA6A0-\uA6E5\uA717-\uA71F\uA722-\uA788\uA78B-\uA7AD\uA7B0-\uA7B7\uA7F7-\uA801\uA803-\uA805\uA807-\uA80A\uA80C-\uA822\uA840-\uA873\uA882-\uA8B3\uA8F2-\uA8F7\uA8FB\uA8FD\uA90A-\uA925\uA930-\uA946\uA960-\uA97C\uA984-\uA9B2\uA9CF\uA9E0-\uA9E4\uA9E6-\uA9EF\uA9FA-\uA9FE\uAA00-\uAA28\uAA40-\uAA42\uAA44-\uAA4B\uAA60-\uAA76\uAA7A\uAA7E-\uAAAF\uAAB1\uAAB5\uAAB6\uAAB9-\uAABD\uAAC0\uAAC2\uAADB-\uAADD\uAAE0-\uAAEA\uAAF2-\uAAF4\uAB01-\uAB06\uAB09-\uAB0E\uAB11-\uAB16\uAB20-\uAB26\uAB28-\uAB2E\uAB30-\uAB5A\uAB5C-\uAB65\uAB70-\uABE2\uAC00-\uD7A3\uD7B0-\uD7C6\uD7CB-\uD7FB\uF900-\uFA6D\uFA70-\uFAD9\uFB00-\uFB06\uFB13-\uFB17\uFB1D\uFB1F-\uFB28\uFB2A-\uFB36\uFB38-\uFB3C\uFB3E\uFB40\uFB41\uFB43\uFB44\uFB46-\uFBB1\uFBD3-\uFD3D\uFD50-\uFD8F\uFD92-\uFDC7\uFDF0-\uFDFB\uFE70-\uFE74\uFE76-\uFEFC\uFF21-\uFF3A\uFF41-\uFF5A\uFF66-\uFFBE\uFFC2-\uFFC7\uFFCA-\uFFCF\uFFD2-\uFFD7\uFFDA-\uFFDC]

\p{Nd} (Number decimal digits):

[0-9\u0660-\u0669\u06F0-\u06F9\u07C0-\u07C9\u0966-\u096F\u09E6-\u09EF\u0A66-\u0A6F\u0AE6-\u0AEF\u0B66-\u0B6F\u0BE6-\u0BEF\u0C66-\u0C6F\u0CE6-\u0CEF\u0D66-\u0D6F\u0DE6-\u0DEF\u0E50-\u0E59\u0ED0-\u0ED9\u0F20-\u0F29\u1040-\u1049\u1090-\u1099\u17E0-\u17E9\u1810-\u1819\u1946-\u194F\u19D0-\u19D9\u1A80-\u1A89\u1A90-\u1A99\u1B50-\u1B59\u1BB0-\u1BB9\u1C40-\u1C49\u1C50-\u1C59\uA620-\uA629\uA8D0-\uA8D9\uA900-\uA909\uA9D0-\uA9D9\uA9F0-\uA9F9\uAA50-\uAA59\uABF0-\uABF9\uFF10-\uFF19]

\p{P} (Punctuation):

