boost/spirit/home/karma/operator/sequence.hpp
// Copyright (c) 2001-2011 Hartmut Kaiser // Copyright (c) 2001-2011 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) #ifndef BOOST_SPIRIT_KARMA_OPERATOR_SEQUENCE_HPP #define BOOST_SPIRIT_KARMA_OPERATOR_SEQUENCE_HPP #if defined(_MSC_VER) #pragma once #endif #include <boost/spirit/home/karma/domain.hpp> #include <boost/spirit/home/karma/generator.hpp> #include <boost/spirit/home/karma/meta_compiler.hpp> #include <boost/spirit/home/karma/detail/fail_function.hpp> #include <boost/spirit/home/karma/detail/pass_container.hpp> #include <boost/spirit/home/karma/detail/get_stricttag.hpp> #include <boost/spirit/home/support/info.hpp> #include <boost/spirit/home/support/detail/what_function.hpp> #include <boost/spirit/home/karma/detail/attributes.hpp> #include <boost/spirit/home/karma/detail/indirect_iterator.hpp> #include <boost/spirit/home/support/algorithm/any_if.hpp> #include <boost/spirit/home/support/unused.hpp> #include <boost/spirit/home/support/sequence_base_id.hpp> #include <boost/spirit/home/support/has_semantic_action.hpp> #include <boost/spirit/home/support/handles_container.hpp> #include <boost/spirit/home/support/attributes.hpp> #include <boost/fusion/include/vector.hpp> #include <boost/fusion/include/as_vector.hpp> #include <boost/fusion/include/for_each.hpp> #include <boost/type_traits/is_same.hpp> #include <boost/mpl/bitor.hpp> #include <boost/mpl/int.hpp> #include <boost/mpl/and.hpp> #include <boost/mpl/not.hpp> #include <boost/fusion/include/transform.hpp> #include <boost/mpl/accumulate.hpp> #include <boost/proto/operators.hpp> #include <boost/proto/tags.hpp> #include <boost/config.hpp> /////////////////////////////////////////////////////////////////////////////// namespace boost { namespace spirit { /////////////////////////////////////////////////////////////////////////// // Enablers /////////////////////////////////////////////////////////////////////////// template <> struct use_operator<karma::domain, proto::tag::shift_left> // enables << : mpl::true_ {}; template <> struct flatten_tree<karma::domain, proto::tag::shift_left> // flattens << : mpl::true_ {}; }} /////////////////////////////////////////////////////////////////////////////// namespace boost { namespace spirit { namespace traits { // specialization for sequences template <typename Elements> struct sequence_properties { struct element_properties { template <typename T> struct result; template <typename F, typename Element> struct result<F(Element)> { typedef properties_of<Element> type; }; // never called, but needed for decltype-based result_of (C++0x) #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES template <typename Element> typename result<element_properties(Element)>::type operator()(Element&&) const; #endif }; typedef typename mpl::accumulate< typename fusion::result_of::transform< Elements, element_properties>::type , mpl::int_<karma::generator_properties::no_properties> , mpl::bitor_<mpl::_2, mpl::_1> >::type type; }; }}} /////////////////////////////////////////////////////////////////////////////// namespace boost { namespace spirit { namespace karma { template <typename Elements, typename Strict, typename Derived> struct base_sequence : nary_generator<Derived> { typedef typename traits::sequence_properties<Elements>::type properties; base_sequence(Elements const& elements) : elements(elements) {} typedef Elements elements_type; struct sequence_base_id; template <typename Context, typename Iterator = unused_type> struct attribute { // Put all the element attributes in a tuple typedef typename traits::build_attribute_sequence< Elements, Context, traits::sequence_attribute_transform , Iterator, karma::domain >::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_; // Finally, strip single element vectors into its // naked form: vector1<T> --> T typedef typename traits::strip_single_element_vector<type_>::type type; }; // standard case. Attribute is a fusion tuple template < typename OutputIterator, typename Context, typename Delimiter , typename Attribute, typename Pred1, typename Pred2> bool generate_impl(OutputIterator& sink, Context& ctx , Delimiter const& d, Attribute& attr_, Pred1, Pred2) const { typedef detail::fail_function< OutputIterator, Context, Delimiter> fail_function; typedef traits::attribute_not_unused<Context> predicate; // wrap the attribute in a tuple if it is not a tuple or if the // attribute of this sequence is a single element tuple typedef typename attribute<Context>::type_ attr_type_; typename traits::wrap_if_not_tuple<Attribute , typename mpl::and_< traits::one_element_sequence<attr_type_> , mpl::not_<traits::one_element_sequence<Attribute> > >::type >::type attr(attr_); // return false if *any* of the generators fail bool r = spirit::any_if(elements, attr , fail_function(sink, ctx, d), predicate()); typedef typename traits::attribute_size<Attribute>::type