Re: [FleXML-Users] generated parser declaration

[William F. D. <wil...@th...>]

On Tue, 2005-02-15 at 02:26, Martin Quinson wrote:
> On Mon, Jan 24, 2005 at 05:06:27PM -0500, Dowling, William (Will) (TS USA) wrote:
> > One limitation of the flexml-generated parser is that its prototype is
> > fixed within flexml:
> >   int yylex()
> > In order to pass in a parameter to the generated parser, I had to resort
> > to a flex command line that contained this (I am generating C++ code,
> > hence the class declaration)
> > 
> > -PLinksXML \
> > -DYY_DECL='"class LinksAPIStart; static LinksAPIStart *
> > private_Start_ptr; int LinksXMLlex(LinksAPIStart *LinksAPIStart_ptr)"' \
> > -DYY_USER_INIT='"private_Start_ptr=LinksAPIStart_ptr;"'
> > 
> > This trick allows me to refer to the parameter passed into the parser
> > (LinksAPIStart_ptr) using the name private_Start_ptr in my .act file.
> > [...]
> 
> [...] we also want to embeed several parsers in the same
> code, and that I was thinking about implementing the -P flag to flexml.
> 
> It does not look really related to your issue [...]

I think it is somewhat related; -P allows you to change the name of the
generated parser, as does modifying YY_DECL.  (-P also privatizes other
identifiers, which YY_DECL does not.)  YY_DECL also allows you to change
the signature (params and return type), which -P does not.  This part of
the design of flex is not as orthogonal as it could be.

Maybe a YY_DECL (and other user-settable #defines) should be passed
through from flexml into the generated flex input file?

Will

-- 
William F. Dowling
Thomson/ISI (www.thomsonisi.com)
215-386-0100 x-1156

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