[!-#%-*,-/\:;?@\[-\]_\{\}\u00A1\u00A7\u00AB\u00B6\u00B7\u00BB\u00BF\u037E\u0387\u055A-\u055F\u0589\u058A\u05BE\u05C0\u05C3\u05C6\u05F3\u05F4\u0609\u060A\u060C\u060D\u061B\u061E\u061F\u066A-\u066D\u06D4\u0700-\u070D\u07F7-\u07F9\u0830-\u083E\u085E\u0964\u0965\u0970\u0AF0\u0DF4\u0E4F\u0E5A\u0E5B\u0F04-\u0F12\u0F14\u0F3A-\u0F3D\u0F85\u0FD0-\u0FD4\u0FD9\u0FDA\u104A-\u104F\u10FB\u1360-\u1368\u1400\u166D\u166E\u169B\u169C\u16EB-\u16ED\u1735\u1736\u17D4-\u17D6\u17D8-\u17DA\u1800-\u180A\u1944\u1945\u1A1E\u1A1F\u1AA0-\u1AA6\u1AA8-\u1AAD\u1B5A-\u1B60\u1BFC-\u1BFF\u1C3B-\u1C3F\u1C7E\u1C7F\u1CC0-\u1CC7\u1CD3\u2010-\u2027\u2030-\u2043\u2045-\u2051\u2053-\u205E\u207D\u207E\u208D\u208E\u2308-\u230B\u2329\u232A\u2768-\u2775\u27C5\u27C6\u27E6-\u27EF\u2983-\u2998\u29D8-\u29DB\u29FC\u29FD\u2CF9-\u2CFC\u2CFE\u2CFF\u2D70\u2E00-\u2E2E\u2E30-\u2E42\u3001-\u3003\u3008-\u3011\u3014-\u301F\u3030\u303D\u30A0\u30FB\uA4FE\uA4FF\uA60D-\uA60F\uA673\uA67E\uA6F2-\uA6F7\uA874-\uA877\uA8CE\uA8CF\uA8F8-\uA8FA\uA8FC\uA92E\uA92F\uA95F\uA9C1-\uA9CD\uA9DE\uA9DF\uAA5C-\uAA5F\uAADE\uAADF\uAAF0\uAAF1\uABEB\uFD3E\uFD3F\uFE10-\uFE19\uFE30-\uFE52\uFE54-\uFE61\uFE63\uFE68\uFE6A\uFE6B\uFF01-\uFF03\uFF05-\uFF0A\uFF0C-\uFF0F\uFF1A\uFF1B\uFF1F\uFF20\uFF3B-\uFF3D\uFF3F\uFF5B\uFF5D\uFF5F-\uFF65]

The page also recognizes a number of obscure character classes, such as \p{Hira}, which is just the (Japanese) Hiragana characters:

[\u3041-\u3096\u309D-\u309F]

Lastly, it's possible to plug a char class with more than one Unicode property to get a shorter regex than you would get by just combining them (as long as certain settings are checked).

53
votes

Having also not found a good solution, I wrote a small script a long time ago, by downloading data from the unicode specification (v.5.0.0) and generating intervals for each unicode category and subcategory in the BMP (lately replaced by a small Java program that uses its own native Unicode support).

Basically it converts \p{...} to a range of values, much like the output of the tool mentioned by Tomalak, but the intervals can end up quite large (since it's not dealing with blocks, but with characters scattered through many different places).

For instance, a Regex written like this:

var regex = unicode_hack(/\p{L}(\p{L}|\p{Nd})*/g);

Will be converted to something like this:

/[\u0041-\u005a\u0061-\u007a...]([...]|[\u0030-\u0039\u0660-\u0669...])*/g

Haven't used it a lot in practice, but it seems to work fine from my tests, so I'm posting here in case someone find it useful. Despite the length of the resulting regexes (the example above has 3591 characters when expanded), the performance seems to be acceptable (see the tests at jsFiddle; thanks to @modiX and @Lwangaman for the improvements).

Here's the source (raw, 27.5KB; minified, 24.9KB, not much better...). It might be made smaller by unescaping the unicode characters, but OTOH will run the risk of encoding issues, so I'm leaving as it is. Hopefully with ES6 this kind of thing won't be necessary anymore.

Update: this looks like the same strategy adopted in the XRegExp Unicode plug-in mentioned by Tim Down, except that in this case regular JavaScript regexes are being used.

31
votes

As mentioned in other answers, JavaScript regexes have no support for Unicode character classes. However, there is a library that does provide this: Steven Levithan's excellent XRegExp and its Unicode plug-in.

29
votes

[^\u0000-\u007F]+ for any characters which is not included ASCII characters.

For example:

function isNonLatinCharacters(s) {
    return /[^\u0000-\u007F]/.test(s);
}

console.log(isNonLatinCharacters("身分"));// Japanese
console.log(isNonLatinCharacters("测试"));// Chinese
console.log(isNonLatinCharacters("حمید"));// Persian
console.log(isNonLatinCharacters("테스트"));// Korean
console.log(isNonLatinCharacters("परीक्षण"));// Hindi
console.log(isNonLatinCharacters("מִבְחָן"));// Hebrew

Here are some perfect references:

Unicode range RegExp generator

Unicode Regular Expressions

Unicode 10.0 Character Code Charts

Match Unicode Block Range

26
votes

September 2018 (updated February 2019)

It seems that regexp /\p{L}/u for match letters (as unicode categories)

  • works on Chrome 68.0.3440.106 and Safari 11.1.2 (13605.3.8)
  • NOT working on Firefox 65.0 :(

Here is a working example

In below field you should be able to to type letters but not numbers<br>
<input type="text" name="field" onkeydown="return /\p{L}/u.test(event.key)" >

I report this bug here.

