1 /*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
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(SPIRIT_SEQUENTIAL_OR_MARCH_12_2007_1130PM)
8 #define SPIRIT_SEQUENTIAL_OR_MARCH_12_2007_1130PM
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.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>
23 namespace boost { namespace spirit
25 ///////////////////////////////////////////////////////////////////////////
27 ///////////////////////////////////////////////////////////////////////////
29 struct use_operator<qi::domain, proto::tag::logical_or> // enables ||
33 struct flatten_tree<qi::domain, proto::tag::logical_or> // flattens ||
37 namespace boost { namespace spirit { namespace qi
39 template <typename Elements>
40 struct sequential_or : nary_parser<sequential_or<Elements> >
42 template <typename Context, typename Iterator>
45 // Put all the element attributes in a tuple,
46 // wrapping each element in a boost::optional
47 typedef typename traits::build_attribute_sequence<
48 Elements, Context, traits::sequential_or_attribute_transform
49 , Iterator, qi::domain
50 >::type all_attributes;
52 // Now, build a fusion vector over the attributes. Note
53 // that build_fusion_vector 1) removes all unused attributes
54 // and 2) may return unused_type if all elements have
57 traits::build_fusion_vector<all_attributes>::type
61 sequential_or(Elements const& elements_)
62 : elements(elements_) {}
64 template <typename Iterator, typename Context
65 , typename Skipper, typename Attribute>
66 bool parse(Iterator& first, Iterator const& last
67 , Context& context, Skipper const& skipper
68 , Attribute& attr_) const
70 typedef traits::attribute_not_unused<Context, Iterator> predicate;
71 detail::pass_function<Iterator, Context, Skipper>
72 f(first, last, context, skipper);
74 // wrap the attribute in a tuple if it is not a tuple
75 typename traits::wrap_if_not_tuple<Attribute>::type attr_local(attr_);
77 // return true if *any* of the parsers succeed
78 // (we use the non-short-circuiting version: any_if_ns
79 // to force all elements to be tested)
80 return spirit::any_if_ns(elements, attr_local, f, predicate());
83 template <typename Context>
84 info what(Context& context) const
86 info result("sequential-or");
87 fusion::for_each(elements,
88 spirit::detail::what_function<Context>(result, context));
95 ///////////////////////////////////////////////////////////////////////////
96 // Parser generators: make_xxx function (objects)
97 ///////////////////////////////////////////////////////////////////////////
98 template <typename Elements, typename Modifiers>
99 struct make_composite<proto::tag::logical_or, Elements, Modifiers>
100 : make_nary_composite<Elements, sequential_or>
104 namespace boost { namespace spirit { namespace traits
106 ///////////////////////////////////////////////////////////////////////////
107 // We specialize this for sequential_or (see support/attributes.hpp).
108 // For sequential_or, we only wrap the attribute in a tuple IFF
109 // it is not already a fusion tuple.
110 template <typename Elements, typename Attribute>
111 struct pass_attribute<qi::sequential_or<Elements>, Attribute>
112 : wrap_if_not_tuple<Attribute> {};
114 ///////////////////////////////////////////////////////////////////////////
115 template <typename Elements>
116 struct has_semantic_action<qi::sequential_or<Elements> >
117 : nary_has_semantic_action<Elements> {};
119 ///////////////////////////////////////////////////////////////////////////
120 template <typename Elements, typename Attribute, typename Context
122 struct handles_container<qi::sequential_or<Elements>, Attribute, Context
124 : nary_handles_container<Elements, Attribute, Context, Iterator> {};