cpp_expression_grammar.hpp

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    template <typename ScannerT>
    struct definition
    {
        typedef closures::cpp_expr_closure closure_type;
        typedef boost::spirit::classic::rule<ScannerT, closure_type::context_t> rule_t;
        typedef boost::spirit::classic::rule<ScannerT> simple_rule_t;

        simple_rule_t pp_expression;
        
        rule_t const_exp;
        rule_t logical_or_exp, logical_and_exp;
        rule_t inclusive_or_exp, exclusive_or_exp, and_exp;
        rule_t cmp_equality, cmp_relational;
        rule_t shift_exp;
        rule_t add_exp, multiply_exp;
        rule_t unary_exp, primary_exp, constant;

        rule_t const_exp_nocalc;
        rule_t logical_or_exp_nocalc, logical_and_exp_nocalc;
        rule_t inclusive_or_exp_nocalc, exclusive_or_exp_nocalc, and_exp_nocalc;
        rule_t cmp_equality_nocalc, cmp_relational_nocalc;
        rule_t shift_exp_nocalc;
        rule_t add_exp_nocalc, multiply_exp_nocalc;
        rule_t unary_exp_nocalc, primary_exp_nocalc, constant_nocalc;

        boost::spirit::classic::subrule<0, closure_type::context_t> const_exp_subrule;

        definition(expression_grammar const &self)
        {
            using namespace boost::spirit::classic;
            using namespace phoenix;
            using namespace boost::wave;
            using boost::wave::util::pattern_p;
            
            pp_expression
                =   const_exp[self.val = arg1]
                ;
                
            const_exp
                =   logical_or_exp[const_exp.val = arg1]
                    >> !(const_exp_subrule =
                            ch_p(T_QUESTION_MARK)
                            >>  const_exp
                                [
                                    const_exp_subrule.val = arg1
                                ] 
                            >>  ch_p(T_COLON)
                            >>  const_exp
                                [
                                    const_exp_subrule.val = 
                                        impl::questionmark(const_exp.val, 
                                            const_exp_subrule.val, arg1)
                                ]
                        )[const_exp.val = arg1]
                ;

            logical_or_exp 
                =   logical_and_exp[logical_or_exp.val = arg1]
                    >> *(   if_p(impl::as_bool(logical_or_exp.val))
                            [
                                // if one of the || operators is true, no more
                                // evaluation is required
                                pattern_p(T_OROR, MainTokenMask)
                                >>  logical_and_exp_nocalc
                                    [
                                        logical_or_exp.val = 
                                            impl::to_bool(logical_or_exp.val)
                                    ]
                            ]
                            .else_p
                            [
                                pattern_p(T_OROR, MainTokenMask)
                                >>  logical_and_exp
                                    [
                                        logical_or_exp.val = 
                                            impl::binary_or(logical_or_exp.val, arg1)
                                    ]
                            ]
                        )
                ;

            logical_and_exp
                =   inclusive_or_exp[logical_and_exp.val = arg1]
                    >> *(   if_p(impl::as_bool(logical_and_exp.val))
                            [
                                pattern_p(T_ANDAND, MainTokenMask)
                                >>  inclusive_or_exp
                                    [
                                        logical_and_exp.val = 
                                            impl::binary_and(logical_and_exp.val, arg1)
                                    ]
                            ]
                            .else_p
                            [
                                // if one of the && operators is false, no more
                                // evaluation is required
                                pattern_p(T_ANDAND, MainTokenMask)
                                >>  inclusive_or_exp_nocalc
                                    [
                                        logical_and_exp.val =
                                            impl::to_bool(logical_and_exp.val)
                                    ]
                            ]
                        )
                ;

            inclusive_or_exp
                =   exclusive_or_exp[inclusive_or_exp.val = arg1]
                    >> *(   pattern_p(T_OR, MainTokenMask)
                            >>  exclusive_or_exp
                                [
                                    inclusive_or_exp.val = 
                                        impl::binary_bitor(inclusive_or_exp.val, arg1)
                                ]
                        )
                ;

            exclusive_or_exp
                =   and_exp[exclusive_or_exp.val = arg1]
                    >> *(   pattern_p(T_XOR, MainTokenMask)
                            >>  and_exp
                                [
                                    exclusive_or_exp.val = 
                                        impl::binary_bitxor(exclusive_or_exp.val, arg1)
                                ]
                        )
                ;