Update

After over 2 years according to: 1500035 > 1361876 > 1634135 finally this bug is fixed and will be available in Firefox v.78+

9
votes

This will do it:

/[A-Za-z\u00C0-\u00FF ]+/.exec('hipopótamo maçã pólen ñ poção água língüa')

It explicitly selects a range of unicode characters. It will work for latin characters, but other strange characters may be out of this range.

8
votes

In JavaScript, \w and \d are ASCII, while \s is Unicode. Don't ask me why. JavaScript does support \p with Unicode categories, which you can use to emulate a Unicode-aware \w and \d.

For \d use \p{N} (numbers)

For \w use [\p{L}\p{N}\p{Pc}\p{M}] (letters, numbers, underscores, marks)

Update: Unfortunately, I was wrong about this. JavaScript does does not officially support \p either, though some implementations may still support this. The only Unicode support in JavaScript regexes is matching specific code points with \uFFFF. You can use those in ranges in character classes.

6
votes

If you are using Babel then Unicode support is already available.

I also released a plugin which transforms your source code such that you can write regular expressions like /^\p{L}+$/. These will then be transformed into something that browsers understand.

Here is the project page of the plugin:

babel-plugin-utf-8-regex

4
votes

I'm answering this question
What would be the equivalent for \p{Lu} or \p{Ll} in regExp for js?
since it was marked as an exact duplicate of the current old question.

Querying the UCD Database of Unicode 12, \p{Lu} generates 1,788 code points.

Converting to UTF-16 yields the class construct equivalency.
It's only a 4k character string and is easily doable in any regex engines. 

