boost/spirit/home/karma/operator/list.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_LIST_HPP #define BOOST_SPIRIT_KARMA_OPERATOR_LIST_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/output_iterator.hpp> #include <boost/spirit/home/karma/detail/indirect_iterator.hpp> #include <boost/spirit/home/karma/detail/get_stricttag.hpp> #include <boost/spirit/home/karma/detail/pass_container.hpp> #include <boost/spirit/home/karma/detail/fail_function.hpp> #include <boost/spirit/home/support/info.hpp> #include <boost/spirit/home/support/unused.hpp> #include <boost/spirit/home/support/container.hpp> #include <boost/spirit/home/support/handles_container.hpp> #include <boost/spirit/home/karma/detail/attributes.hpp> #include <boost/proto/operators.hpp> #include <boost/proto/tags.hpp> namespace boost { namespace spirit { /////////////////////////////////////////////////////////////////////////// // Enablers /////////////////////////////////////////////////////////////////////////// template <> struct use_operator<karma::domain, proto::tag::modulus> // enables g % d : mpl::true_ {}; }} /////////////////////////////////////////////////////////////////////////////// namespace boost { namespace spirit { namespace karma { template <typename Left, typename Right, typename Strict, typename Derived> struct base_list : binary_generator<Derived> { private: // iterate over the given container until its exhausted or the embedded // (left) generator succeeds template <typename F, typename Attribute> bool generate_left(F f, Attribute const&, mpl::false_) const { // Failing subject generators are just skipped. This allows to // selectively generate items in the provided attribute. while (!f.is_at_end()) { bool r = !f(left); if (r) return true; if (!f.is_at_end()) f.next(); } return false; } template <typename F, typename Attribute> bool generate_left(F f, Attribute const&, mpl::true_) const { return !f(left); } // There is no way to distinguish a failed generator from a // generator to be skipped. We assume the user takes responsibility // for ending the loop if no attribute is specified. template <typename F> bool generate_left(F f, unused_type, mpl::false_) const { return !f(left); } public: typedef Left left_type; typedef Right right_type; typedef mpl::int_< left_type::properties::value | right_type::properties::value | generator_properties::buffering | generator_properties::counting > properties; // Build a std::vector from the LHS's attribute. Note // that build_std_vector may return unused_type if the // subject's attribute is an unused_type. template <typename Context, typename Iterator> struct attribute : traits::build_std_vector< typename traits::attribute_of<Left, Context, Iterator>::type> {}; base_list(Left const& left, Right const& right) : left(left), right(right) {} template < typename OutputIterator, typename Context, typename Delimiter , typename Attribute> bool generate(OutputIterator& sink, Context& ctx , Delimiter const& d, Attribute const& attr) const { 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::false_> pass_container; iterator_type it = traits::begin(attr); iterator_type end = traits::end(attr); pass_container pass(fail_function(sink, ctx, d), indirect_iterator_type(it), indirect_iterator_type(end)); if (generate_left(pass, attr, Strict())) { while (!pass.is_at_end()) { // wrap the given output iterator as generate_left might fail detail::enable_buffering<OutputIterator> buffering(sink); { detail::disable_counting<OutputIterator> nocounting(sink); if (!right.generate(sink, ctx, d, unused)) return false; // shouldn't happen if (!generate_left(pass, attr, Strict())) break; // return true as one item succeeded } buffering.buffer_copy(); } return detail::sink_is_good(sink); } return false; } template <typename Context> info what(Context& context) const { return info("list", std::make_pair(left.what(context), right.what(context))); } Left left; Right right; }; template <typename Left, typename Right> struct list : base_list<Left, Right, mpl::false_, list<Left, Right> > { typedef base_list<Left, Right, mpl::false_, list> base_list_; list(Left const& left, Right const& right) : base_list_(left, right) {} }; template <typename Left, typename Right> struct strict_list : base_list<Left, Right, mpl::true_, strict_list<Left, Right> > { typedef base_list<Left, Right, mpl::true_, strict_list> base_list_; strict_list (Left const& left, Right const& right) : base_list_(left, right) {} }; /////////////////////////////////////////////////////////////////////////// // Generator generators: make_xxx function (objects) /////////////////////////////////////////////////////////////////////////// namespace detail { template <typename Subject, bool strict_mode = false> struct make_list : make_binary_composite<Subject, list> {}; template <typename Subject> struct make_list<Subject, true> : make_binary_composite<Subject, strict_list> {}; } template <typename Subject, typename Modifiers> struct make_composite<proto::tag::modulus, Subject, Modifiers> : detail::make_list<Subject, detail::get_stricttag<Modifiers>::value> {}; }}} namespace boost { namespace spirit { namespace traits { /////////////////////////////////////////////////////////////////////////// template <typename Left, typename Right> struct has_semantic_action<karma::list<Left, Right> > : binary_has_semantic_action<Left, Right> {}; template <typename Left, typename Right> struct has_semantic_action<karma::strict_list<Left, Right> > : binary_has_semantic_action<Left, Right> {}; /////////////////////////////////////////////////////////////////////////// template <typename Left, typename Right, typename Attribute , typename Context, typename Iterator> struct handles_container<karma::list<Left, Right>, Attribute , Context, Iterator> : mpl::true_ {}; template <typename Left, typename Right, typename Attribute , typename Context, typename Iterator> struct handles_container<karma::strict_list<Left, Right>, Attribute , Context, Iterator> : mpl::true_ {}; }}} #endif