ceph/src/boost/libs/metaparse/example/getting_started/5_2_3.hpp

   1 #ifndef BOOST_METAPARSE_GETTING_STARTED_5_2_3_HPP
   2 #define BOOST_METAPARSE_GETTING_STARTED_5_2_3_HPP
   3
   4 // Automatically generated header file
   5
   6 // Definitions before section 5.2.2
   7 #include "5_2_2.hpp"
   8
   9 // Definitions of section 5.2.2
  10 using exp_parser8 =
  11  build_parser<
  12    sequence<
  13      int_token, /* parse the first <number> */
  14      transform<
  15        repeated<sequence<plus_token, int_token>>, /* parse the "+ <number>" elements */
  16        /* lambda expression summarising the "+ <number>" elements using fold */
  17        boost::mpl::lambda<
  18          /* The folding expression we have just created */
  19          boost::mpl::fold<
  20            boost::mpl::_1, /* the argument of the lambda expression, the result */
  21                            /* of the repeated<...> parser */
  22            boost::mpl::int_<0>,
  23            boost::mpl::quote2<sum_items>
  24          >
  25        >::type
  26      >
  27    >
  28  >;
  29
  30 // query:
  31 //    exp_parser8::apply<BOOST_METAPARSE_STRING("1 + 2 + 3 + 4")>::type
  32
  33 using exp_parser9 =
  34  build_parser<
  35    transform<
  36      /* What we had so far */
  37      sequence<
  38        int_token,
  39        transform<
  40          repeated<sequence<plus_token, int_token>>,
  41          boost::mpl::lambda<
  42            boost::mpl::fold<
  43              boost::mpl::_1,
  44              boost::mpl::int_<0>,
  45              boost::mpl::quote2<sum_items>
  46            >
  47          >::type
  48        >
  49      >,
  50      boost::mpl::quote1<sum_vector> /* summarise the vector of numbers */
  51    >
  52  >;
  53
  54 // query:
  55 //    exp_parser9::apply<BOOST_METAPARSE_STRING("1 + 2 + 3 + 4")>::type
  56
  57 #endif
  58