Styjun

Compiling this simple Spirit grammar results in what seems to be a single error (despite the huge error message), possibly having to do with my skipper or some other template parameter that I have mistakenly used.

I experimented with a variety of attribute definitions for the grammar and the start rule, but it had no effect on the error.

#include <string>
#include "/usr/local/boost/include/boost/spirit/include/qi.hpp"
#include "/usr/local/boost/include/boost/spirit/include/qi_symbols.hpp"

using std::string;

namespace qi = boost::spirit::qi;
namespace ascii = boost::spirit::ascii;

boost::spirit::qi::rule<string::const_iterator>
 skipper_rule = qi::space | '#' >> *(qi::char_ - qi::eol) >> qi::eol;

typedef BOOST_TYPEOF(skipper_rule) skipper_T;

template <typename Iterator, typename Skipper>
 class Grammar1 : boost::spirit::qi::grammar<Iterator, Skipper>
 under) >> *(qi::alnum ;


int main(int argc, char **argv)

 Grammar1<string::const_iterator, skipper_T> g;
 string input("input1.* input2.*");

 g.parseInputFile(input.cbegin(), input.cend());

 

The important parts of the error message seem to be:

/usr/local/boost/include/boost/spirit/home/qi/nonterminal/rule.hpp:304:17:
error: no match for call to ‘(const function_type *REMOVED*)’
 if (f(first, last, context, skipper))
 ^

The comment at line 304 in the above-mentioned Spirit file states that I
may be using an incompatible skipper, but I've tried the much simpler ascii::space_type skipper to no avail.

The rest of the error message:

usr/local/boost/include/boost/function/function_template.hpp:1048:7: note: 
candidate is:
 class function<BOOST_FUNCTION_PARTIAL_SPEC>
 ^
/usr/local/boost/include/boost/function/function_template.hpp:758:17: note:
 boost::function4<R, T1, T2, T3, T4>:: *REMOVED*
 result_type operator()(BOOST_FUNCTION_PARMS) const
 ^

/usr/local/boost/include/boost/function/function_template.hpp:758:17: note:
 no known conversion for argument 4 from ‘const 
boost::spirit::unused_type’ to ‘const boost::spirit::qi::reference<const 
boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*,
 std::basic_string<char> > > >&’

Any idea what I am doing wrong? My compiler is gcc 4.8.5.

You are trying to use rule_nil_T rule which has skipper inside rule_str_T rule which does not. For internal reasons Spirit can only lose skipper when calling a rule. The problem can be easily solved by inlining under, dot, and star at use site.

Note: a rule call in Qi has an overhead. Creating a rule for such a simple parser and then using it inside repeating parser is not a good idea.

Hint: you can utilize raw directive and use literal parsers inside it to get more performant and cleaner to look parser. Consider this: qi::lexeme[qi::raw[(qi::alpha | '_') >> qi::alnum % '.'] >> ".*"].