com.microsoft.z3.Goal Maven / Gradle / Ivy
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/**
Copyright (c) 2012-2014 Microsoft Corporation
Module Name:
Goal.java
Abstract:
Author:
@author Christoph Wintersteiger (cwinter) 2012-03-15
Notes:
**/
package com.microsoft.z3;
import com.microsoft.z3.enumerations.Z3_goal_prec;
import java.lang.ref.ReferenceQueue;
/**
* A goal (aka problem). A goal is essentially a set of formulas, that can be
* solved and/or transformed using tactics and solvers.
**/
public class Goal extends Z3Object {
/**
* The precision of the goal.
* Remarks: Goals can be transformed using over
* and under approximations. An under approximation is applied when the
* objective is to find a model for a given goal. An over approximation is
* applied when the objective is to find a proof for a given goal.
*
**/
public Z3_goal_prec getPrecision()
{
return Z3_goal_prec.fromInt(Native.goalPrecision(getContext().nCtx(),
getNativeObject()));
}
/**
* Indicates whether the goal is precise.
**/
public boolean isPrecise()
{
return getPrecision() == Z3_goal_prec.Z3_GOAL_PRECISE;
}
/**
* Indicates whether the goal is an under-approximation.
**/
public boolean isUnderApproximation()
{
return getPrecision() == Z3_goal_prec.Z3_GOAL_UNDER;
}
/**
* Indicates whether the goal is an over-approximation.
**/
public boolean isOverApproximation()
{
return getPrecision() == Z3_goal_prec.Z3_GOAL_OVER;
}
/**
* Indicates whether the goal is garbage (i.e., the product of over- and
* under-approximations).
**/
public boolean isGarbage()
{
return getPrecision() == Z3_goal_prec.Z3_GOAL_UNDER_OVER;
}
/**
* Adds the {@code constraints} to the given goal.
*
* @throws Z3Exception
**/
@SafeVarargs
public final void add(Expr... constraints)
{
getContext().checkContextMatch(constraints);
for (Expr c : constraints)
{
Native.goalAssert(getContext().nCtx(), getNativeObject(),
c.getNativeObject());
}
}
/**
* Indicates whether the goal contains `false'.
**/
public boolean inconsistent()
{
return Native.goalInconsistent(getContext().nCtx(), getNativeObject());
}
/**
* The depth of the goal.
* Remarks: This tracks how many transformations
* were applied to it.
**/
public int getDepth()
{
return Native.goalDepth(getContext().nCtx(), getNativeObject());
}
/**
* Erases all formulas from the given goal.
**/
public void reset()
{
Native.goalReset(getContext().nCtx(), getNativeObject());
}
/**
* The number of formulas in the goal.
**/
public int size()
{
return Native.goalSize(getContext().nCtx(), getNativeObject());
}
/**
* The formulas in the goal.
*
* @throws Z3Exception
**/
public BoolExpr[] getFormulas()
{
int n = size();
BoolExpr[] res = new BoolExpr[n];
for (int i = 0; i < n; i++)
res[i] = (BoolExpr) Expr.create(getContext(), Native.goalFormula(getContext().nCtx(), getNativeObject(), i));
return res;
}
/**
* The number of formulas, subformulas and terms in the goal.
**/
public int getNumExprs()
{
return Native.goalNumExprs(getContext().nCtx(), getNativeObject());
}
/**
* Indicates whether the goal is empty, and it is precise or the product of
* an under approximation.
**/
public boolean isDecidedSat()
{
return Native.goalIsDecidedSat(getContext().nCtx(), getNativeObject());
}
/**
* Indicates whether the goal contains `false', and it is precise or the
* product of an over approximation.
**/
public boolean isDecidedUnsat()
{
return Native
.goalIsDecidedUnsat(getContext().nCtx(), getNativeObject());
}
/**
* Translates (copies) the Goal to the target Context {@code ctx}.
*
* @throws Z3Exception
**/
public Goal translate(Context ctx)
{
return new Goal(ctx, Native.goalTranslate(getContext().nCtx(),
getNativeObject(), ctx.nCtx()));
}
/**
* Simplifies the goal.
* Remarks: Essentially invokes the `simplify' tactic
* on the goal.
**/
public Goal simplify()
{
Tactic t = getContext().mkTactic("simplify");
ApplyResult res = t.apply(this);
if (res.getNumSubgoals() == 0)
throw new Z3Exception("No subgoals");
else
return res.getSubgoals()[0];
}
/**
* Simplifies the goal.
* Remarks: Essentially invokes the `simplify' tactic
* on the goal.
**/
public Goal simplify(Params p)
{
Tactic t = getContext().mkTactic("simplify");
ApplyResult res = t.apply(this, p);
if (res.getNumSubgoals() == 0)
throw new Z3Exception("No subgoals");
else
return res.getSubgoals()[0];
}
/**
* Goal to string conversion.
*
* @return A string representation of the Goal.
**/
public String toString() {
return Native.goalToString(getContext().nCtx(), getNativeObject());
}
/**
* Goal to BoolExpr conversion.
*
* Returns a string representation of the Goal.
**/
public BoolExpr AsBoolExpr() {
int n = size();
if (n == 0) {
return getContext().mkTrue();
} else if (n == 1) {
return getFormulas()[0];
} else {
return getContext().mkAnd(getFormulas());
}
}
Goal(Context ctx, long obj)
{
super(ctx, obj);
}
Goal(Context ctx, boolean models, boolean unsatCores, boolean proofs) {
super(ctx, Native.mkGoal(ctx.nCtx(), (models),
(unsatCores), (proofs)));
}
/**
* Convert a model for the goal into a model of the
* original goal from which this goal was derived.
*
* @return A model for {@code g}
* @throws Z3Exception
**/
public Model convertModel(Model m)
{
return new Model(getContext(),
Native.goalConvertModel(getContext().nCtx(), getNativeObject(), m.getNativeObject()));
}
@Override
void incRef() {
Native.goalIncRef(getContext().nCtx(), getNativeObject());
}
@Override
void addToReferenceQueue() {
getContext().getReferenceQueue().storeReference(this, GoalRef::new);
}
private static class GoalRef extends Z3ReferenceQueue.Reference {
private GoalRef(Goal referent, ReferenceQueue q) {
super(referent, q);
}
@Override
void decRef(Context ctx, long z3Obj) {
Native.goalDecRef(ctx.nCtx(), z3Obj);
}
}
}