size_type; // fail generating if sequences have not the same (logical) length return !r && (!Strict::value || // This ignores container element count (which is not good), // but allows valid attributes to succeed. This will lead to // false positives (failing generators, even if they shouldn't) // if the embedded component is restricting the number of // container elements it consumes (i.e. repeat). This solution // is not optimal but much better than letting _all_ repetitive // components fail. Pred1::value || size_type(traits::sequence_size<attr_type_>::value) == traits::size(attr_)); } // Special case when Attribute is an stl container and the sequence's // attribute is not a one element sequence template < typename OutputIterator, typename Context, typename Delimiter , typename Attribute> bool generate_impl(OutputIterator& sink, Context& ctx , Delimiter const& d, Attribute const& attr_ , mpl::true_, mpl::false_) const { // return false if *any* of the generators fail typedef detail::fail_function< OutputIterator, Context, Delimiter> fail_function; typedef typename traits::container_iterator< typename add_const<Attribute>::type >::type iterator_type; typedef typename traits::make_indirect_iterator<iterator_type>::type indirect_iterator_type; typedef detail::pass_container< fail_function, Attribute, indirect_iterator_type, mpl::true_> pass_container; iterator_type begin = traits::begin(attr_); iterator_type end = traits::end(attr_); pass_container pass(fail_function(sink, ctx, d), indirect_iterator_type(begin), indirect_iterator_type(end)); bool r = fusion::any(elements, pass); // fail generating if sequences have not the same (logical) length return !r && (!Strict::value || begin == end); } // main generate function. Dispatches to generate_impl depending // on the Attribute type. template < typename OutputIterator, typename Context, typename Delimiter , typename Attribute> bool generate(OutputIterator& sink, Context& ctx, Delimiter const& d , Attribute const& attr) const { typedef typename traits::is_container<Attribute>::type is_container; typedef typename attribute<Context>::type_ attr_type_; typedef typename traits::one_element_sequence<attr_type_>::type is_one_element_sequence; return generate_impl(sink, ctx, d, attr, is_container() , is_one_element_sequence()); } template <typename Context> info what(Context& context) const { info result("sequence"); fusion::for_each(elements, spirit::detail::what_function<Context>(result, context)); return result; } Elements elements; }; template <typename Elements> struct sequence : base_sequence<Elements, mpl::false_, sequence<Elements> > { typedef base_sequence<Elements, mpl::false_, sequence> base_sequence_; sequence(Elements const& subject) : base_sequence_(subject) {} }; template <typename Elements> struct strict_sequence : base_sequence<Elements, mpl::true_, strict_sequence<Elements> > { typedef base_sequence<Elements, mpl::true_, strict_sequence> base_sequence_; strict_sequence(Elements const& subject) : base_sequence_(subject) {} }; /////////////////////////////////////////////////////////////////////////// // Generator generators: make_xxx function (objects) /////////////////////////////////////////////////////////////////////////// namespace detail { template <typename Elements, bool strict_mode = false> struct make_sequence : make_nary_composite<Elements, sequence> {}; template <typename Elements> struct make_sequence<Elements, true> : make_nary_composite<Elements, strict_sequence> {}; } template <typename Elements, typename Modifiers> struct make_composite<proto::tag::shift_left, Elements, Modifiers> : detail::make_sequence<Elements, detail::get_stricttag<Modifiers>::value> {}; /////////////////////////////////////////////////////////////////////////// // Helper template allowing to get the required container type for a rule // attribute, which is part of a sequence. template <typename Iterator> struct make_sequence_iterator_range { typedef iterator_range<detail::indirect_iterator<Iterator> > type; }; }}} namespace boost { namespace spirit { namespace traits { /////////////////////////////////////////////////////////////////////////// template <typename Elements> struct has_semantic_action<karma::sequence<Elements> > : nary_has_semantic_action<Elements> {}; template <typename Elements> struct has_semantic_action<karma::strict_sequence<Elements> > : nary_has_semantic_action<Elements> {}; /////////////////////////////////////////////////////////////////////////// template <typename Elements, typename Attribute, typename Context , typename Iterator> struct handles_container<karma::sequence<Elements>, Attribute, Context , Iterator> : mpl::true_ {}; template <typename Elements, typename Attribute, typename Context , typename Iterator> struct handles_container<karma::strict_sequence<Elements>, Attribute , Context, Iterator> : mpl::true_ {}; }}} #endif