Ticket #8556: actiontest.cpp

// a test case for combining semantic actions with synthesized attributes in the same rule

#include <iostream>
#include <vector>
#include <string>
#include <iterator>

#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix.hpp>

void action_func(std::string const& a, std::string const& b)
{
   std::cout << "a=" << a << ", b=" << b << std::endl;
}

int main()
{
   typedef std::string::iterator Iterator;

   namespace qi = boost::spirit::qi;
   using boost::spirit::_1;
   using boost::spirit::_2;
   using boost::spirit::_3;
   using boost::spirit::_val;
   using boost::phoenix::bind;
   using boost::phoenix::push_back;

   typedef std::vector<std::string> result_t;
   boost::spirit::qi::rule<Iterator, result_t()> testrule;

   // Goal:
   // Simultaneously store the synthesized attributes (a vector of three size 1 strings)
   // and call the semantic action function on the last two values

   // Actual Result:
   // I can either store the attribute, or call the function, but not both (compile error)

   // things that compile successfully:

   // testrule = qi::string("A") >> qi::string("B") >> qi::string("C") ; // does not call action

   // does not store the synthesized attribute:
   // testrule = (qi::string("A") >> qi::string("B") >> qi::string("C"))[bind(action_func, _1, _2)] ;

   // my desired syntax (does not compile):
   testrule %= (qi::string("A") >> qi::string("B") >> qi::string("C"))[bind(action_func, _1, _2)] ;


   // this is a workaround but is not as concise
/*
   testrule = (qi::string("A") >> qi::string("B") >> qi::string("C"))[bind(action_func, _1, _2),
                                                                      push_back(_val, _1),
                                                                      push_back(_val, _2),
                                                                      push_back(_val, _3)];
*/

   std::string testdata("ABC");
   result_t result;
   Iterator beg = testdata.begin();
   if (!qi::parse(beg, testdata.end(), testrule, result))
   {
      std::cerr << "parse failed" << std::endl;
      return 1;
   }
   if (beg != testdata.end())
   {
      std::cerr << "not all input consumed! Remaining: ";
      std::copy(beg, testdata.end(), std::ostream_iterator<char>(std::cerr, ""));
      std::cerr << std::endl;
      return 2;
   }

   std::cout << "parsed vector result:" << std::endl;
   std::copy(result.begin(), result.end(), std::ostream_iterator<std::string>(std::cout, "\n"));

   return 0;
}