(?:[\u0041-\u005A\u00C0-\u00D6\u00D8-\u00DE\u0100\u0102\u0104\u0106\u0108\u010A\u010C\u010E\u0110\u0112\u0114\u0116\u0118\u011A\u011C\u011E\u0120\u0122\u0124\u0126\u0128\u012A\u012C\u012E\u0130\u0132\u0134\u0136\u0139\u013B\u013D\u013F\u0141\u0143\u0145\u0147\u014A\u014C\u014E\u0150\u0152\u0154\u0156\u0158\u015A\u015C\u015E\u0160\u0162\u0164\u0166\u0168\u016A\u016C\u016E\u0170\u0172\u0174\u0176\u0178-\u0179\u017B\u017D\u0181-\u0182\u0184\u0186-\u0187\u0189-\u018B\u018E-\u0191\u0193-\u0194\u0196-\u0198\u019C-\u019D\u019F-\u01A0\u01A2\u01A4\u01A6-\u01A7\u01A9\u01AC\u01AE-\u01AF\u01B1-\u01B3\u01B5\u01B7-\u01B8\u01BC\u01C4\u01C7\u01CA\u01CD\u01CF\u01D1\u01D3\u01D5\u01D7\u01D9\u01DB\u01DE\u01E0\u01E2\u01E4\u01E6\u01E8\u01EA\u01EC\u01EE\u01F1\u01F4\u01F6-\u01F8\u01FA\u01FC\u01FE\u0200\u0202\u0204\u0206\u0208\u020A\u020C\u020E\u0210\u0212\u0214\u0216\u0218\u021A\u021C\u021E\u0220\u0222\u0224\u0226\u0228\u022A\u022C\u022E\u0230\u0232\u023A-\u023B\u023D-\u023E\u0241\u0243-\u0246\u0248\u024A\u024C\u024E\u0370\u0372\u0376\u037F\u0386\u0388-\u038A\u038C\u038E-\u038F\u0391-\u03A1\u03A3-\u03AB\u03CF\u03D2-\u03D4\u03D8\u03DA\u03DC\u03DE\u03E0\u03E2\u03E4\u03E6\u03E8\u03EA\u03EC\u03EE\u03F4\u03F7\u03F9-\u03FA\u03FD-\u042F\u0460\u0462\u0464\u0466\u0468\u046A\u046C\u046E\u0470\u0472\u0474\u0476\u0478\u047A\u047C\u047E\u0480\u048A\u048C\u048E\u0490\u0492\u0494\u0496\u0498\u049A\u049C\u049E\u04A0\u04A2\u04A4\u04A6\u04A8\u04AA\u04AC\u04AE\u04B0\u04B2\u04B4\u04B6\u04B8\u04BA\u04BC\u04BE\u04C0-\u04C1\u04C3\u04C5\u04C7\u04C9\u04CB\u04CD\u04D0\u04D2\u04D4\u04D6\u04D8\u04DA\u04DC\u04DE\u04E0\u04E2\u04E4\u04E6\u04E8\u04EA\u04EC\u04EE\u04F0\u04F2\u04F4\u04F6\u04F8\u04FA\u04FC\u04FE\u0500\u0502\u0504\u0506\u0508\u050A\u050C\u050E\u0510\u0512\u0514\u0516\u0518\u051A\u051C\u051E\u0520\u0522\u0524\u0526\u0528\u052A\u052C\u052E\u0531-\u0556\u10A0-\u10C5\u10C7\u10CD\u13A0-\u13F5\u1C90-\u1CBA\u1CBD-\u1CBF\u1E00\u1E02\u1E04\u1E06\u1E08\u1E0A\u1E0C\u1E0E\u1E10\u1E12\u1E14\u1E16\u1E18\u1E1A\u1E1C\u1E1E\u1E20\u1E22\u1E24\u1E26\u1E28\u1E2A\u1E2C\u1E2E\u1E30\u1E32\u1E34\u1E36\u1E38\u1E3A\u1E3C\u1E3E\u1E40\u1E42\u1E44\u1E46\u1E48\u1E4A\u1E4C\u1E4E\u1E50\u1E52\u1E54\u1E56\u1E58\u1E5A\u1E5C\u1E5E\u1E60\u1E62\u1E64\u1E66\u1E68\u1E6A\u1E6C\u1E6E\u1E70\u1E72\u1E74\u1E76