Package org.sosy_lab.java_smt.example.nqueens_user_propagator

Class NQueensConstraintPropagator

java.lang.Object

org.sosy_lab.java_smt.basicimpl.AbstractUserPropagator

org.sosy_lab.java_smt.example.nqueens_user_propagator.NQueensEnumeratingPropagator

org.sosy_lab.java_smt.example.nqueens_user_propagator.NQueensConstraintPropagator

All Implemented Interfaces:

UserPropagator

public class NQueensConstraintPropagator
extends NQueensEnumeratingPropagator

In addition to the enumeration done by NQueensEnumeratingPropagator, this propagator also enforces the queen placement constraints without explicit encoding.

Field Summary

Fields inherited from class org.sosy_lab.java_smt.example.nqueens_user_propagator.NQueensEnumeratingPropagator

currentModel, fixedCount, fixedVariables, modelSet

Constructor Summary

Constructors

Constructor	Description
NQueensConstraintPropagator(BooleanFormula[][] symbols)

Method Summary

Modifier and Type	Method	Description
void	onKnownValue(BooleanFormula var, boolean value)	This callback is invoked if the solver gets to know the value of a registered expression (UserPropagator.registerExpression(org.sosy_lab.java_smt.api.BooleanFormula)).

Methods inherited from class org.sosy_lab.java_smt.example.nqueens_user_propagator.NQueensEnumeratingPropagator

getNumOfSolutions, initializeWithBackend, onFinalCheck, onPop, onPush

Methods inherited from class org.sosy_lab.java_smt.basicimpl.AbstractUserPropagator

getBackend, onDecision, registerExpression

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NQueensConstraintPropagator

public NQueensConstraintPropagator(BooleanFormula[][] symbols)

Method Detail

onKnownValue

public void onKnownValue(BooleanFormula var,
                         boolean value)

Description copied from interface: UserPropagator

This callback is invoked if the solver gets to know the value of a registered expression (UserPropagator.registerExpression(org.sosy_lab.java_smt.api.BooleanFormula)). Within the callback, the user can raise conflicts via PropagatorBackend.propagateConflict(org.sosy_lab.java_smt.api.BooleanFormula[]), propagate consequences via PropagatorBackend.propagateConsequence(org.sosy_lab.java_smt.api.BooleanFormula[], org.sosy_lab.java_smt.api.BooleanFormula), or influence the solvers decision heuristics via PropagatorBackend.propagateNextDecision(org.sosy_lab.java_smt.api.BooleanFormula, java.util.Optional<java.lang.Boolean>).

The reported value is only known on the current and later push levels, but will get invalidated when backtracking.

Note: This callback is only invoked if the user propagator enabled it via PropagatorBackend.notifyOnKnownValue().

Specified by:

onKnownValue in interface UserPropagator

Overrides:

onKnownValue in class NQueensEnumeratingPropagator

Parameters:

var - The expressions whose value is known.

value - The value of the expression.