net.sourceforge.czt.animation.eval.flatpred

Class FlatExists

java.lang.Object

net.sourceforge.czt.animation.eval.flatpred.FlatPred

net.sourceforge.czt.animation.eval.flatpred.FlatForall

net.sourceforge.czt.animation.eval.flatpred.FlatExists

public class FlatExists
extends FlatForall

This implements the exists quantifier. It overrides the forall evaluation algorithm.

Field Summary

Fields

Modifier and Type	Field and Description
protected Bounds	bounds_

Fields inherited from class net.sourceforge.czt.animation.eval.flatpred.FlatForall

body_, bodyBounds_, bodyMode_, LOG, schBounds_, schMode_, schText_

Fields inherited from class net.sourceforge.czt.animation.eval.flatpred.FlatPred

args_, evalMode_, freeVars_, INDENT, printer_, solutionsReturned_

Constructor Summary

Constructors

Constructor and Description
FlatExists(FlatPredList sch, FlatPredList body)

Method Summary

Modifier and Type	Method and Description
<R> R	accept(net.sourceforge.czt.util.Visitor<R> visitor) Calls visitor.visitPred (preferably) or visitor.visitTerm.
boolean	inferBounds(Bounds bnds) This allows bounds information to flow into the Exists but not out.
boolean	nextEvaluation() Generates the next solution that satisfies this predicate.
String	toString() A default implementation of toString.

Methods inherited from class net.sourceforge.czt.animation.eval.flatpred.FlatForall

chooseMode, freeVars, setMode

Methods inherited from class net.sourceforge.czt.animation.eval.flatpred.FlatPred

getArgs, getEnvir, getLastArg, getMode, indent, modeAllDefined, modeCollection, modeFunction, modeOneOutput, printArg, printBinOp, printLastArg, printName, printQuant, startEvaluation

Methods inherited from class java.lang.Object

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

Field Detail

bounds_

protected Bounds bounds_

Constructor Detail

FlatExists

public FlatExists(FlatPredList sch,
                  FlatPredList body)

Method Detail

inferBounds

public boolean inferBounds(Bounds bnds)

This allows bounds information to flow into the Exists but not out. Within the Exists, bound information can flow in both directions between the bound variable constraints and the body of the Exists.

Overrides:

inferBounds in class FlatForall

Parameters:

bnds - The database of lower and upper bounds for integer variables.

Returns:

true iff the bnds database has been changed.

The default implementation infers nothing and returns false.

nextEvaluation

public boolean nextEvaluation()

Description copied from class: FlatPred

Generates the next solution that satisfies this predicate. This must only be called after startEvaluation().

Overrides:

nextEvaluation in class FlatForall

Returns:

true iff another solution has been found.

toString

public String toString()

Description copied from class: FlatPred

A default implementation of toString. This returns "FlatXXX(args[0], args[1], ...)".

Overrides:

toString in class FlatForall

accept

public <R> R accept(net.sourceforge.czt.util.Visitor<R> visitor)

Description copied from class: FlatPred

Calls visitor.visitPred (preferably) or visitor.visitTerm. Subclasses that correspond to particular kinds of Pred should override this to call more specific visitXXX methods (and should call super to handle the remaining cases).

Overrides:

accept in class FlatForall