return reduceRight.call(subjectString, function(trimmed, character) {
if (matchWhitespace && includes(whitespaceString, character)) {
return trimmed;
}
matchWhitespace = false;
return character + trimmed;
}, '');
/**
* Append flag to a regular expression.
*
* @ignore
* @param {RegExp} pattern The pattern to coerce.
* @param {string} appendFlag The flag to append to regular expression.
* @return {RegExp} The regular expression with added flag.
*/
export default function appendFlagToRegExp(pattern, appendFlag) {
const regularExpressionFlags = getRegExpFlags(pattern);
if (!includes(regularExpressionFlags, appendFlag)) {
return new RegExp(pattern.source, regularExpressionFlags + appendFlag);
}
return pattern;
}