1 /*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
3 Copyright (c) 2001-2011 Hartmut Kaiser
5 Distributed under the Boost Software License, Version 1.0. (See accompanying
6 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7 =============================================================================*/
8 #if !defined(SPIRIT_SEQUENCE_BASE_APRIL_22_2006_0811AM)
9 #define SPIRIT_SEQUENCE_BASE_APRIL_22_2006_0811AM
15 #include <boost/spirit/home/qi/domain.hpp>
16 #include <boost/spirit/home/qi/detail/pass_container.hpp>
17 #include <boost/spirit/home/qi/detail/attributes.hpp>
18 #include <boost/spirit/home/support/algorithm/any_if.hpp>
19 #include <boost/spirit/home/support/detail/what_function.hpp>
20 #include <boost/spirit/home/support/unused.hpp>
21 #include <boost/spirit/home/support/info.hpp>
22 #include <boost/spirit/home/support/sequence_base_id.hpp>
23 #include <boost/spirit/home/support/has_semantic_action.hpp>
24 #include <boost/spirit/home/qi/parser.hpp>
25 #include <boost/fusion/include/as_vector.hpp>
26 #include <boost/fusion/include/vector.hpp>
27 #include <boost/fusion/include/for_each.hpp>
28 #include <boost/mpl/identity.hpp>
30 namespace boost { namespace spirit { namespace qi
32 template <typename Derived, typename Elements>
33 struct sequence_base // this class is shared by sequence and expect
34 : nary_parser<Derived>
36 typedef Elements elements_type;
37 struct sequence_base_id;
39 template <typename Context, typename Iterator>
42 // Put all the element attributes in a tuple
43 typedef typename traits::build_attribute_sequence<
44 Elements, Context, traits::sequence_attribute_transform
45 , Iterator, qi::domain
46 >::type all_attributes;
48 // Now, build a fusion vector over the attributes. Note
49 // that build_fusion_vector 1) removes all unused attributes
50 // and 2) may return unused_type if all elements have
53 traits::build_fusion_vector<all_attributes>::type
56 // Finally, strip single element vectors into its
57 // naked form: vector1<T> --> T
59 traits::strip_single_element_vector<type_>::type
63 sequence_base(Elements const& elements_)
64 : elements(elements_) {}
66 // standard case. Attribute is a fusion tuple
67 template <typename Iterator, typename Context
68 , typename Skipper, typename Attribute>
69 bool parse_impl(Iterator& first, Iterator const& last
70 , Context& context, Skipper const& skipper
71 , Attribute& attr_, mpl::false_) const
73 Iterator iter = first;
74 typedef traits::attribute_not_unused<Context, Iterator> predicate;
76 // wrap the attribute in a tuple if it is not a tuple or if the
77 // attribute of this sequence is a single element tuple
78 typedef typename attribute<Context, Iterator>::type_ attr_type_;
79 typename traits::wrap_if_not_tuple<Attribute
81 traits::one_element_sequence<attr_type_>
82 , mpl::not_<traits::one_element_sequence<Attribute> >
84 >::type attr_local(attr_);
86 // return false if *any* of the parsers fail
87 if (spirit::any_if(elements, attr_local
88 , Derived::fail_function(iter, last, context, skipper), predicate()))
94 // Special case when Attribute is an stl container
95 template <typename Iterator, typename Context
96 , typename Skipper, typename Attribute>
97 bool parse_impl(Iterator& first, Iterator const& last
98 , Context& context, Skipper const& skipper
99 , Attribute& attr_, mpl::true_) const
101 // ensure the attribute is actually a container type
102 traits::make_container(attr_);
104 Iterator iter = first;
105 // return false if *any* of the parsers fail
106 if (fusion::any(elements
107 , detail::make_sequence_pass_container(
108 Derived::fail_function(iter, last, context, skipper), attr_))
115 // main parse function. Dispatches to parse_impl depending
116 // on the Attribute type.
117 template <typename Iterator, typename Context
118 , typename Skipper, typename Attribute>
119 bool parse(Iterator& first, Iterator const& last
120 , Context& context, Skipper const& skipper
121 , Attribute& attr_) const
123 return parse_impl(first, last, context, skipper, attr_
124 , traits::is_container<Attribute>());
127 template <typename Context>
128 info what(Context& context) const
130 info result(this->derived().id());
131 fusion::for_each(elements,
132 spirit::detail::what_function<Context>(result, context));