Hello,
I've decided to break up my parser into sub-grammars to improve both
the readability and compile time. I'm now trying to specify a skip
parser for one of the sub-grammars, but I don't know how to do it. I'm
familiar with specifying a skip parser in the parse functions, but not
in the grammar itself. Could somebody please provide an example?
Thanks.
#include
#include <string>
#include <iostream>
using namespace boost::spirit;
using namespace boost::spirit::ascii;
template<class Iterator>
struct sub_grammar_skipper: qi::grammar<Iterator>
{
sub_grammar_skipper(): sub_grammar_skipper::base_type(start)
{
start =
(
*((char_ - eol) - lit(':')) >> lit(':') >> *blank >>
*(char_ - eol) >> eol
)
;
}
qi::rule<Iterator> start;
};
template<class Iterator>
struct sub_grammar: qi::grammar<Iterator>
{
sub_grammar(): sub_grammar::base_type(start)
{
string =
(
*(char_ - eol)
)
;
name %=
(
lit("NAME:") >> *blank >> string >> eol
)
;
start =
(
name
)
;
}
qi::rule string;
qi::rule name;
qi::rule<Iterator> start;
};
template<class Iterator>
struct test_grammar: qi::grammar
{
test_grammar(): test_grammar::base_type(start)
{
start =
(
sg >> int_
)
;
}
sub_grammar<Iterator> sg;
qi::rule start;
};
int main()
{
std::string str("NAME: John\nBLAH: blah\n10");
typedef std::string::const_iterator iterator;
iterator first = str.begin();
iterator last = str.end();
test_grammar<iterator> tg;
bool r = parse(first, last, tg);
if(r && first == last)
{
std::cout << "Success!\n";
}
else
{
std::cerr << "Failed to parse at: " << std::string(first, last) <<
std::endl;
return 1;
}
return 0;
}
