1 /** Used to compose unicode character classes. */
2 var rsAstralRange = '\\ud800-\\udfff',
3 rsComboMarksRange = '\\u0300-\\u036f\\ufe20-\\ufe23',
4 rsComboSymbolsRange = '\\u20d0-\\u20f0',
5 rsVarRange = '\\ufe0e\\ufe0f';
7 /** Used to compose unicode capture groups. */
8 var rsAstral = '[' + rsAstralRange + ']',
9 rsCombo = '[' + rsComboMarksRange + rsComboSymbolsRange + ']',
10 rsFitz = '\\ud83c[\\udffb-\\udfff]',
11 rsModifier = '(?:' + rsCombo + '|' + rsFitz + ')',
12 rsNonAstral = '[^' + rsAstralRange + ']',
13 rsRegional = '(?:\\ud83c[\\udde6-\\uddff]){2}',
14 rsSurrPair = '[\\ud800-\\udbff][\\udc00-\\udfff]',
17 /** Used to compose unicode regexes. */
18 var reOptMod = rsModifier + '?',
19 rsOptVar = '[' + rsVarRange + ']?',
20 rsOptJoin = '(?:' + rsZWJ + '(?:' + [rsNonAstral, rsRegional, rsSurrPair].join('|') + ')' + rsOptVar + reOptMod + ')*',
21 rsSeq = rsOptVar + reOptMod + rsOptJoin,
22 rsSymbol = '(?:' + [rsNonAstral + rsCombo + '?', rsCombo, rsRegional, rsSurrPair, rsAstral].join('|') + ')';
24 /** Used to match [string symbols](https://mathiasbynens.be/notes/javascript-unicode). */
25 var reComplexSymbol = RegExp(rsFitz + '(?=' + rsFitz + ')|' + rsSymbol + rsSeq, 'g');
27 /** Used to detect strings with [zero-width joiners or code points from the astral planes](http://eev.ee/blog/2015/09/12/dark-corners-of-unicode/). */
28 var reHasComplexSymbol = RegExp('[' + rsZWJ + rsAstralRange + rsComboMarksRange + rsComboSymbolsRange + rsVarRange + ']');
31 * Gets the number of symbols in `string`.
34 * @param {string} string The string to inspect.
35 * @returns {number} Returns the string size.
37 function stringSize(string) {
38 if (!(string && reHasComplexSymbol.test(string))) {
41 var result = reComplexSymbol.lastIndex = 0;
42 while (reComplexSymbol.test(string)) {
48 module.exports = stringSize;