From: Arkadiy Vertleyb (vertleyb_at_[hidden])
Date: 2004-05-05 11:08:29
"Reece Dunn" <msclrhd_at_[hidden]> wrote
> One question though: I have a parser where I have created several external
> grammars to help modularize the grammar and employ the trick suggested in
> the techniques section (c.f. sub-grammar):
>
> using namespace boost::spirit;
>
> struct identifier_parser: public sub_grammar< identifier_parser >
> {
> public:
> typedef sequence_t
> <
> alternative< alpha_parser, chlit<> >,
> kleene_alternative_t< alnum_parser, chlit<> >::type
> >::type
> start_t;
> public:
> start_t start;
> public:
> inline identifier_parser():
> start
> (
> ( alpha_p | '_' ) >> *( alnum_p | '_' )
> )
> {
> }
> } identifier;
>
> NOTE: This is using various type construction helpers.
>
> Once you have a (sub-)rule like this, you can use it like:
>
> rule_t<ScannerT> tagName = !( identifier >> ':' ) >> identifier;
>
> I was wondering if this would cause any major problems when implemented
with
> the typeof/auto hack (since it could then be implemented as a grammar).
I think you would just have to register your identifier_parser class. The
typeof system then would treat it as an atom and not care what is behind it.
Regards,
Arkadiy