/**
* Returns a value indicating if a token of this type can be matched at
* the start of the subject string.
* @param string the subject string
* @return mixed match at the start of the string or false if no match
*/
public static function isa($subject)
{
if (empty(self::$regex)) {
self::$regex = str_replace('{CSS_COLOURS}', join('|', array_reverse(array_keys(self::$svgColours))), self::MATCH);
}
return preg_match(self::$regex, strtolower($subject), $matches) ? $matches[0] : false;
}
