From fd64eec23d5952bca457ea52f2ccd61eda166138 Mon Sep 17 00:00:00 2001
From: Tobias Schwinger <tschwinger@isonews2.com>
Date: Mon, 19 Mar 2007 21:03:35 +0000
Subject: [PATCH] adds repetitive_view

[SVN r37233]
---
 .../fusion/sequence/view/repetitive_view.hpp  | 15 ++++
 .../repetitive_view/detail/begin_impl.hpp     | 49 ++++++++++
 .../repetitive_view/detail/deref_impl.hpp     | 44 +++++++++
 .../view/repetitive_view/detail/end_impl.hpp  | 49 ++++++++++
 .../view/repetitive_view/detail/next_impl.hpp | 90 +++++++++++++++++++
 .../repetitive_view/detail/value_of_impl.hpp  | 34 +++++++
 .../view/repetitive_view/repetitive_view.hpp  | 48 ++++++++++
 .../repetitive_view/repetitive_view_fwd.hpp   | 19 ++++
 .../repetitive_view_iterator.hpp              | 50 +++++++++++
 9 files changed, 398 insertions(+)
 create mode 100644 include/boost/fusion/sequence/view/repetitive_view.hpp
 create mode 100644 include/boost/fusion/sequence/view/repetitive_view/detail/begin_impl.hpp
 create mode 100644 include/boost/fusion/sequence/view/repetitive_view/detail/deref_impl.hpp
 create mode 100644 include/boost/fusion/sequence/view/repetitive_view/detail/end_impl.hpp
 create mode 100644 include/boost/fusion/sequence/view/repetitive_view/detail/next_impl.hpp
 create mode 100644 include/boost/fusion/sequence/view/repetitive_view/detail/value_of_impl.hpp
 create mode 100644 include/boost/fusion/sequence/view/repetitive_view/repetitive_view.hpp
 create mode 100644 include/boost/fusion/sequence/view/repetitive_view/repetitive_view_fwd.hpp
 create mode 100644 include/boost/fusion/sequence/view/repetitive_view/repetitive_view_iterator.hpp

diff --git a/include/boost/fusion/sequence/view/repetitive_view.hpp b/include/boost/fusion/sequence/view/repetitive_view.hpp
new file mode 100644
index 00000000..8940174b
--- /dev/null
+++ b/include/boost/fusion/sequence/view/repetitive_view.hpp
@@ -0,0 +1,15 @@
+/*=============================================================================
+    Copyright (c) 2007 Tobias Schwinger
+
+    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_FUSION_REPETITIVE_VIEW_HPP_INCLUDED)
+#define BOOST_FUSION_REPETITIVE_VIEW_HPP_INCLUDED
+
+#include <boost/fusion/sequence/view/repetitive_view/repetitive_view.hpp>
+#include <boost/fusion/sequence/view/repetitive_view/repetitive_view_iterator.hpp>
+
+#endif
+
diff --git a/include/boost/fusion/sequence/view/repetitive_view/detail/begin_impl.hpp b/include/boost/fusion/sequence/view/repetitive_view/detail/begin_impl.hpp
new file mode 100644
index 00000000..b5c4c29a
--- /dev/null
+++ b/include/boost/fusion/sequence/view/repetitive_view/detail/begin_impl.hpp
@@ -0,0 +1,49 @@
+/*=============================================================================
+    Copyright (c) 2007 Tobias Schwinger
+
+    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_FUSION_REPETITIVE_VIEW_BEGIN_IMPL_HPP_INCLUDED)
+#define BOOST_FUSION_REPETITIVE_VIEW_BEGIN_IMPL_HPP_INCLUDED
+
+#include <boost/fusion/sequence/intrinsic/begin.hpp>
+#include <boost/fusion/sequence/view/repetitive_view/repetitive_view_fwd.hpp>
+
+namespace boost { namespace fusion
+{
+    struct repetitive_view_tag;
+
+    template <typename Sequence, typename Pos>
+    struct repetitive_view_iterator;
+
+    namespace extension
+    {
+        template<typename Tag>
+        struct begin_impl;
+
+        template<>
+        struct begin_impl<repetitive_view_tag>
+        {
+            template<typename View>
+            struct apply
+            {
+                typedef typename View::sequence_type sequence_type;
+
+                typedef repetitive_view_iterator<sequence_type,
+                    typename result_of::begin<sequence_type>::type > type;
+
+                static type call(View const& v)
+                {
+                    return type(v.seq);
+                }
+            };
+        };