\u1E78\u1E7A\u1E7C\u1E7E\u1E80\u1E82\u1E84\u1E86\u1E88\u1E8A\u1E8C\u1E8E\u1E90\u1E92\u1E94\u1E9E\u1EA0\u1EA2\u1EA4\u1EA6\u1EA8\u1EAA\u1EAC\u1EAE\u1EB0\u1EB2\u1EB4\u1EB6\u1EB8\u1EBA\u1EBC\u1EBE\u1EC0\u1EC2\u1EC4\u1EC6\u1EC8\u1ECA\u1ECC\u1ECE\u1ED0\u1ED2\u1ED4\u1ED6\u1ED8\u1EDA\u1EDC\u1EDE\u1EE0\u1EE2\u1EE4\u1EE6\u1EE8\u1EEA\u1EEC\u1EEE\u1EF0\u1EF2\u1EF4\u1EF6\u1EF8\u1EFA\u1EFC\u1EFE\u1F08-\u1F0F\u1F18-\u1F1D\u1F28-\u1F2F\u1F38-\u1F3F\u1F48-\u1F4D\u1F59\u1F5B\u1F5D\u1F5F\u1F68-\u1F6F\u1FB8-\u1FBB\u1FC8-\u1FCB\u1FD8-\u1FDB\u1FE8-\u1FEC\u1FF8-\u1FFB\u2102\u2107\u210B-\u210D\u2110-\u2112\u2115\u2119-\u211D\u2124\u2126\u2128\u212A-\u212D\u2130-\u2133\u213E-\u213F\u2145\u2183\u2C00-\u2C2E\u2C60\u2C62-\u2C64\u2C67\u2C69\u2C6B\u2C6D-\u2C70\u2C72\u2C75\u2C7E-\u2C80\u2C82\u2C84\u2C86\u2C88\u2C8A\u2C8C\u2C8E\u2C90\u2C92\u2C94\u2C96\u2C98\u2C9A\u2C9C\u2C9E\u2CA0\u2CA2\u2CA4\u2CA6\u2CA8\u2CAA\u2CAC\u2CAE\u2CB0\u2CB2\u2CB4\u2CB6\u2CB8\u2CBA\u2CBC\u2CBE\u2CC0\u2CC2\u2CC4\u2CC6\u2CC8\u2CCA\u2CCC\u2CCE\u2CD0\u2CD2\u2CD4\u2CD6\u2CD8\u2CDA\u2CDC\u2CDE\u2CE0\u2CE2\u2CEB\u2CED\u2CF2\uA640\uA642\uA644\uA646\uA648\uA64A\uA64C\uA64E\uA650\uA652\uA654\uA656\uA658\uA65A\uA65C\uA65E\uA660\uA662\uA664\uA666\uA668\uA66A\uA66C\uA680\uA682\uA684\uA686\uA688\uA68A\uA68C\uA68E\uA690\uA692\uA694\uA696\uA698\uA69A\uA722\uA724\uA726\uA728\uA72A\uA72C\uA72E\uA732\uA734\uA736\uA738\uA73A\uA73C\uA73E\uA740\uA742\uA744\uA746\uA748\uA74A\uA74C\uA74E\uA750\uA752\uA754\uA756\uA758\uA75A\uA75C\uA75E\uA760\uA762\uA764\uA766\uA768\uA76A\uA76C\uA76E\uA779\uA77B\uA77D-\uA77E\uA780\uA782\uA784\uA786\uA78B\uA78D\uA790\uA792\uA796\uA798\uA79A\uA79C\uA79E\uA7A0\uA7A2\uA7A4\uA7A6\uA7A8\uA7AA-\uA7AE\uA7B0-\uA7B4\uA7B6\uA7B8\uA7BA\uA7BC\uA7BE\uA7C2\uA7C4-\uA7C6\uFF21-\uFF3A]|(?:\uD801[\uDC00-\uDC27\uDCB0-\uDCD3]|\uD803[\uDC80-\uDCB2]|\uD806[\uDCA0-\uDCBF]|\uD81B[\uDE40-\uDE5F]|\uD835[\uDC00-\uDC19\uDC34-\uDC4D\uDC68-\uDC81\uDC9C\uDC9E-\uDC9F\uDCA2\uDCA5-\uDCA6\uDCA9-\uDCAC\uDCAE-\uDCB5\uDCD0-\uDCE9\uDD04-\uDD05\uDD07-\uDD0A\uDD0D-\uDD14\uDD16-\uDD1C\uDD38-\uDD39\uDD3B-\uDD3E\uDD40-\uDD44\uDD46\uDD4A-\uDD50\uDD6C-\uDD85\uDDA0-\uDDB9\uDDD4-\uDDED\uDE08-\uDE21\uDE3C-\uDE55\uDE70-\uDE89\uDEA8-\uDEC0\uDEE2-\uDEFA\uDF1C-\uDF34\uDF56-\uDF6E\uDF90-\uDFA8\uDFCA]|\uD83A[\uDD00-\uDD21]))

