text: /* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
  /*
   *  Main authors:
   *     Christian Schulte <schulte@gecode.org>
   *
   *  Copyright:
   *     Christian Schulte, 2011
   *
   *  Last modified:
   *     $Date$ by $Author$
   *     $Revision$
   *
   *  This file is part of Gecode, the generic constraint
   *  development environment:
   *     http://www.gecode.org
   *
   *  Permission is hereby granted, free of charge, to any person obtaining
   *  a copy of this software and associated documentation files (the
   *  "Software"), to deal in the Software without restriction, including
   *  without limitation the rights to use, copy, modify, merge, publish,
   *  distribute, sublicense, and/or sell copies of the Software, and to
   *  permit persons to whom the Software is furnished to do so, subject to
   *  the following conditions:
   *
   *  The above copyright notice and this permission notice shall be
   *  included in all copies or substantial portions of the Software.
   *
   *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
   *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
   *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
   *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   *
   */
  
  #include <gecode/int/rel.hh>
  
  namespace Gecode { namespace Int { namespace Member {
  
    template<class View>
    forceinline
    Prop<View>::Prop(Home home, ValSet& vs0, ViewArray<View>& x, View y)
      : NaryOnePropagator<View,PC_INT_DOM>(home,x,y),
        vs(vs0) {}
  
    template<class View>
    forceinline void
    Prop<View>::add(Space& home, ValSet& vs, ViewArray<View>& x) {
      int n=x.size();
      for (int i=n; i--; )
        if (x[i].assigned()) {
          vs.add(home, x[i].val());
          x[i] = x[--n];
        }
      x.size(n);
    }
  
    template<class View>
    forceinline void
    Prop<View>::eliminate(Space& home) {
      int n=x.size();
      for (int i=n; i--; )
        if ((rtest_eq_dom(x[i],y) == RT_FALSE) || vs.subset(x[i])) {
          // x[i] is different from y or values are contained in vs
          x[i].cancel(home, *this, PC_INT_DOM);
          x[i] = x[--n];
        }
      x.size(n);
    }
  
    template<class View>
    inline ExecStatus
    Prop<View>::post(Home home, ViewArray<View>& x, View y) {
      if (x.size() == 0)
        return ES_FAILED;
  
      x.unique(home);
  
      if (x.size() == 1)
        return Rel::EqDom<View,View>::post(home,x[0],y);
  
      if (x.same(home,y))
        return ES_OK;
  
      // Eliminate assigned views and store them into the value set
      ValSet vs;
      add(home, vs, x);
  
      if (x.size() == 0) {
        ValSet::Ranges vsr(vs);
        GECODE_ME_CHECK(y.inter_r(home,vsr,false));
        return ES_OK;
      }
  
      (void) new (home) Prop<View>(home, vs, x, y);
      return ES_OK;
    }
  
    template<class View>
    forceinline ExecStatus
    Prop<View>::post(Home home, ValSet& vs, ViewArray<View>& x, View y) {
      (void) new (home) Prop<View>(home, vs, x, y);
      return ES_OK;
    }
  
    template<class View>
    forceinline
    Prop<View>::Prop(Space& home, bool share, Prop<View>& p)
      : NaryOnePropagator<View,PC_INT_DOM>(home, share, p) {
      vs.update(home, share, p.vs);
    }
  
    template<class View>
    Propagator*
    Prop<View>::copy(Space& home, bool share) {
      return new (home) Prop<View>(home, share, *this);
    }
  
    template<class View>
    forceinline size_t
    Prop<View>::dispose(Space& home) {
      vs.dispose(home);
      (void) NaryOnePropagator<View,PC_INT_DOM>::dispose(home);
      return sizeof(*this);
    }
  
    template<class View>
    PropCost
    Prop<View>::cost(const Space&, const ModEventDelta&) const {
      return PropCost::linear(PropCost::HI, x.size()+1);
    }
  
    template<class View>
    ExecStatus
    Prop<View>::propagate(Space& home, const ModEventDelta& med) {
      // Add assigned views to value set
      if (View::me(med) == ME_INT_VAL)
        add(home,vs,x);
  
      // Eliminate views from x
      eliminate(home);
  
      if (x.size() == 0) {
        // y must have values in the value set
        ValSet::Ranges vsr(vs);
        GECODE_ME_CHECK(y.inter_r(home,vsr,false));
        return home.ES_SUBSUMED(*this);
      }
  
      // Constrain y to union of x and value set
      Region r(home);
  
      assert(x.size() > 0);
      ValSet::Ranges vsr(vs);
      ViewRanges<View> xsr(x[x.size()-1]);
      Iter::Ranges::NaryUnion  u(r,vsr,xsr);
      for (int i=x.size()-1; i--; ) {
        ViewRanges<View> xir(x[i]);
        u |= xir;
      }
  
      GECODE_ME_CHECK(y.inter_r(home,u,false));
  
      // Check whether all values in y are already in the value set
      if (vs.subset(y))
        return home.ES_SUBSUMED(*this);
  
      return ES_FIX;
    }
  
  }}}
  
  // STATISTICS: int-prop
  