Re: SableCC-2.6 bug?

[Amancio Hasty <hasty@rah.star-gate.com>]

Hi!

So how would one express something like a URL (RFC 1738) using SableCC?

	Tnks!
	Amancio

> Amancio Hasty wrote:
> > 
> > ...
> > It appears that SableCC gets confused if the production rule
> > includes a token who is a proper subset of another token in the
> > rule.
> 
> SableCC is behaving properly. Let me restate that SableCC lexers match
> the longest token, and then, if there are two tokens that can be
> matched, it chooses the first listed token in the Tokens section.
> 
> This means, concretely, that "aaa" is matched as a TAlpa, because "aaa"
> could be both a TAlpa or a TLetter. But TAlpa is listed before TLetter,
> so TLetter is matched.
> 
> It is important to see that the lexer operates independently from the
> parser. This means that the lexer won't look at the grammar and see that
> a TLetter is expected and try to match it.
> 
> It is also important to note that TLetter will never be matched, because
> TAlpa completely hides it.
> 
> Have fun!
> 
> Etienne