comparison DEPENDENCIES/generic/include/boost/spirit/home/classic/meta/traverse.hpp @ 16:2665513ce2d3

Add boost headers

+/*=============================================================================
+    Copyright (c) 2002-2003 Joel de Guzman
+    Copyright (c) 2002-2003 Hartmut Kaiser
+    http://spirit.sourceforge.net/
+
+  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(BOOST_SPIRIT_TRAVERSE_HPP)
+#define BOOST_SPIRIT_TRAVERSE_HPP
+
+#include <boost/spirit/home/classic/namespace.hpp>
+#include <boost/spirit/home/classic/meta/impl/traverse.ipp>
+
+namespace boost { namespace spirit {
+
+BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
+
+    ///////////////////////////////////////////////////////////////////////////
+    //
+    //  Post-order traversal of auxilliary parsers.
+    //
+    ///////////////////////////////////////////////////////////////////////////
+    struct post_order
+    {
+        //  Return the parser type, which is generated as the result of the
+        //  traverse function below.
+
+        template <typename MetaT, typename ParserT>
+        struct result
+        {
+            typedef typename
+                traverse_post_order_return<
+                    MetaT
+                  , ParserT
+                  , traverse_post_order_env<0, 0, 0, 0>
+                >::type
+            type;
+        };
+
+        //  Traverse a given parser and refactor it with the help of the given
+        //  MetaT metafunction template.
+
+        template <typename MetaT, typename ParserT>
+        static typename result<MetaT, ParserT>::type
+        traverse(MetaT const &meta_, ParserT const &parser_)
+        {
+            typedef typename ParserT::parser_category_t parser_category_t;
+            return impl::traverse_post_order<parser_category_t>::generate(
+                meta_, parser_, traverse_post_order_env<0, 0, 0, 0>());
+        }
+    };
+
+    ///////////////////////////////////////////////////////////////////////////
+    //
+    //  Transform policies
+    //
+    //      The following policy classes could be used to assemble some new
+    //      transformation metafunction which uses identity transformations
+    //      for some parser_category type parsers.
+    //
+    ///////////////////////////////////////////////////////////////////////////
+
+    ///////////////////////////////////////////////////////////////////////////
+    //  transform plain parsers
+    template <typename TransformT>
+    struct plain_identity_policy
+    {
+        template <typename ParserT, typename EnvT>
+        struct plain_result
+        {
+            // plain parsers should be embedded and returned correctly
+            typedef typename ParserT::embed_t type;
+        };
+
+        template <typename ParserT, typename EnvT>
+        typename parser_traversal_plain_result<TransformT, ParserT, EnvT>::type
+        generate_plain(ParserT const &parser_, EnvT const& /*env*/) const
+        {
+            return parser_;
+        }
+    };
+
+    //////////////////////////////////
+    //  transform unary parsers
+    template <typename UnaryT, typename SubjectT>
+    struct unary_identity_policy_return
+    {
+        typedef typename UnaryT::parser_generator_t parser_generator_t;
+        typedef typename parser_generator_t
+            ::template result<SubjectT>::type type;
+    };
+
+    template <typename TransformT>
+    struct unary_identity_policy
+    {
+        template <typename UnaryT, typename SubjectT, typename EnvT>
+        struct unary_result
+        {
+            typedef
+                typename unary_identity_policy_return<UnaryT, SubjectT>::type
+            type;
+        };
+
+        template <typename UnaryT, typename SubjectT, typename EnvT>
+        typename parser_traversal_unary_result<
+            TransformT, UnaryT, SubjectT, EnvT>::type
+        generate_unary(
+            UnaryT const &, SubjectT const &subject_, EnvT const& /*env*/) const
+        {
+            typedef typename UnaryT::parser_generator_t parser_generator_t;
+            return parser_generator_t::template generate<SubjectT>(subject_);
+        }
+    };
+
+    //////////////////////////////////
+    //  transform action parsers
+    template <typename TransformT>
+    struct action_identity_policy
+    {
+        template <typename ActionT, typename SubjectT, typename EnvT>
+        struct action_result
+        {
+            typedef action<SubjectT, typename ActionT::predicate_t> type;
+        };
+
+        template <typename ActionT, typename SubjectT, typename EnvT>
+        typename parser_traversal_action_result<
+            TransformT, ActionT, SubjectT, EnvT
+        >::type
+        generate_action(ActionT const &action_, SubjectT const &subject_,
+            EnvT const& /*env*/) const
+        {
+            return subject_[action_.predicate()];
+        }
+    };
+
+    //////////////////////////////////
+    //  transform binary parsers
+    template <typename BinaryT, typename LeftT, typename RightT>
+    struct binary_identity_policy_return
+    {
+        typedef typename BinaryT::parser_generator_t parser_generator_t;
+        typedef typename parser_generator_t
+            ::template result<LeftT, RightT>::type type;
+    };
+
+    template <typename TransformT>
+    struct binary_identity_policy
+    {
+        template <typename BinaryT, typename LeftT
+            , typename RightT, typename EnvT>
+        struct binary_result {
+
+            typedef typename
+                binary_identity_policy_return<BinaryT, LeftT, RightT>::type
+            type;
+        };
+
+        template <typename BinaryT, typename LeftT
+            , typename RightT, typename EnvT>
+        typename parser_traversal_binary_result<
+            TransformT, BinaryT, LeftT, RightT, EnvT
+        >::type
+        generate_binary(
+            BinaryT const &, LeftT const& left_
+          , RightT const& right_, EnvT const& /*env*/) const
+        {
+            typedef typename BinaryT::parser_generator_t parser_generator_t;
+            return parser_generator_t::
+                template generate<LeftT, RightT>(left_, right_);
+        }
+    };
+
+    ///////////////////////////////////////////////////////////////////////////
+    //
+    //  transform_policies template
+    //
+    //      The transform_policies template metafunction could serve as a
+    //      base class for new metafunctions to be passed to the traverse meta
+    //      template (see above), where only minimal parts have to be
+    //      overwritten.
+    //
+    ///////////////////////////////////////////////////////////////////////////
+
+    template <
+        typename TransformT,
+        typename PlainPolicyT = plain_identity_policy<TransformT>,
+        typename UnaryPolicyT = unary_identity_policy<TransformT>,
+        typename ActionPolicyT = action_identity_policy<TransformT>,
+        typename BinaryPolicyT = binary_identity_policy<TransformT>
+    >
+    struct transform_policies :
+        public PlainPolicyT,
+        public UnaryPolicyT,
+        public ActionPolicyT,
+        public BinaryPolicyT
+    {
+    };
+
+    ///////////////////////////////////////////////////////////////////////////
+    //
+    //  Identity transformation
+    //
+    //      The identity_transform metafunction supplied to the traverse
+    //      template will generate a new parser, which will be exactly
+    //      identical to the parser given as the parameter to the traverse
+    //      metafunction. I.e. the following conceptual 'equation' will be
+    //      always true:
+    //
+    //      some_parser ==
+    //          post_order::traverse(identity_transform(), some_parser)
+    //
+    ///////////////////////////////////////////////////////////////////////////
+
+    struct identity_transform : transform_policies<identity_transform> {};
+
+BOOST_SPIRIT_CLASSIC_NAMESPACE_END
+
+}} // namespace BOOST_SPIRIT_CLASSIC_NS
+
+#endif // !defined(BOOST_SPIRIT_TRAVERSE_HPP)