RE: [Boost-users] Re: Tweaking the Skip Parser, was RE: Spirit 1.6 with VC6

From: Mark Storer (MStorer_at_[hidden])
Date: 2004-06-25 18:31:55

Okay.  Problem solved.  The answer was indeed inside #scanner_business.  Rules make for picky parsers.  So I used a grammar<> and it compiled just fine.  Now if I can just get it to WORK.  ;)

Whoops.  Infinite recursion.  Back to the drawing board... but at least now I don't need "*comment" sprinkled liberally throughout my rules.

--Mark Storer
  Senior Software Engineer
  Verity, Inc.

> -----Original Message-----
> From: boost-users-bounces_at_[hidden]
> [mailto:boost-users-bounces_at_[hidden]]On Behalf Of Jeff Flinn
> Sent: Friday, June 25, 2004 10:46 AM
> To: boost-users_at_[hidden]
> Subject: [Boost-users] Re: Tweaking the Skip Parser,was RE: Spirit 1.6
> with VC6
> 
> 
> Take a look at:
> 
>     http://www.boost.org/libs/spirit/doc/faq.html#scanner_business
> 
> You don't want the skip parser to be a phrase level scanner.
> 
>  parse(str, rules, space_p | comment_p( "/*", "*/" ) | 
> comment_p( "//" ) )
> 
> may work for you?
> 
> Jeff F
> 
> "Mark Storer" <MStorer_at_[hidden]> wrote in message
> news:076D1E704127414E9FEAFFC31F66C9472739CD_at_vrsdex1.verity.com...
> > > No chance of switching to 7.1? :-)
> >
> > Things are looking up.  We just did a project-wide upgrade 
> to... VC7.1.
> Problem solved.  I'm now merrily writing rules for my 
> JavaScript parser.  It
> doesn't have to support the whole language (not for a while, 
> maybe never), I
> just need to be able to parse out the names and locations of all the
> functions in a file.  It's for a JavaScript editor built into 
> one of our
> products, and later we'll be adding auto-completion.  That'll 
> require a more
> thorough parser, but for now, I'm just after funciton locations.
> >
> > So far so good... though I'll undoubtedly be quite familiar with the
> BOOST_SPIRIT_DEBUG* macros before I'm done.
> >
> > I've got another Spirit question:  I've been adding 
> "*comment" throughout
> the rules and it's getting tiresome:
> >
> >   rule<phrase_scanner_t> blockComment = comment_p( "/*", "*/" );
> >   rule<phrase_scanner_t> lineComment  = comment_p( "//" );
> >   rule<phrase_scanner_t> comment      = blockComment | lineComment;
> >
> > Spraying the "comment" rule liberally through my rules is 
> an option...
> >
> >   rule<phrase_scanner_t> codeBlock    = ch_p('{') >> 
> *(comment | codeBlock
> | ~ch_p('}')) >> ch_p('}');
> >
> > ... but not an appealing one.  This becomes particularly 
> true once I start
> working on the auto-completion parser.
> >
> >   It just occured to me that if the skip parser ate 
> comments for me, it
> would greatly simplify my rules.  I'd like to tweak the skip 
> parser so it
> skips over my "comment" rule as well as white space.  I just 
> took a stab at
> this, but didn't get very far.  I tried:
> >
> > parse(str, rules, space_p | comment)
> >
> > but that resulted in a compiler error.  7.1's errors are 
> MUCH easier to
> read that 6's.  I'm going to like this new compiler.
> >
> > 
> C:\SDKs\boost_1_31_0\boost\spirit\core\non_terminal\impl\rule.
> ipp(190):
> error C2664:
> 'boost::spirit::impl::abstract_parser<ScannerT,AttrT>::do_pars
> e_virtual' :
> cannot convert parameter 1 from 'const scanner_t' to 'const
> boost::spirit::rule<T0>::scanner_t &'
> >         with
> >         [
> >
> ScannerT=boost::spirit::rule<boost::spirit::phrase_scanner_t>:
> :scanner_t,
> >
> AttrT=boost::spirit::rule<boost::spirit::phrase_scanner_t>::attr_t
> >         ]
> >         and
> >         [
> >             T0=boost::spirit::phrase_scanner_t
> >         ]
> >
> > Pointing me to the relevant section of the docs is an 
> acceptable answer,
> though I wouldn't mind a little more info than that. ;)
> >
> > I'll keep plugging away.  If I come up with an answer, I'll 
> post it to the
> list.  I'd expect this to be useful to other beginners at the 
> very least.
> >
> > --Mark Storer
> >   Senior Software Engineer
> >   Verity, Inc.
> 
> 
> 
> _______________________________________________
> Boost-users mailing list
> Boost-users_at_[hidden]
> http://lists.boost.org/mailman/listinfo.cgi/boost-users
>