Querying the UCD database of Unicode 12, \p{Ll} generates 2,151 code points.

Converting to UTF-16 yields the class construct equivalency. 

(?:[\u0061-\u007A\u00B5\u00DF-\u00F6\u00F8-\u00FF\u0101\u0103\u0105\u0107\u0109\u010B\u010D\u010F\u0111\u0113\u0115\u0117\u0119\u011B\u011D\u011F\u0121\u0123\u0125\u0127\u0129\u012B\u012D\u012F\u0131\u0133\u0135\u0137-\u0138\u013A\u013C\u013E\u0140\u0142\u0144\u0146\u0148-\u0149\u014B\u014D\u014F\u0151\u0153\u0155\u0157\u0159\u015B\u015D\u015F\u0161\u0163\u0165\u0167\u0169\u016B\u016D\u016F\u0171\u0173\u0175\u0177\u017A\u017C\u017E-\u0180\u0183\u0185\u0188\u018C-\u018D\u0192\u0195\u0199-\u019B\u019E\u01A1\u01A3\u01A5\u01A8\u01AA-\u01AB\u01AD\u01B0\u01B4\u01B6\u01B9-\u01BA\u01BD-\u01BF\u01C6\u01C9\u01CC\u01CE\u01D0\u01D2\u01D4\u01D6\u01D8\u01DA\u01DC-\u01DD\u01DF\u01E1\u01E3\u01E5\u01E7\u01E9\u01EB\u01ED\u01EF-\u01F0\u01F3\u01F5\u01F9\u01FB\u01FD\u01FF\u0201\u0203\u0205\u0207\u0209\u020B\u020D\u020F\u0211\u0213\u0215\u0217\u0219\u021B\u021D\u021F\u0221\u0223\u0225\u0227\u0229\u022B\u022D\u022F\u0231\u0233-\u0239\u023C\u023F-\u0240\u0242\u0247\u0249\u024B\u024D\u024F-\u0293\u0295-\u02AF\u0371\u0373\u0377\u037B-\u037D\u0390\u03AC-\u03CE\u03D0-\u03D1\u03D5-\u03D7\u03D9\u03DB\u03DD\u03DF\u03E1\u03E3\u03E5\u03E7\u03E9\u03EB\u03ED\u03EF-\u03F3\u03F5\u03F8\u03FB-\u03FC\u0430-\u045F\u0461\u0463\u0465\u0467\u0469\u046B\u046D\u046F\u0471\u0473\u0475\u0477\u0479\u047B\u047D\u047F\u0481\u048B\u048D\u048F\u0491\u0493\u0495\u0497\u0499\u049B\u049D\u049F\u04A1\u04A3\u04A5\u04A7\u04A9\u04AB\u04AD\u04AF\u04B1\u04B3\u04B5\u04B7\u04B9\u04BB\u04BD\u04BF\u04C2\u04C4\u04C6\u04C8\u04CA\u04CC\u04CE-\u04CF\u04D1\u04D3\u04D5\u04D7\u04D9\u04DB\u04DD\u04DF\u04E1\u04E3\u04E5\u04E7\u04E9\u04EB\u04ED\u04EF\u04F1\u04F3\u04F5\u04F7\u04F9\u04FB\u04FD\u04FF\u0501\u0503\u0505\u0507\u0509\u050B\u050D\u050F\u0511\u0513\u0515\u0517\u0519\u051B\u051D\u051F\u0521\u0523\u0525\u0527\u0529\u052B\u052D\u052F\u0560-\u0588\u10D0-\u10FA\u10FD-\u10FF\u13F8-\u13FD\u1C80-\u1C88\u1D00-\u1D2B\u1D6B-\u1D77\u1D79-\u1D9A\u1E01\u1E03\u1E05\u1E07\u1E09\u1E0B\u1E0D\u1E0F\u1E11\u1E13\u1E15\u1E17\u1E19\u1E1B\u1E1D\u1E1F\u1E21\u1E23\u1E25\u1E27\u1E29\u1E2B\u1E2D\u1E2F\u1E31\u1E33\u1E35\u1E37\u1E39\u1E3B\u1E3D\u1E3F\u1E41\u1E43\u1E45\u1E47\u1E49\u1E4B\u1E4D\u1E4F\u1E51\u1E53\u1E55\u1E57\u1E59\u1E5B\u1E5D\u1E5F\u1E61\u1E63\u1E65\u1E67\u1E69\u1E6B\u1E6D\u1E6F\u1E71\u1E73\u1E75\u