+
+    }
+
+}}
+
+#endif
+
diff --git a/include/boost/fusion/sequence/view/repetitive_view/detail/deref_impl.hpp b/include/boost/fusion/sequence/view/repetitive_view/detail/deref_impl.hpp
new file mode 100644
index 00000000..2c0caf80
--- /dev/null
+++ b/include/boost/fusion/sequence/view/repetitive_view/detail/deref_impl.hpp
@@ -0,0 +1,44 @@
+/*=============================================================================
+    Copyright (c) 2007 Tobias Schwinger
+
+    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_FUSION_REPETITIVE_VIEW_DEREF_IMPL_HPP_INCLUDED)
+#define BOOST_FUSION_REPETITIVE_VIEW_DEREF_IMPL_HPP_INCLUDED
+
+#include <boost/fusion/iterator/deref.hpp>
+
+namespace boost { namespace fusion
+{
+    struct repetitive_view_iterator_tag;
+
+    namespace extension
+    {
+        template<typename Tag>
+        struct deref_impl;
+
+        template<>
+        struct deref_impl<repetitive_view_iterator_tag>
+        {
+            template<typename Iterator>
+            struct apply
+            {
+                typedef typename
+                    result_of::deref<typename Iterator::pos_type>::type
+                type;
+
+                static type call(Iterator const& i)
+                {
+                    return *i.pos;
+                }
+            };
+        };
+
+    }
+
+}}
+
+#endif
+
diff --git a/include/boost/fusion/sequence/view/repetitive_view/detail/end_impl.hpp b/include/boost/fusion/sequence/view/repetitive_view/detail/end_impl.hpp
new file mode 100644
index 00000000..00ac0874
--- /dev/null
+++ b/include/boost/fusion/sequence/view/repetitive_view/detail/end_impl.hpp
@@ -0,0 +1,49 @@
+/*=============================================================================
+    Copyright (c) 2007 Tobias Schwinger
+
+    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_FUSION_REPETITIVE_VIEW_END_IMPL_HPP_INCLUDED)
+#define BOOST_FUSION_REPETITIVE_VIEW_END_IMPL_HPP_INCLUDED
+
+#include <boost/fusion/sequence/intrinsic/end.hpp>
+#include <boost/fusion/sequence/view/repetitive_view/repetitive_view_fwd.hpp>
+
+namespace boost { namespace fusion
+{
+    struct repetitive_view_tag;
+
+    template <typename Sequence, typename Pos>
+    struct repetitive_view_iterator;
+
+    namespace extension
+    {
+        template<typename Tag>
+        struct end_impl;
+
+        template<>
+        struct end_impl<repetitive_view_tag>
+        {
+            template<typename View>
+            struct apply
+            {
+                typedef typename View::sequence_type sequence_type;
+
+                typedef repetitive_view_iterator<sequence_type,
+                    typename result_of::end<sequence_type>::type > type;
+
+                static type call(View const& v)
+                {
+                    return type(v.seq,end(v.seq));
+                }
+            };
+        };
+
+    }
+
+}}
+
+#endif
+
diff --git a/include/boost/fusion/sequence/view/repetitive_view/detail/next_impl.hpp b/include/boost/fusion/sequence/view/repetitive_view/detail/next_impl.hpp
new file mode 100644
index 00000000..b629cb01
--- /dev/null
+++ b/include/boost/fusion/sequence/view/repetitive_view/detail/next_impl.hpp
@@ -0,0 +1,90 @@
+/*=============================================================================
+    Copyright (c) 2007 Tobias Schwinger
+
+    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_FUSION_REPETITIVE_VIEW_NEXT_IMPL_HPP_INCLUDED)
+#define BOOST_FUSION_REPETITIVE_VIEW_NEXT_IMPL_HPP_INCLUDED
+
+#include <boost/fusion/iterator/next.hpp>
+#include <boost/fusion/iterator/equal_to.hpp>
+
+namespace boost { namespace fusion
+{
+    struct repetitive_view_iterator_tag;
+
+    template <typename Sequence, typename Pos>
+    struct repetitive_view_iterator;
+
+    namespace extension
+    {
+        template <typename Tag>
+        struct next_impl;
+
+        template <>
