Neat! Your parser [1] almost has a similar issue because a comm could contain parenthesis, e.g., `foo) R 123 456`. But since a comm is limited to 64 bytes, I don't think it is possible to fit a fully matching string inside of the comm before the closing parent after the comm, which would thus make your regexp fail to match.

[1] https://github.com/kellyjonbrazil/jc/blob/master/jc/parsers/...