1E77\u1E79\u1E7B\u1E7D\u1E7F\u1E81\u1E83\u1E85\u1E87\u1E89\u1E8B\u1E8D\u1E8F\u1E91\u1E93\u1E95-\u1E9D\u1E9F\u1EA1\u1EA3\u1EA5\u1EA7\u1EA9\u1EAB\u1EAD\u1EAF\u1EB1\u1EB3\u1EB5\u1EB7\u1EB9\u1EBB\u1EBD\u1EBF\u1EC1\u1EC3\u1EC5\u1EC7\u1EC9\u1ECB\u1ECD\u1ECF\u1ED1\u1ED3\u1ED5\u1ED7\u1ED9\u1EDB\u1EDD\u1EDF\u1EE1\u1EE3\u1EE5\u1EE7\u1EE9\u1EEB\u1EED\u1EEF\u1EF1\u1EF3\u1EF5\u1EF7\u1EF9\u1EFB\u1EFD\u1EFF-\u1F07\u1F10-\u1F15\u1F20-\u1F27\u1F30-\u1F37\u1F40-\u1F45\u1F50-\u1F57\u1F60-\u1F67\u1F70-\u1F7D\u1F80-\u1F87\u1F90-\u1F97\u1FA0-\u1FA7\u1FB0-\u1FB4\u1FB6-\u1FB7\u1FBE\u1FC2-\u1FC4\u1FC6-\u1FC7\u1FD0-\u1FD3\u1FD6-\u1FD7\u1FE0-\u1FE7\u1FF2-\u1FF4\u1FF6-\u1FF7\u210A\u210E-\u210F\u2113\u212F\u2134\u2139\u213C-\u213D\u2146-\u2149\u214E\u2184\u2C30-\u2C5E\u2C61\u2C65-\u2C66\u2C68\u2C6A\u2C6C\u2C71\u2C73-\u2C74\u2C76-\u2C7B\u2C81\u2C83\u2C85\u2C87\u2C89\u2C8B\u2C8D\u2C8F\u2C91\u2C93\u2C95\u2C97\u2C99\u2C9B\u2C9D\u2C9F\u2CA1\u2CA3\u2CA5\u2CA7\u2CA9\u2CAB\u2CAD\u2CAF\u2CB1\u2CB3\u2CB5\u2CB7\u2CB9\u2CBB\u2CBD\u2CBF\u2CC1\u2CC3\u2CC5\u2CC7\u2CC9\u2CCB\u2CCD\u2CCF\u2CD1\u2CD3\u2CD5\u2CD7\u2CD9\u2CDB\u2CDD\u2CDF\u2CE1\u2CE3-\u2CE4\u2CEC\u2CEE\u2CF3\u2D00-\u2D25\u2D27\u2D2D\uA641\uA643\uA645\uA647\uA649\uA64B\uA64D\uA64F\uA651\uA653\uA655\uA657\uA659\uA65B\uA65D\uA65F\uA661\uA663\uA665\uA667\uA669\uA66B\uA66D\uA681\uA683\uA685\uA687\uA689\uA68B\uA68D\uA68F\uA691\uA693\uA695\uA697\uA699\uA69B\uA723\uA725\uA727\uA729\uA72B\uA72D\uA72F-\uA731\uA733\uA735\uA737\uA739\uA73B\uA73D\uA73F\uA741\uA743\uA745\uA747\uA749\uA74B\uA74D\uA74F\uA751\uA753\uA755\uA757\uA759\uA75B\uA75D\uA75F\uA761\uA763\uA765\uA767\uA769\uA76B\uA76D\uA76F\uA771-\uA778\uA77A\uA77C\uA77F\uA781\uA783\uA785\uA787\uA78C\uA78E\uA791\uA793-\uA795\uA797\uA799\uA79B\uA79D\uA79F\uA7A1\uA7A3\uA7A5\uA7A7\uA7A9\uA7AF\uA7B5\uA7B7\uA7B9\uA7BB\uA7BD\uA7BF\uA7C3\uA7FA\uAB30-\uAB5A\uAB60-\uAB67\uAB70-\uABBF\uFB00-\uFB06\uFB13-\uFB17\uFF41-\uFF5A]|(?:\uD801[\uDC28-\uDC4F\uDCD8-\uDCFB]|\uD803[\uDCC0-\uDCF2]|\uD806[\uDCC0-\uDCDF]|\uD81B[\uDE60-\uDE7F]|\uD835[\uDC1A-\uDC33\uDC4E-\uDC54\uDC56-\uDC67\uDC82-\uDC9B\uDCB6-\uDCB9\uDCBB\uDCBD-\uDCC3\uDCC5-\uDCCF\uDCEA-\uDD03\uDD1E-\uDD37\uDD52-\uDD6B\uDD86-\uDD9F\uDDBA-\uDDD3\uDDEE-\uDE07\uDE22-\uDE3B\uDE56-\uDE6F\uDE8A-\uDEA5\uDEC2-\uDEDA\uDEDC-\uDEE1\uDEFC-\uDF14\uDF16-\uDF1B\uDF36-\uDF4E\uDF50-\uDF55\uDF70-\uDF88\uDF8A-\uDF8F\uDFAA-\uDFC2\uDFC4-\uDFC9\uDFCB]|\uD83A[\uDD22-\uDD43]))