+        struct next_impl<repetitive_view_iterator_tag>
+        {
+            template<typename Iterator, 
+                bool Last = result_of::equal_to<typename Iterator::end_type,
+                    typename result_of::next<
+                        typename Iterator::pos_type
+                    >::type>::value > 
+            struct apply_nonempty // <Iterator,false>
+            {
+                // advanvce to next position
+
+                typedef repetitive_view_iterator<
+                    typename Iterator::sequence_type,
+                    typename result_of::next<typename Iterator::pos_type>::type
+                    >
+                type;
+
+                static type call(Iterator const& i)
+                {
+                    return type(i.seq, next(i.pos));
+                }
+            };
+            template <typename Iterator>
+            struct apply_nonempty<Iterator,true>
+            {
+                // reset to beginning
+
+                typedef repetitive_view_iterator<
+                    typename Iterator::sequence_type,
+                    typename Iterator::first_type
+                    > 
+                type;
+
+                static type call(Iterator const& i)
+                {
+                    return type(i.seq);
+                }    
+            };
+
+            template <typename Iterator,
+                bool Empty = result_of::equal_to<typename Iterator::end_type,
+                    typename Iterator::pos_type>::value >
+            struct apply // <Iterator,false>
+                : apply_nonempty<Iterator>
+            { };
+
+            template <typename Iterator>
+            struct apply<Iterator,true>
+            {
+                // eps^n = eps
+
+                typedef Iterator type;
+
+                static type call(Iterator const& i)
+                {
+                    return type(i);
+                }
+            };
+        };
+    }
+}}
+
+#endif
+
diff --git a/include/boost/fusion/sequence/view/repetitive_view/detail/value_of_impl.hpp b/include/boost/fusion/sequence/view/repetitive_view/detail/value_of_impl.hpp
new file mode 100644
index 00000000..bf5f2f06
--- /dev/null
+++ b/include/boost/fusion/sequence/view/repetitive_view/detail/value_of_impl.hpp
@@ -0,0 +1,34 @@
+/*=============================================================================
+    Copyright (c) 2007 Tobias Schwinger
+
+    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_FUSION_REPETITIVE_VIEW_VALUE_OF_IMPL_HPP_INCLUDED)
+#define BOOST_FUSION_REPETITIVE_VIEW_VALUE_OF_IMPL_HPP_INCLUDED
+
+#include <boost/fusion/iterator/value_of.hpp>
+
+namespace boost { namespace fusion
+{
+    struct repetitive_view_iterator_tag;
+
+    namespace extension
+    {
+        template<typename Tag>
+        struct value_of_impl;
+
+        template<>
+        struct value_of_impl<repetitive_view_iterator_tag>
+        {
+            template<typename Iterator>
+            struct apply
+                : result_of::value_of<typename Iterator::pos_type>
+            { };
+        };
+    }
+}}
+
+#endif
+
diff --git a/include/boost/fusion/sequence/view/repetitive_view/repetitive_view.hpp b/include/boost/fusion/sequence/view/repetitive_view/repetitive_view.hpp
new file mode 100644
index 00000000..2e06fd80
--- /dev/null
+++ b/include/boost/fusion/sequence/view/repetitive_view/repetitive_view.hpp
@@ -0,0 +1,48 @@
+/*=============================================================================
+    Copyright (c) 2007 Tobias Schwinger
+
+    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_FUSION_REPETITIVE_REPETITIVE_VIEW_VIEW_HPP_INCLUDED)
+#define BOOST_FUSION_REPETITIVE_VIEW_REPETITIVE_VIEW_HPP_INCLUDED
+
+#include <boost/type_traits/remove_reference.hpp>
+#include <boost/mpl/if.hpp>
+
+#include <boost/fusion/support/is_view.hpp>
