ceph/src/boost/libs/spirit/example/qi/compiler_tutorial/calc8/annotation.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 Joel de Guzman
   3
   4     Distributed under the Boost Software License, Version 1.0. (See accompanying
   5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 =============================================================================*/
   7 #if !defined(BOOST_SPIRIT_CALC8_ANNOTATION_HPP)
   8 #define BOOST_SPIRIT_CALC8_ANNOTATION_HPP
   9
  10 #include <map>
  11 #include <boost/variant/apply_visitor.hpp>
  12 #include <boost/type_traits/is_base_of.hpp>
  13 #include <boost/mpl/bool.hpp>
  14 #include "ast.hpp"
  15
  16 namespace client
  17 {
  18     ///////////////////////////////////////////////////////////////////////////////
  19     //  The annotation handler links the AST to a map of iterator positions
  20     //  for the purpose of subsequent semantic error handling when the
  21     //  program is being compiled.
  22     ///////////////////////////////////////////////////////////////////////////////
  23     template <typename Iterator>
  24     struct annotation
  25     {
  26         template <typename, typename>
  27         struct result { typedef void type; };
  28
  29         std::vector<Iterator>& iters;
  30         annotation(std::vector<Iterator>& iters)
  31           : iters(iters) {}
  32
  33         struct set_id
  34         {
  35             typedef void result_type;
  36
  37             int id;
  38             set_id(int id) : id(id) {}
  39
  40             template <typename T>
  41             void operator()(T& x) const
  42             {
  43                 this->dispatch(x, boost::is_base_of<ast::tagged, T>());
  44             }
  45
  46             // This will catch all nodes except those inheriting from ast::tagged
  47             template <typename T>
  48             void dispatch(T& x, boost::mpl::false_) const
  49             {
  50                 // (no-op) no need for tags
  51             }
  52
  53             // This will catch all nodes inheriting from ast::tagged
  54             template <typename T>
  55             void dispatch(T& x, boost::mpl::true_) const
  56             {
  57                 x.id = id;
  58             }
  59         };
  60
  61         void operator()(ast::operand& ast, Iterator pos) const
  62         {
  63             int id = iters.size();
  64             iters.push_back(pos);
  65             boost::apply_visitor(set_id(id), ast);
  66         }
  67
  68         void operator()(ast::assignment& ast, Iterator pos) const
  69         {
  70             int id = iters.size();
  71             iters.push_back(pos);
  72             ast.lhs.id = id;
  73         }
  74     };
  75 }
  76
  77 #endif
  78