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ite.hpp
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33 
34 #include <gecode/float/rel.hh>
35 
36 namespace Gecode { namespace Float { namespace Bool {
37 
38  template<class View>
40  Ite<View>::Ite(Home home, Int::BoolView b0, View y0, View y1, View y2)
41  : Propagator(home), b(b0), x0(y0), x1(y1), x2(y2) {
42  b.subscribe(home,*this,Int::PC_BOOL_VAL);
43  x0.subscribe(home,*this,PC_FLOAT_BND);
44  x1.subscribe(home,*this,PC_FLOAT_BND);
45  x2.subscribe(home,*this,PC_FLOAT_BND);
46  }
47 
48  template<class View>
51  : Propagator(home,p) {
52  b.update(home,p.b);
53  x0.update(home,p.x0);
54  x1.update(home,p.x1);
55  x2.update(home,p.x2);
56  }
57 
58  template<class View>
59  PropCost
60  Ite<View>::cost(const Space&, const ModEventDelta&) const {
62  }
63 
64  template<class View>
65  void
67  b.reschedule(home,*this,Int::PC_BOOL_VAL);
68  x0.reschedule(home,*this,PC_FLOAT_BND);
69  x1.reschedule(home,*this,PC_FLOAT_BND);
70  x2.reschedule(home,*this,PC_FLOAT_BND);
71  }
72 
73  template<class View>
74  forceinline size_t
76  b.cancel(home,*this,Int::PC_BOOL_VAL);
77  x0.cancel(home,*this,PC_FLOAT_BND);
78  x1.cancel(home,*this,PC_FLOAT_BND);
79  x2.cancel(home,*this,PC_FLOAT_BND);
80  (void) Propagator::dispose(home);
81  return sizeof(*this);
82  }
83 
84 
85 
86  template<class View>
87  Actor*
89  return new (home) Ite<View>(home,*this);
90  }
91 
92  template<class View>
93  inline ExecStatus
94  Ite<View>::post(Home home, Int::BoolView b, View x0, View x1, View x2) {
95  if (b.one())
96  return Rel::Eq<View,View>::post(home,x2,x0);
97  if (b.zero())
98  return Rel::Eq<View,View>::post(home,x2,x1);
99  GECODE_ME_CHECK(x2.lq(home,std::max(x0.max(),x1.max())));
100  GECODE_ME_CHECK(x2.gq(home,std::min(x0.min(),x1.min())));
101  (void) new (home) Ite<View>(home,b,x0,x1,x2);
102  return ES_OK;
103  }
104 
105  template<class View>
106  ExecStatus
108  if (b.one())
109  GECODE_REWRITE(*this,(Rel::Eq<View,View>::post(home(*this),x2,x0)));
110  if (b.zero())
111  GECODE_REWRITE(*this,(Rel::Eq<View,View>::post(home(*this),x2,x1)));
112 
113  GECODE_ME_CHECK(x2.lq(home,std::max(x0.max(),x1.max())));
114  GECODE_ME_CHECK(x2.gq(home,std::min(x0.min(),x1.min())));
115 
116  RelTest eq20 = rtest_eq(x2,x0);
117  RelTest eq21 = rtest_eq(x2,x1);
118 
119  if ((eq20 == RT_FALSE) && (eq21 == RT_FALSE))
120  return ES_FAILED;
121 
122  if (eq20 == RT_FALSE) {
123  GECODE_ME_CHECK(b.zero_none(home));
124  if (eq21 == RT_TRUE)
125  return home.ES_SUBSUMED(*this);
126  else
127  GECODE_REWRITE(*this,(Rel::Eq<View,View>::post(home(*this),x2,x1)));
128  }
129 
130  if (eq21 == RT_FALSE) {
131  GECODE_ME_CHECK(b.one_none(home));
132  if (eq20 == RT_TRUE)
133  return home.ES_SUBSUMED(*this);
134  else
135  GECODE_REWRITE(*this,(Rel::Eq<View,View>::post(home(*this),x2,x0)));
136  }
137 
138  if ((eq20 == RT_TRUE) && (eq21 == RT_TRUE))
139  return home.ES_SUBSUMED(*this);
140 
141  return ES_FIX;
142  }
143 
144 }}}
145 
146 // STATISTICS: float-prop
struct Gecode::@602::NNF::@65::@66 b
For binary nodes (and, or, eqv)
int p
Number of positive literals for node type.