Note that a regex implementation of \p{Lu} or \p{Pl} actually calls a
non standard function to test the value.

The character classes shown here are done differently and are linear, standard
and pretty slow, when jammed into mostly a single class.

Some insight on how a Regex engine (in general) implements Unicode Property Classes:

Examine these performance characteristics between the property
and the class block (like above) 

Regex1:  LONG CLASS 
< none >
Completed iterations:   50  /  50     ( x 1 )
Matches found per iteration:   1788
Elapsed Time:    0.73 s,   727.58 ms,   727584 µs
Matches per sec:   122,872


Regex2:   \p{Lu}
Options:  < ICU - none >
Completed iterations:   50  /  50     ( x 1 )
Matches found per iteration:   1788
Elapsed Time:    0.07 s,   65.32 ms,   65323 µs
Matches per sec:   1,368,583

Wow what a difference !!

Lets see how Properties might be implemented

Array of Pointers [ 10FFFF ] where each index is is a Code Point

  • Each pointer in the Array is to a structure of classification.

    • A Classification structure contains fixed field elemets.
      Some are NULL and do not pertain.
      Some contain category classifications.

      Example : General Category
      This is a bitmapped element that uses 17 out of 64 bits.
      Whatever this Code Point supports has bit(s) set as a mask.

      -Close_Punctuation
      -Connector_Punctuation
      -Control
      -Currency_Symbol
      -Dash_Punctuation
      -Decimal_Number
      -Enclosing_Mark
      -Final_Punctuation
      -Format
      -Initial_Punctuation
      -Letter_Number
      -Line_Separator
      -Lowercase_Letter
      -Math_Symbol
      -Modifier_Letter
      -Modifier_Symbol
      -Nonspacing_Mark
      -Open_Punctuation
      -Other_Letter
      -Other_Number
      -Other_Punctuation
      -Other_Symbol
      -Paragraph_Separator
      -Private_Use
      -Space_Separator
      -Spacing_Mark
      -Surrogate
      -Titlecase_Letter
      -Unassigned
      -Uppercase_Letter

When a regex is parsed with something like this \p{Lu} it
is translated directly into

  • Classification Structure element offset : General Category
  • A check of that element for bit item : Uppercase_Letter

Another example, when a regex is parsed with punctuation property \p{P} it
is translated into

  • Classification Structure element offset : General Category

  • A check of that element for any of these items bits, which are joined into a mask :

    -Close_Punctuation
    -Connector_Punctuation
    -Dash_Punctuation
    -Final_Punctuation
    -Initial_Punctuation
    -Open_Punctuation
    -Other_Punctuation

The offset and bit or bit(mask) are stored as a regex step for that property.

The lookup table is created once for all Unicode Code Points using this array.

When a character is checked, it is as simple as using the CP as an index into this array and checking the Classification Structure's specific element for that bit(mask).

This structure is expandable and indirect to provide much more complex look ups. This is just a simple example.

Compare that direct lookup with a character class search :

All classes are a linear list of items searched from left to right.
In this comparison, given our target string contains only the complete Upper Case Unicode Letters only, the law of averages would predict that half of the items in the class would have to be ranged checked to find a match.

This is a huge disadvantage in performance.

However, if the lookup tables are not there or are not up to date with the latest Unicode release (12 as of this date)
then this would be the only way.

In fact, it is mostly the only way to get the complete Emoji
characters as there is no specific property (or reasoning) to their assignment.

2
votes

You can also use:

function myFunction() {
  var str = "xq234"; 
  var allowChars = "^[a-zA-ZÀ-ÿ]+$";
  var res = str.match(allowChars);
  if(!str.match(allowChars)){
    res="true";
  }
  else {
    res="false";
  }
  document.getElementById("demo").innerHTML = res;