            and_exp
                =   cmp_equality[and_exp.val = arg1]
                    >> *(   pattern_p(T_AND, MainTokenMask)
                            >>  cmp_equality
                                [
                                    and_exp.val = 
                                        impl::binary_bitand(and_exp.val, arg1)
                                ]
                        )
                ;

            cmp_equality
                =   cmp_relational[cmp_equality.val = arg1]
                    >> *(   ch_p(T_EQUAL)
                            >>  cmp_relational
                                [
                                    cmp_equality.val = 
                                        impl::binary_eq(cmp_equality.val, arg1)
                                ]
                        |   pattern_p(T_NOTEQUAL, MainTokenMask)
                            >>  cmp_relational
                                [
                                    cmp_equality.val = 
                                        impl::binary_ne(cmp_equality.val, arg1)
                                ]
                        )
                ;

            cmp_relational
                =   shift_exp[cmp_relational.val = arg1]
                    >> *(   ch_p(T_LESSEQUAL)
                            >>  shift_exp
                                [
                                    cmp_relational.val = 
                                        impl::binary_lesseq(cmp_relational.val, arg1)
                                ]
                        |   ch_p(T_GREATEREQUAL)
                            >>  shift_exp
                                [
                                    cmp_relational.val = 
                                        impl::binary_greateq(cmp_relational.val, arg1)
                                ]
                        |   ch_p(T_LESS)
                            >>  shift_exp
                                [
                                    cmp_relational.val = 
                                        impl::binary_less(cmp_relational.val, arg1)
                                ]
                        |   ch_p(T_GREATER)
                            >>  shift_exp
                                [
                                    cmp_relational.val = 
                                        impl::binary_greater(cmp_relational.val, arg1)
                                ]
                        )
                ;

            shift_exp
                =   add_exp[shift_exp.val = arg1]
                    >> *(   ch_p(T_SHIFTLEFT)
                            >>  add_exp
                                [
                                    shift_exp.val <<= arg1
                                ]
                        |   ch_p(T_SHIFTRIGHT)
                            >>  add_exp
                                [
                                    shift_exp.val >>= arg1
                                ]
                        )
                ;

            add_exp
                =   multiply_exp[add_exp.val = arg1]
                    >> *(   ch_p(T_PLUS)
                            >>  multiply_exp
                                [
                                    add_exp.val += arg1
                                ]
                        |   ch_p(T_MINUS)
                            >>  multiply_exp
                                [
                                    add_exp.val -= arg1
                                ]
                        )
                ;

            multiply_exp
                =   unary_exp[multiply_exp.val = arg1]
                    >> *(   ch_p(T_STAR)
                            >>  unary_exp
                                [
                                    multiply_exp.val *= arg1
                                ]
                        |   ch_p(T_DIVIDE)
                            >>  unary_exp
                                [
                                    multiply_exp.val /= arg1
                                ]
                        |   ch_p(T_PERCENT)
                            >>  unary_exp
                                [
                                    multiply_exp.val %= arg1
                                ]
                        )
                ;

            unary_exp
                =   primary_exp[unary_exp.val = arg1]
                |   ch_p(T_PLUS) >> unary_exp
                    [
                        unary_exp.val = arg1
                    ]
                |   ch_p(T_MINUS) >> unary_exp
                    [
                        unary_exp.val = -arg1
                    ]
                |   pattern_p(T_COMPL, MainTokenMask) >> unary_exp
                    [
                        unary_exp.val = ~arg1
                    ]
                |   pattern_p(T_NOT, MainTokenMask) >> unary_exp
                    [
                        unary_exp.val = impl::unary_neg(arg1)
                    ]
                ;

            primary_exp
                =   constant[primary_exp.val = arg1]
                |   ch_p(T_LEFTPAREN) 
                    >> const_exp[primary_exp.val = arg1]
                    >> ch_p(T_RIGHTPAREN)
                ;

            constant
                =   ch_p(T_PP_NUMBER) 
                    [
                        constant.val = impl::as_intlit(arg1)
                    ]
                |   ch_p(T_INTLIT) 
                    [
                        constant.val = impl::as_intlit(arg1)
                    ]
                |   ch_p(T_CHARLIT) 
                    [
                        constant.val = impl::as_chlit(arg1)
                    ]
                ;
              
            //  here follows the same grammar, but without any embedded 
            //  calculations
            const_exp_nocalc
                =   logical_or_exp_nocalc
                    >> !(   ch_p(T_QUESTION_MARK)
                            >>  const_exp_nocalc
                            >>  ch_p(T_COLON)