comparison DEPENDENCIES/generic/include/boost/icl/detail/element_comparer.hpp @ 16:2665513ce2d3

Add boost headers

+/*-----------------------------------------------------------------------------+
+Copyright (c) 2008-2009: Joachim Faulhaber
++------------------------------------------------------------------------------+
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENCE.txt or copy at
+           http://www.boost.org/LICENSE_1_0.txt)
++-----------------------------------------------------------------------------*/
+#ifndef BOOST_ICL_ELEMENT_COMPARER_HPP_JOFA_090202
+#define BOOST_ICL_ELEMENT_COMPARER_HPP_JOFA_090202
+
+#include <boost/mpl/and.hpp>
+#include <boost/icl/type_traits/is_map.hpp>
+#include <boost/icl/detail/notate.hpp>
+#include <boost/icl/type_traits/identity_element.hpp>
+
+namespace boost{namespace icl
+{
+
+namespace Interval_Set
+{
+
+template<class LeftT, class RightT>
+class element_comparer
+{
+public:
+    typedef typename LeftT::const_iterator  LeftIterT;
+    typedef typename RightT::const_iterator RightIterT;
+
+    BOOST_STATIC_CONSTANT(bool, 
+        _compare_codomain = (mpl::and_<is_map<LeftT>, is_map<RightT> >::value)); 
+
+    element_comparer(const LeftT&      left,
+                     const RightT&     right,
+                     const LeftIterT&  left_end,
+                     const RightIterT& right_end)
+        : _left(left), _right(right),
+          _left_end(left_end), _right_end(right_end), _result(equal)
+    {}
+
+    enum{nextboth, nextleft, nextright, stop};
+
+    enum
+    {
+        less    = comparison::less, 
+        equal   = comparison::equal, 
+        greater = comparison::greater
+    };
+
+    int result()const{ return _result; }
+
+    bool covalues_are_equal(LeftIterT& left, RightIterT& right)
+    {
+        if(co_value<LeftT>(left) < co_value<RightT>(right))
+            _result = less;
+        if(co_value<RightT>(right) < co_value<LeftT>(left))
+            _result = greater;
+        return _result == equal;
+    }
+
+    int proceed(LeftIterT& left, RightIterT& right)
+    {
+        if(upper_less(key_value<LeftT>(left), key_value<RightT>(right)))
+        {
+            _prior_left = left;
+            ++left;
+            return nextleft;
+        }
+        else if(upper_less(key_value<RightT>(right), key_value<LeftT>(left)))
+        {
+            _prior_right = right;
+            ++right;
+            return nextright;
+        }
+        else
+        {
+            ++left; 
+            ++right;    
+            return nextboth;
+        }
+    }
+
+    int next_both(LeftIterT& left, RightIterT& right)
+    {
+        if(left == _left_end)
+        {
+            _result = (right == _right_end) ? equal : less;
+            return stop;
+        }
+
+        // left != _left_end
+        if(right == _right_end)
+        {
+            _result = greater;
+            return stop;
+        }
+
+        // The starting intervals have to begin equally
+        if(lower_less(key_value<LeftT>(left), key_value<RightT>(right)))
+        {   // left: same A... = sameA...
+            // right:same  B.. = sameB...
+            _result = less;
+            return stop;
+        }
+
+        if(lower_less(key_value<LeftT>(right), key_value<RightT>(left)))
+        {   // left: same  B.. = sameB...
+            // right:same A... = sameA...
+            _result = greater;
+            return stop;
+        }
+
+        if(_compare_codomain && !covalues_are_equal(left, right))
+            return stop;
+
+        return proceed(left, right);
+    }
+
+    int next_left(LeftIterT& left, RightIterT& right)
+    {
+        if(left == _left_end)
+        {   // left: same
+            // right:sameA...
+            _result = less;
+            return stop;
+        }
+
+        if(!key_value<LeftT>(_prior_left).touches(key_value<LeftT>(left)))
+        {   // left: same B = sameB...
+            // right:sameA  = sameA...
+            _result = greater;
+            return stop;
+        }
+
+        if(_compare_codomain && !covalues_are_equal(left, right))
+            return stop;
+
+        return proceed(left, right);
+    }
+
+    int next_right(LeftIterT& left, RightIterT& right)
+    {
+        if(right == _right_end)
+        {   // left: sameA...
+            // right:same
+            _result = greater;
+            return stop;
+        }
+
+        if(!key_value<RightT>(_prior_right).touches(key_value<RightT>(right)))
+        {
+            // left: sameA... = sameA...
+            // right:same B.. = sameB...
+            _result = less;
+            return stop;
+        }
+
+        if(_compare_codomain && !covalues_are_equal(left, right))
+            return stop;
+
+        return proceed(left, right);
+    }
+
+private:
+    const LeftT&  _left;
+    const RightT& _right;
+    LeftIterT     _left_end;
+    RightIterT    _right_end;
+    LeftIterT     _prior_left;
+    RightIterT    _prior_right;
+    int           _result;
+};
+
+
+
+template<class LeftT, class RightT>
+int element_compare
+(
+    const LeftT& left,   //sub
+    const RightT& right, //super
+    typename LeftT::const_iterator  left_begin,   
+    typename LeftT::const_iterator  left_end,
+    typename RightT::const_iterator right_begin, 
+    typename RightT::const_iterator right_end
+)
+{
+    typedef element_comparer<LeftT,RightT> Step;
+    Step step(left, right, left_end, right_end);
+
+    typename LeftT::const_iterator  left_  = left_begin;
+    typename RightT::const_iterator right_ = right_begin;
+
+    int state = Step::nextboth;
+    while(state != Step::stop)
+    {
+        switch(state){
+        case Step::nextboth:  state = step.next_both (left_, right_); break;
+        case Step::nextleft:  state = step.next_left (left_, right_); break;
+        case Step::nextright: state = step.next_right(left_, right_); break;
+        }
+    }
+    return step.result();
+}
+
+
+} // namespace Interval_Set
+    
+}} // namespace icl boost
+
+#endif 
+