Re: Design/structure X3 parser more like Qi parser

On 12/13/2016 11:56 AM, Seth wrote:
[snip]
> The resultant X3 neatly expresses why I don't think modularity of X3 is
> any problem. It employs only one or two tricks, which **exploit** the
> fact that X3 is actually /just c++ code/ and behaves as such:
>
>     namespace csv {
>         template <typename Sep>
>         auto make_csv_parser(Sep fieldSep) {
>             using namespace boost::spirit::x3;
>
>             using R = rule<struct _, CsvString>;
>
>             auto unescaped = R{"raw"}    = *(~char_("\"\r\n") - fieldSep);
>             auto escaped   = R{"quoted"} = *(~char_('"') | '"' >>
>     char_('"'));
>             auto lineBreak = eol;
>
>             auto field = R{"field"} =
>                 (*lit(' ') >> ('"' > escaped > '"') >> *lit(' '))
>                 | unescaped; // the order is important because unescaped
>     can consume zero characters
>
>             auto record = rule<struct _, CsvRecordInformation>{ "record" } =
>                 field % fieldSep;
>
>             auto file   = rule<struct _, CsvFileInformation>{ "file" } =
>                 ((!eoi > record) % lineBreak) > -lineBreak > eoi;
>
>             return file;
>         };
>     }
>
[snip]
This doesn't use BOOST_SPIRIT_DEFINE, and I don't think it can
because that would generate one or more parse_rule's template functions
within the make_csv_parser function.  Is that right?
If so, then wouldn't that make this method slower to compile than if
BOOST_SPIRIT_DEFINE could be used?

-regards,
Larry




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