ceph/src/boost/boost/spirit/home/qi/operator/sequential_or.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 #ifndef BOOST_SPIRIT_QI_OPERATOR_SEQUENTIAL_OR_HPP
   8 #define BOOST_SPIRIT_QI_OPERATOR_SEQUENTIAL_OR_HPP
   9
  10 #if defined(_MSC_VER)
  11 #pragma once
  12 #endif
  13
  14 #include <boost/spirit/home/qi/meta_compiler.hpp>
  15 #include <boost/spirit/home/qi/detail/pass_function.hpp>
  16 #include <boost/spirit/home/qi/detail/attributes.hpp>
  17 #include <boost/spirit/home/support/detail/what_function.hpp>
  18 #include <boost/spirit/home/support/algorithm/any_if_ns_so.hpp>
  19 #include <boost/spirit/home/support/handles_container.hpp>
  20 #include <boost/fusion/include/as_vector.hpp>
  21 #include <boost/fusion/include/for_each.hpp>
  22 #include <boost/proto/operators.hpp>
  23 #include <boost/proto/tags.hpp>
  24
  25 namespace boost { namespace spirit
  26 {
  27     ///////////////////////////////////////////////////////////////////////////
  28     // Enablers
  29     ///////////////////////////////////////////////////////////////////////////
  30     template <>
  31     struct use_operator<qi::domain, proto::tag::logical_or> // enables ||
  32       : mpl::true_ {};
  33
  34     template <>
  35     struct flatten_tree<qi::domain, proto::tag::logical_or> // flattens ||
  36       : mpl::true_ {};
  37 }}
  38
  39 namespace boost { namespace spirit { namespace qi
  40 {
  41     template <typename Elements>
  42     struct sequential_or : nary_parser<sequential_or<Elements> >
  43     {
  44         template <typename Context, typename Iterator>
  45         struct attribute
  46         {
  47             // Put all the element attributes in a tuple,
  48             // wrapping each element in a boost::optional
  49             typedef typename traits::build_attribute_sequence<
  50                 Elements, Context, traits::sequential_or_attribute_transform
  51               , Iterator, qi::domain
  52             >::type all_attributes;
  53
  54             // Now, build a fusion vector over the attributes. Note
  55             // that build_fusion_vector 1) removes all unused attributes
  56             // and 2) may return unused_type if all elements have
  57             // unused_type(s).
  58             typedef typename
  59                 traits::build_fusion_vector<all_attributes>::type
  60             type;
  61         };
  62
  63         sequential_or(Elements const& elements_)
  64           : elements(elements_) {}
  65
  66         template <typename Iterator, typename Context
  67           , typename Skipper, typename Attribute>
  68         bool parse(Iterator& first, Iterator const& last
  69           , Context& context, Skipper const& skipper
  70           , Attribute& attr_) const
  71         {
  72             typedef traits::attribute_not_unused<Context, Iterator> predicate;
  73             detail::pass_function<Iterator, Context, Skipper>
  74                 f(first, last, context, skipper);
  75
  76             // wrap the attribute in a tuple if it is not a tuple
  77             typename traits::wrap_if_not_tuple<Attribute>::type attr_local(attr_);
  78
  79             // return true if *any* of the parsers succeed
  80             // (we use the non-short-circuiting and strict order version:
  81             // any_if_ns_so to force all the elements to be tested and
  82             // in the defined order: first is first, last is last)
  83             return spirit::any_if_ns_so(elements, attr_local, f, predicate());
  84         }
  85
  86         template <typename Context>
  87         info what(Context& context) const
  88         {
  89             info result("sequential-or");
  90             fusion::for_each(elements,
  91                 spirit::detail::what_function<Context>(result, context));
  92             return result;
  93         }
  94
  95         Elements elements;
  96     };
  97
  98     ///////////////////////////////////////////////////////////////////////////
  99     // Parser generators: make_xxx function (objects)
 100     ///////////////////////////////////////////////////////////////////////////
 101     template <typename Elements, typename Modifiers>
 102     struct make_composite<proto::tag::logical_or, Elements, Modifiers>
 103       : make_nary_composite<Elements, sequential_or>
 104     {};
 105 }}}
 106
 107 namespace boost { namespace spirit { namespace traits
 108 {
 109     ///////////////////////////////////////////////////////////////////////////
 110     // We specialize this for sequential_or (see support/attributes.hpp).
 111     // For sequential_or, we only wrap the attribute in a tuple IFF
 112     // it is not already a fusion tuple.
 113     template <typename Elements, typename Attribute>
 114     struct pass_attribute<qi::sequential_or<Elements>, Attribute>
 115       : wrap_if_not_tuple<Attribute> {};
 116
 117     ///////////////////////////////////////////////////////////////////////////
 118     template <typename Elements>
 119     struct has_semantic_action<qi::sequential_or<Elements> >
 120       : nary_has_semantic_action<Elements> {};
 121
 122     ///////////////////////////////////////////////////////////////////////////
 123     template <typename Elements, typename Attribute, typename Context
 124       , typename Iterator>
 125     struct handles_container<qi::sequential_or<Elements>, Attribute, Context
 126       , Iterator>
 127       : nary_handles_container<Elements, Attribute, Context, Iterator> {};
 128 }}}
 129
 130 #endif