Re: [Boost-users] Spirit.Qi : forfait !

Subject: Re: [Boost-users] Spirit.Qi : forfait !
From: OvermindDL1 (overminddl1_at_[hidden])
Date: 2010-04-16 20:35:18

On Fri, Apr 16, 2010 at 10:07 AM, Michele Caini <michele.caini_at_[hidden]> wrote:
> Il 16/04/2010 17:13, Hartmut Kaiser ha scritto:
>> Michael,
>>
>> I really would like to help but I can't compile your example (parser.h and ../exception/sapecngexception.h is missing). And even if I could, it is always the best if you try to minimize the code you send to expose exactly the problem you're having. It's very difficult to understand such complex programs as yours without investing a significant amount of time.
>>
>> Regards Hartmut
>
>
> Hi dear,
> thank you very much.
> Parser is part of a more complex software so it is not so easy to
> extract it from the software. However, if you can, I'd like to
> understand with your help steps to do.
>
> Suppose our grammatic, like this, very simple (I put into quotes literal
> component, like ".OUT", ok?):
>
>
> Â out := ".OUT" integer
> Â end := ".END"
>
> Â cmp := "R"(char)* integer integer double bool
> Â cmp := "L"(char)* integer integer double bool
>
> Â comment := "#"(char*) // it goes to the end of line
>
> Â start := (comment)*
> Â  Â  Â  Â  Â  (cmp)+
> Â  Â  Â  Â  Â  out
> Â  Â  Â  Â  Â  end
>
>
> That's all, if I'm not clear (this is not BNF, and this is not Spirit
> like, I know!), please ask me.
>
> Ok, go on.
> I'd like to fill structs like this (adapted by BOOST_FUSION_ADAPT_STRUCT
> macro, quite simple to do):
>
>
> Â struct cmp_s {
> Â  Â int id;
> Â  Â std::string name;
> Â  Â int va, vb;
> Â  Â double val;
> Â  Â bool sym;
> Â };
>
> Â struct main_s {
> Â  Â std::vector<std::string> comments;
> Â  Â std::vector<cmp_s> cmps;
> Â  Â int out;
> Â };
>
>
> Suppose id comes from that symbols table (real table is quite more
> complex but this is a foo-example, is it?):
>
>
> Â struct table_ : boost::spirit::qi::symbols< char, int >
> Â {
> Â  Â table_()
> Â  Â {
> Â  Â  Â add
> Â  Â  Â  Â ("R", 1)
> Â  Â  Â  Â ("L", 2)
> Â  Â  Â ;
> Â  Â }
> Â };
>
>
> That's all. Follows my grammar:
>
>
> template < typename It >
> struct parser : boost::spirit::qi::grammar
> Â < It, main_c(), boost::spirit::qi::ascii::space_type >
> {
>
> Â typedef
> Â boost::spirit::qi::ascii::space_type
> Â space_type;
>
> Â parser(std::ostream& err): parser::base_type(start, "start")
> Â {
> Â  Â using namespace boost::spirit;
> Â  Â using namespace boost::phoenix;
>
> Â  Â comment %= qi::lexeme['#' >> +(ascii::char_)];
>
> Â  Â selm = Â qi::char_("RL")
> Â  Â  Â  Â  Â  Â  Â [at_c<0>(_val) = (table_() << _1), at_c<1>(_val) = _1]
> Â  Â  Â  Â >> Â *qi::char_("_a-zA-Z0-9") Â [at_c<1>(_val) += _1]
> Â  Â  Â  Â >> Â qi::int_ Â  Â  Â  Â  Â  Â  Â  Â  Â [at_c<2>(_val) = _1]
> Â  Â  Â  Â >> Â qi::int_ Â  Â  Â  Â  Â  Â  Â  Â  Â [at_c<3>(_val) = _1]
> Â  Â  Â  Â >> Â qi::double_ Â  Â  Â  Â  Â  Â  Â  [at_c<4>(_val) = _1]
> Â  Â  Â  Â >> Â qi::bool_ Â  Â  Â  Â  Â  Â  Â  Â  [at_c<5>(_val) = _1]
> Â  Â  Â ;
>
>    start = eps            [at_c<4>(_val) = 0]
> Â  Â  Â  Â >> Â *(comment) Â  Â [push_back(at_c<0>(_val), _1)]
> Â  Â  Â  Â >> Â +(selm) Â  Â  Â  [push_back(at_c<1>(_val), _1)]
> Â  Â  Â  Â >> Â ".OUT"
> Â  Â  Â  Â >> Â qi::int_ Â  Â  Â [at_c<4>(_val) = _1]
> Â  Â  Â  Â >> Â ".END";
> Â  Â  Â ;
>
> Â  Â comment.name("comment");
> Â  Â selm.name("selm");
> Â  Â start.name("start");
>
> Â  Â qi::on_error<qi::fail>
> Â  Â  Â (start, err
> Â  Â  Â  Â << val("Syntax error. Expecting ")
> Â  Â  Â  Â << _4
> Â  Â  Â  Â << val(" here: \"")
> Â  Â  Â  Â << construct<std::string>(_3, _2)
> Â  Â  Â  Â << val("\"")
> Â  Â  Â  Â << std::endl
> Â  Â  Â );
> Â }
>
> Â boost::spirit::qi::rule<It, std::string(), space_type> comment;
> Â boost::spirit::qi::rule<It, ::client::selm(), space_type> selm;
> Â boost::spirit::qi::rule<It, ::client::circuit(), space_type> start;
>
> };
>
>
> A more complex example on this idea compiles fine, but invoking it with
> something like:
>
>
> # Comment 1
> R1 1 2 2.5 0
> L32 4 5 0.003 1
> .OUT 3
> .END
>
>
> Returns from phrase_parse with a false value. I don't understand why
> that! I'm sure to be in error (of course, it doesn't work as I want, so
> something is wrong!!) but really since two days ago I look for the error
> whitout find it.
>
> Something to suggest?

Have you turned on the Spirit debugging support?  The documentation
and tests show how to use it and it can show you exactly how it is
working.