+#include <boost/fusion/support/category_of.hpp>
+
+#include <boost/fusion/sequence/view/repetitive_view/detail/begin_impl.hpp>
+#include <boost/fusion/sequence/view/repetitive_view/detail/end_impl.hpp>
+
+
+namespace boost { namespace fusion
+{
+    struct repetitive_view_tag;
+    struct fusion_sequence_tag;
+
+    template<typename Sequence> struct repetitive_view 
+        : sequence_base< repetitive_view<Sequence> >
+    {
+        typedef repetitive_view_tag fusion_tag;
+        typedef fusion_sequence_tag tag; // this gets picked up by MPL
+        typedef mpl::true_ is_view;
+
+        typedef single_pass_traversal_tag category;
+
+        typedef typename boost::remove_reference<Sequence>::type sequence_type;
+        typedef typename 
+            mpl::if_<traits::is_view<Sequence>, Sequence, sequence_type&>::type
+        stored_seq_type;
+
+        repetitive_view(Sequence& seq)
+            : seq(seq) {}
+
+        stored_seq_type seq;
+    };
+
+}}
+
+#endif
diff --git a/include/boost/fusion/sequence/view/repetitive_view/repetitive_view_fwd.hpp b/include/boost/fusion/sequence/view/repetitive_view/repetitive_view_fwd.hpp
new file mode 100644
index 00000000..24e146c0
--- /dev/null
+++ b/include/boost/fusion/sequence/view/repetitive_view/repetitive_view_fwd.hpp
@@ -0,0 +1,19 @@
+/*=============================================================================
+    Copyright (c) 2007 Tobias Schwinger
+
+    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_FUSION_REPETITIVE_VIEW_FWD_HPP_INCLUDED)
+#define BOOST_FUSION_REPETITIVE_VIEW_FWD_HPP_INCLUDED
+
+namespace boost { namespace fusion
+{
+    struct repetitive_view_tag;
+
+    template<typename Sequence> struct repetitive_view;
+}}
+
+#endif
+
diff --git a/include/boost/fusion/sequence/view/repetitive_view/repetitive_view_iterator.hpp b/include/boost/fusion/sequence/view/repetitive_view/repetitive_view_iterator.hpp
new file mode 100644
index 00000000..6b2a9a5e
--- /dev/null
+++ b/include/boost/fusion/sequence/view/repetitive_view/repetitive_view_iterator.hpp
@@ -0,0 +1,50 @@
+/*=============================================================================
+    Copyright (c) 2007 Tobias Schwinger
+
+    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_FUSION_REPETITIVE_VIEW_ITERATOR_HPP_INCLUDED)
+#define BOOST_FUSION_REPETITIVE_VIEW_HPP_ITERATOR_INCLUDED
+
+#include <boost/fusion/support/iterator_base.hpp>
+#include <boost/fusion/support/category_of.hpp>
+#include <boost/fusion/iterator/mpl/convert_iterator.hpp>
+#include <boost/fusion/sequence/intrinsic/begin.hpp>
+#include <boost/fusion/sequence/intrinsic/end.hpp>
+#include <boost/fusion/sequence/view/repetitive_view/detail/deref_impl.hpp>
+#include <boost/fusion/sequence/view/repetitive_view/detail/next_impl.hpp>
+#include <boost/fusion/sequence/view/repetitive_view/detail/value_of_impl.hpp>
+
+namespace boost { namespace fusion
+{
+    struct repetitive_view_iterator_tag;
+
+    template<typename Sequence, typename Pos = 
+        typename result_of::begin<Sequence>::type>
+    struct repetitive_view_iterator
+        : iterator_base< repetitive_view_iterator<Sequence,Pos> >
+    {
+        typedef repetitive_view_iterator_tag fusion_tag;
+
+        typedef Sequence sequence_type;
+        typedef typename convert_iterator<Pos>::type pos_type;
+        typedef typename convert_iterator<typename result_of::begin<Sequence>::type>::type first_type;
+        typedef typename convert_iterator<typename result_of::end<Sequence>::type>::type end_type;
+        typedef single_pass_traversal_tag category;
+
+        explicit repetitive_view_iterator(Sequence& seq)
+            : seq(seq), pos(begin(seq)) {}
+
+        repetitive_view_iterator(Sequence& seq, pos_type const& pos)
+            : seq(seq), pos(pos) {}
+
+        Sequence& seq;
+        pos_type pos;
+
+    };
+}}
+
+#endif
+