Definition: bool-expr.cpp:232
Base-class for both propagators and branchers.
Definition: core.hpp:628
virtual size_t dispose(Space &home)
Delete actor and return its size.
Definition: core.hpp:3252
If-then-else propagator.
Definition: bool.hh:53
virtual PropCost cost(const Space &home, const ModEventDelta &med) const
Cost function (defined as low ternary)
Definition: ite.hpp:60
virtual void reschedule(Space &home)
Schedule function.
Definition: ite.hpp:66
static ExecStatus post(Home home, Int::BoolView b, View x0, View x1, View x2)
Post if-then-else propagator.
Definition: ite.hpp:94
Int::BoolView b
View for condition.
Definition: bool.hh:56
virtual Actor * copy(Space &home)
Copy propagator during cloning.
Definition: ite.hpp:88
virtual size_t dispose(Space &home)
Delete propagator and return its size.
Definition: ite.hpp:75
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: ite.hpp:107
Ite(Space &home, Ite &p)
Constructor for cloning p.
Definition: ite.hpp:50
Binary bounds consistent equality propagator.
Definition: rel.hh:67
static ExecStatus post(Home home, View0 x0, View1 x1)
Post bounds consistent propagator .
Definition: eq.hpp:50
Home class for posting propagators
Definition: core.hpp:856
Boolean view for Boolean variables.
Definition: view.hpp:1380
Propagation cost.
Definition: core.hpp:486
static PropCost ternary(PropCost::Mod m)
Three variables for modifier pcm.
Definition: core.hpp:4805
@ LO
Cheap.
Definition: core.hpp:513
Base-class for propagators.
Definition: core.hpp:1064
Computation spaces.
Definition: core.hpp:1742
void update(Space &home, VarImpView< Var > &y)
Update this view to be a clone of view y.
Definition: view.hpp:567
void subscribe(Space &home, Propagator &p, PropCond pc, bool schedule=true)
Subscribe propagator p with propagation condition pc to view.
Definition: view.hpp:521
ExecStatus
Definition: core.hpp:472
@ ES_OK
Execution is okay.
Definition: core.hpp:476
@ ES_FIX
Propagation has computed fixpoint.
Definition: core.hpp:477
@ ES_FAILED
Execution has resulted in failure.
Definition: core.hpp:474
ExecStatus ES_SUBSUMED(Propagator &p)
Definition: core.hpp:3563
int ModEventDelta
Modification event deltas.
Definition: core.hpp:89
#define GECODE_ME_CHECK(me)
Check whether modification event me is failed, and forward failure.
Definition: macros.hpp:52
#define GECODE_REWRITE(prop, post)
Rewrite propagator by executing post function.
Definition: macros.hpp:116
const FloatNum max
Largest allowed float value.
Definition: float.hh:844
const FloatNum min
Smallest allowed float value.
Definition: float.hh:846
RelTest
Result of testing relation.
Definition: view.hpp:533
@ RT_TRUE
Relation does hold.
Definition: view.hpp:536
@ RT_FALSE
Relation does not hold.
Definition: view.hpp:534
RelTest rtest_eq(View x, View y)
Test whether views x and y are equal.
Definition: rel-test.hpp:40
const Gecode::PropCond PC_FLOAT_BND
Propagate when minimum or maximum of a view changes.
Definition: var-type.hpp:292
const Gecode::PropCond PC_BOOL_VAL
Propagate when a view becomes assigned (single value)
Definition: var-type.hpp:126
#define forceinline
Definition: config.hpp:192