ceph/src/boost/libs/spirit/example/x3/calc/calc9/ast.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2014 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_X3_CALC9_AST_HPP)
   8 #define BOOST_SPIRIT_X3_CALC9_AST_HPP
   9
  10 #include <boost/spirit/home/x3/support/ast/variant.hpp>
  11 #include <boost/spirit/home/x3/support/ast/position_tagged.hpp>
  12 #include <boost/fusion/include/io.hpp>
  13 #include <boost/optional.hpp>
  14 #include <list>
  15
  16 namespace client { namespace ast
  17 {
  18     ///////////////////////////////////////////////////////////////////////////
  19     //  The AST
  20     ///////////////////////////////////////////////////////////////////////////
  21     namespace x3 = boost::spirit::x3;
  22
  23     struct nil {};
  24     struct unary;
  25     struct expression;
  26
  27     struct variable : x3::position_tagged
  28     {
  29         variable(std::string const& name = "") : name(name) {}
  30         std::string name;
  31     };
  32
  33     struct operand :
  34         x3::variant<
  35             nil
  36           , unsigned int
  37           , variable
  38           , x3::forward_ast<unary>
  39           , x3::forward_ast<expression>
  40         >
  41     {
  42         using base_type::base_type;
  43         using base_type::operator=;
  44     };
  45
  46     enum optoken
  47     {
  48         op_plus,
  49         op_minus,
  50         op_times,
  51         op_divide,
  52         op_positive,
  53         op_negative,
  54         op_not,
  55         op_equal,
  56         op_not_equal,
  57         op_less,
  58         op_less_equal,
  59         op_greater,
  60         op_greater_equal,
  61         op_and,
  62         op_or
  63     };
  64
  65     struct unary
  66     {
  67         optoken operator_;
  68         operand operand_;
  69     };
  70
  71     struct operation : x3::position_tagged
  72     {
  73         optoken operator_;
  74         operand operand_;
  75     };
  76
  77     struct expression : x3::position_tagged
  78     {
  79         operand first;
  80         std::list<operation> rest;
  81     };
  82
  83     struct assignment : x3::position_tagged
  84     {
  85         variable lhs;
  86         expression rhs;
  87     };
  88
  89     struct variable_declaration
  90     {
  91         assignment assign;
  92     };
  93
  94     struct if_statement;
  95     struct while_statement;
  96     struct statement_list;
  97
  98     struct statement :
  99         x3::variant<
 100             variable_declaration
 101           , assignment
 102           , boost::recursive_wrapper<if_statement>
 103           , boost::recursive_wrapper<while_statement>
 104           , boost::recursive_wrapper<statement_list>
 105         >
 106     {
 107         using base_type::base_type;
 108         using base_type::operator=;
 109     };
 110
 111     struct statement_list : std::list<statement> {};
 112
 113     struct if_statement
 114     {
 115         expression condition;
 116         statement then;
 117         boost::optional<statement> else_;
 118     };
 119
 120     struct while_statement
 121     {
 122         expression condition;
 123         statement body;
 124     };
 125
 126     // print functions for debugging
 127     inline std::ostream& operator<<(std::ostream& out, nil)
 128     {
 129         out << "nil";
 130         return out;
 131     }
 132
 133     inline std::ostream& operator<<(std::ostream& out, variable const& var)
 134     {
 135         out << var.name; return out;
 136     }
 137 }}
 138
 139 #endif