Re: [Boost-users] [spirit] parsing keyword or identifier

Subject: Re: [Boost-users] [spirit] parsing keyword or identifier
From: Hartmut Kaiser (hartmut.kaiser_at_[hidden])
Date: 2011-05-02 22:18:41

> I have what I think is a simple problem:  I'm trying to parse IES files,
> and there is a line that can have three options:
> 
> TILT=NONE
> -or-
> TILT=INCLUDE
> -or-
> TILT=<filename>
> 
> The way I'm trying to parse this line is:
> 
> 
>    // in the case of TILT=INCLUDE or TILT=<filename>
>     int lampToLuminaireGeom;
>     int numPairsWithMulFactors = 0;
> 
>    std::string tiltFileName;
> 
>     BOOST_AUTO(keywordSym, (qi::lit("NONE") | qi::lit("INCLUDE")));
>     BOOST_AUTO(fileName, *char_ - keywordSym);

Spirit grammars are still C++ and still obey the default C++ operator
preferences. Use this instead:

    BOOST_AUTO(fileName, *(char_ - keywordSym));

and it will work.

>     BOOST_AUTO(initial, ( "TILT" >> char_('=') >>
>                           ( "NONE" |
>                             ( "INCLUDE" >>
>                               int_[ref(lampToLuminaireGeom) = _1] >>
>                               int_[ref(numPairsWithMulFactors) = _1] ) |
>                             fileName[ref(tiltFileName)] ) ) );
> 
>     if(!phrase_parse(first, last, initial, space)) {
>         return IES_INVALID;
>     }
> 
> The code works with NONE or INCLUDE, but not with files.  As far as I
> know, there are no real restrictions on the filenames.  At this point, the
> code posted above can't even get simple file names, but really I think
> what is required is that I grab anything non-whitespace after the '='
> until it reaches an EOL.
> 
> Can anyone provide some insight about what I may be doing wrong?

HTH
Regards Hartmut
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