| /*============================================================================= |
| Copyright (c) 2001-2010 Joel de Guzman |
| |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| =============================================================================*/ |
| #if !defined(SPIRIT_SEQUENTIAL_OR_MARCH_12_2007_1130PM) |
| #define SPIRIT_SEQUENTIAL_OR_MARCH_12_2007_1130PM |
| |
| #if defined(_MSC_VER) |
| #pragma once |
| #endif |
| |
| #include <boost/spirit/home/qi/meta_compiler.hpp> |
| #include <boost/spirit/home/qi/detail/pass_function.hpp> |
| #include <boost/spirit/home/qi/detail/attributes.hpp> |
| #include <boost/spirit/home/support/detail/what_function.hpp> |
| #include <boost/spirit/home/support/algorithm/any_if_ns.hpp> |
| #include <boost/fusion/include/as_vector.hpp> |
| #include <boost/fusion/include/for_each.hpp> |
| |
| namespace boost { namespace spirit |
| { |
| /////////////////////////////////////////////////////////////////////////// |
| // Enablers |
| /////////////////////////////////////////////////////////////////////////// |
| template <> |
| struct use_operator<qi::domain, proto::tag::logical_or> // enables || |
| : mpl::true_ {}; |
| |
| template <> |
| struct flatten_tree<qi::domain, proto::tag::logical_or> // flattens || |
| : mpl::true_ {}; |
| }} |
| |
| namespace boost { namespace spirit { namespace qi |
| { |
| template <typename Elements> |
| struct sequential_or : nary_parser<sequential_or<Elements> > |
| { |
| template <typename Context, typename Iterator> |
| struct attribute |
| { |
| // Put all the element attributes in a tuple, |
| // wrapping each element in a boost::optional |
| typedef typename traits::build_attribute_sequence< |
| Elements, Context, traits::build_optional, Iterator>::type |
| all_attributes; |
| |
| // Now, build a fusion vector over the attributes. Note |
| // that build_fusion_vector 1) removes all unused attributes |
| // and 2) may return unused_type if all elements have |
| // unused_type(s). |
| typedef typename |
| traits::build_fusion_vector<all_attributes>::type |
| type; |
| }; |
| |
| sequential_or(Elements const& elements) |
| : elements(elements) {} |
| |
| template <typename Iterator, typename Context |
| , typename Skipper, typename Attribute> |
| bool parse(Iterator& first, Iterator const& last |
| , Context& context, Skipper const& skipper |
| , Attribute& attr_) const |
| { |
| typedef traits::attribute_not_unused<Context, Iterator> predicate; |
| detail::pass_function<Iterator, Context, Skipper> |
| f(first, last, context, skipper); |
| |
| // wrap the attribute in a tuple if it is not a tuple |
| typename traits::wrap_if_not_tuple<Attribute>::type attr(attr_); |
| |
| // return true if *any* of the parsers succeed |
| // (we use the non-short-circuiting version: any_if_ns |
| // to force all elements to be tested) |
| return spirit::any_if_ns(elements, attr, f, predicate()); |
| } |
| |
| template <typename Context> |
| info what(Context& context) const |
| { |
| info result("sequential-or"); |
| fusion::for_each(elements, |
| spirit::detail::what_function<Context>(result, context)); |
| return result; |
| } |
| |
| Elements elements; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Parser generators: make_xxx function (objects) |
| /////////////////////////////////////////////////////////////////////////// |
| template <typename Elements, typename Modifiers> |
| struct make_composite<proto::tag::logical_or, Elements, Modifiers> |
| : make_nary_composite<Elements, sequential_or> |
| {}; |
| }}} |
| |
| namespace boost { namespace spirit { namespace traits |
| { |
| // We specialize this for sequential_or (see support/attributes.hpp). |
| // For sequential_or, we only wrap the attribute in a tuple IFF |
| // it is not already a fusion tuple. |
| template <typename Elements, typename Attribute> |
| struct pass_attribute<qi::sequential_or<Elements>, Attribute> |
| : wrap_if_not_tuple<Attribute> {}; |
| |
| template <typename Elements> |
| struct has_semantic_action<qi::sequential_or<Elements> > |
| : nary_has_semantic_action<Elements> {}; |
| }}} |
| |
| #endif |