Re: [boost] Async xpressive, regex and spirit

From: Scott Woods (scottw_at_[hidden])
Date: 2005-09-15 17:18:40

----- Original Message -----
From: "Felipe Magno de Almeida" <felipe.m.almeida_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Friday, September 16, 2005 9:40 AM
Subject: Re: [boost] Async xpressive, regex and spirit

> > > IMO, it would be needed the possibility to have more than one grammar,
> > > one for success and another for failure(Would be interesting to have
> > > the possibility for more than two), until no-one has a match continue
> > > to wait for more data...
> > >
> >
> > Sorry. Don't follow the duplex grammar idea.
>
> Imagine a SMTP protocol, it has two or more responses for a command,
> being from success, warning and completely failure. That way is
> necessary 3 grammars, one for each. If nothing matched, then we
> probably have a real problem. But one of the three should be matched,
> in genereal.
>

I suspect we have different understandings of what a grammar is. Other
possible misunderstandings make this confusing, e.g. software that receives
SMTP responses never receives the related commands (client vs server) so a
grammar that spans these domains does not make sense? Also, are you
applying language technology (i.e. grammars) to the overall processing of
protocol signals/messages?

While I find the idea compelling (my first use of yacc a long time ago was
for exactly this) it may not be the most appropriate, e.g. FSMs are "lingua
franca" in telephony protocols whereas grammars do not get a mention.

But grammars are cool :-)

Cheers.