ceph/src/boost/boost/spirit/home/classic/iterator/impl/position_iterator.ipp

   1 /*=============================================================================
   2     Copyright (c) 2002 Juan Carlos Arevalo-Baeza
   3     Copyright (c) 2002-2006 Hartmut Kaiser
   4     Copyright (c) 2003 Giovanni Bajo
   5     http://spirit.sourceforge.net/
   6
   7     Use, modification and distribution is subject to the Boost Software
   8     License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   9     http://www.boost.org/LICENSE_1_0.txt)
  10 =============================================================================*/
  11 #ifndef POSITION_ITERATOR_IPP
  12 #define POSITION_ITERATOR_IPP
  13
  14 #include <boost/config.hpp>
  15 #include <boost/iterator_adaptors.hpp>
  16 #include <boost/type_traits/add_const.hpp>
  17 #include <boost/mpl/if.hpp>
  18 #include <boost/type_traits/is_same.hpp>
  19 #include <boost/spirit/home/classic/core/nil.hpp>  // for nil_t
  20 #include <boost/detail/iterator.hpp> // for boost::detail::iterator_traits
  21
  22 namespace boost { namespace spirit {
  23
  24 BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
  25
  26 ///////////////////////////////////////////////////////////////////////////////
  27 //
  28 //  position_policy<file_position_without_column>
  29 //
  30 //  Specialization to handle file_position_without_column. Only take care of
  31 //  newlines since no column tracking is needed.
  32 //
  33 ///////////////////////////////////////////////////////////////////////////////
  34 template <typename String>
  35 class position_policy<file_position_without_column_base<String> > {
  36
  37 public:
  38     void next_line(file_position_without_column_base<String>& pos)
  39     {
  40         ++pos.line;
  41     }
  42
  43     void set_tab_chars(unsigned int /*chars*/){}
  44     void next_char(file_position_without_column_base<String>& /*pos*/)    {}
  45     void tabulation(file_position_without_column_base<String>& /*pos*/)   {}
  46 };
  47
  48 ///////////////////////////////////////////////////////////////////////////////
  49 //
  50 //  position_policy<file_position>
  51 //
  52 //  Specialization to handle file_position. Track characters and tabulation
  53 //  to compute the current column correctly.
  54 //
  55 //  Default tab size is 4. You can change this with the set_tabchars member
  56 //  of position_iterator.
  57 //
  58 ///////////////////////////////////////////////////////////////////////////////
  59 template <typename String>
  60 class position_policy<file_position_base<String> > {
  61
  62 public:
  63     position_policy()
  64         : m_CharsPerTab(4)
  65     {}
  66
  67     void next_line(file_position_base<String>& pos)
  68     {
  69         ++pos.line;
  70         pos.column = 1;
  71     }
  72
  73     void set_tab_chars(unsigned int chars)
  74     {
  75         m_CharsPerTab = chars;
  76     }
  77
  78     void next_char(file_position_base<String>& pos)
  79     {
  80         ++pos.column;
  81     }
  82
  83     void tabulation(file_position_base<String>& pos)
  84     {
  85         pos.column += m_CharsPerTab - (pos.column - 1) % m_CharsPerTab;
  86     }
  87
  88 private:
  89     unsigned int m_CharsPerTab;
  90 };
  91
  92 /* namespace boost::spirit { */ namespace iterator_ { namespace impl {
  93
  94 ///////////////////////////////////////////////////////////////////////////////
  95 //
  96 //  position_iterator_base_generator
  97 //
  98 //  Metafunction to generate the iterator type using boost::iterator_adaptors,
  99 //  hiding all the metaprogramming thunking code in it. It is used
 100 //  mainly to keep the public interface (position_iterator) cleanear.
 101 //
 102 ///////////////////////////////////////////////////////////////////////////////
 103 template <typename MainIterT, typename ForwardIterT, typename PositionT>
 104 struct position_iterator_base_generator
 105 {
 106 private:
 107     typedef boost::detail::iterator_traits<ForwardIterT> traits;
 108     typedef typename traits::value_type value_type;
 109     typedef typename traits::iterator_category iter_category_t;
 110
 111     // Position iterator is always a non-mutable iterator
 112     typedef typename boost::add_const<value_type>::type const_value_type;
 113
 114 public:
 115     // Check if the MainIterT is nil. If it's nil, it means that the actual
 116     //  self type is position_iterator. Otherwise, it's a real type we
 117     //  must use
 118     typedef typename boost::mpl::if_<
 119         typename boost::is_same<MainIterT, nil_t>::type,
 120         position_iterator<ForwardIterT, PositionT, nil_t>,
 121         MainIterT
 122     >::type main_iter_t;
 123
 124     typedef boost::iterator_adaptor<
 125         main_iter_t,
 126         ForwardIterT,
 127         const_value_type,
 128         boost::forward_traversal_tag
 129     > type;
 130 };
 131
 132 }}
 133
 134 BOOST_SPIRIT_CLASSIC_NAMESPACE_END
 135
 136 }} /* namespace boost::spirit::iterator_::impl */
 137
 138 #endif