*/
public static function lex(string $content)
{
static $regex;
if ($regex === null) {
$regex = '(('.\implode(')|(', self::PATTERNS).'))A';
}
$offset = 0;
while (isset($content[$offset])) {
if (!\preg_match($regex, $content, $matches, 0, $offset)) {
throw new \Error(\sprintf('Lexer encountered unexpected character [%s].', $content[$offset]));
}
$offset += \strlen($matches[0]);
yield $matches[0];
}
}
}