Bump to v4.0.0.

internal/stringToArray.js

@@ -0,0 +1,36 @@
+/** Used to compose unicode character classes. */
+var rsAstralRange = '\\ud800-\\udfff',
+    rsComboRange = '\\u0300-\\u036f\\ufe20-\\ufe23',
+    rsVarRange = '\\ufe0e\\ufe0f';
+
+/** Used to compose unicode capture groups. */
+var rsAstral = '[' + rsAstralRange + ']',
+    rsCombo = '[' + rsComboRange + ']',
+    rsModifier = '(?:\\ud83c[\\udffb-\\udfff])',
+    rsNonAstral = '[^' + rsAstralRange + ']',
+    rsRegional = '(?:\\ud83c[\\udde6-\\uddff]){2}',
+    rsSurrPair = '[\\ud800-\\udbff][\\udc00-\\udfff]',
+    rsZWJ = '\\u200d';
+
+/** Used to compose unicode regexes. */
+var reOptMod = rsModifier + '?',
+    rsOptVar = '[' + rsVarRange + ']?',
+    rsOptJoin = '(?:' + rsZWJ + '(?:' + [rsNonAstral, rsRegional, rsSurrPair].join('|') + ')' + rsOptVar + reOptMod + ')*',
+    rsSeq = rsOptVar + reOptMod + rsOptJoin,
+    rsSymbol = '(?:' + [rsNonAstral + rsCombo + '?', rsCombo, rsRegional, rsSurrPair, rsAstral].join('|') + ')';
+
+/** Used to match [string symbols](https://mathiasbynens.be/notes/javascript-unicode). */
+var reComplexSymbol = RegExp(rsSymbol + rsSeq, 'g');
+
+/**
+ * Converts `string` to an array.
+ *
+ * @private
+ * @param {string} string The string to convert.
+ * @returns {Array} Returns the converted array.
+ */
+function stringToArray(string) {
+  return string.match(reComplexSymbol);
+}
+
+module.exports = stringToArray;