data/stack.hh

   1 # C++ skeleton for Bison
   2
   3 # Copyright (C) 2002-2015 Free Software Foundation, Inc.
   4
   5 # This program is free software: you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation, either version 3 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 m4_pushdef([b4_copyright_years],
  19            [2002-2015])
  20
  21 # b4_stack_define
  22 # ---------------
  23 m4_define([b4_stack_define],
  24 [[  /// A stack with random access from its top.
  25   template <class T, class S = std::vector<T> >
  26   class stack
  27   {
  28   public:
  29     // Hide our reversed order.
  30     typedef typename S::reverse_iterator iterator;
  31     typedef typename S::const_reverse_iterator const_iterator;
  32
  33     stack ()
  34       : seq_ ()
  35     {
  36       seq_.reserve (200);
  37     }
  38
  39     stack (unsigned n)
  40       : seq_ (n)
  41     {}
  42
  43     /// Random access.
  44     ///
  45     /// Index 0 returns the topmost element.
  46     T&
  47     operator[] (unsigned i)
  48     {
  49       return seq_[seq_.size () - 1 - i];
  50     }
  51
  52     /// Random access.
  53     ///
  54     /// Index 0 returns the topmost element.
  55     const T&
  56     operator[] (unsigned i) const
  57     {
  58       return seq_[seq_.size () - 1 - i];
  59     }
  60
  61     /// Steal the contents of \a t.
  62     ///
  63     /// Close to move-semantics.
  64     void
  65     push (T& t)
  66     {
  67       seq_.push_back (T());
  68       operator[](0).move (t);
  69     }
  70
  71     void
  72     pop (unsigned n = 1)
  73     {
  74       for (; n; --n)
  75         seq_.pop_back ();
  76     }
  77
  78     void
  79     clear ()
  80     {
  81       seq_.clear ();
  82     }
  83
  84     typename S::size_type
  85     size () const
  86     {
  87       return seq_.size ();
  88     }
  89
  90     const_iterator
  91     begin () const
  92     {
  93       return seq_.rbegin ();
  94     }
  95
  96     const_iterator
  97     end () const
  98     {
  99       return seq_.rend ();
 100     }
 101
 102   private:
 103     stack (const stack&);
 104     stack& operator= (const stack&);
 105     /// The wrapped container.
 106     S seq_;
 107   };
 108
 109   /// Present a slice of the top of a stack.
 110   template <class T, class S = stack<T> >
 111   class slice
 112   {
 113   public:
 114     slice (const S& stack, unsigned range)
 115       : stack_ (stack)
 116       , range_ (range)
 117     {}
 118
 119     const T&
 120     operator [] (unsigned i) const
 121     {
 122       return stack_[range_ - i];
 123     }
 124
 125   private:
 126     const S& stack_;
 127     unsigned range_;
 128   };
 129 ]])
 130
 131 b4_defines_if(
 132 [b4_output_begin([b4_dir_prefix[]stack.hh])
 133 b4_copyright([Stack handling for Bison parsers in C++])[
 134
 135 /**
 136  ** \file ]b4_dir_prefix[stack.hh
 137  ** Define the ]b4_namespace_ref[::stack class.
 138  */
 139
 140 ]b4_cpp_guard_open([b4_dir_prefix[]stack.hh])[
 141
 142 # include <vector>
 143
 144 ]b4_namespace_open[
 145 ]b4_stack_define[
 146 ]b4_namespace_close[
 147
 148 ]b4_cpp_guard_close([b4_dir_prefix[]stack.hh])
 149 b4_output_end()
 150 ])
 151
 152 m4_popdef([b4_copyright_years])