net.sourceforge.czt.animation.eval.flatpred

Class FlatLessThanEquals

java.lang.Object

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

net.sourceforge.czt.animation.eval.flatpred.FlatLessThanEquals

public class FlatLessThanEquals
extends FlatPred

FlatPlus implements the a <= b predicate.

Field Summary

Fields

Modifier and Type	Field and Description
protected BigInteger	next

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

args_, evalMode_, freeVars_, INDENT, LOG, printer_, solutionsReturned_

Constructor Summary

Constructors

Constructor and Description
FlatLessThanEquals(net.sourceforge.czt.z.ast.ZName a, net.sourceforge.czt.z.ast.ZName b)

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.
Mode	chooseMode(Envir env) Chooses the mode in which the predicate can be evaluated.
boolean	inferBounds(Bounds bnds) Infer bounds for any integer variables.
boolean	nextEvaluation() Does the actual evaluation
void	startEvaluation()
String	toString() A default implementation of toString.

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

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

Methods inherited from class java.lang.Object

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

Field Detail

next

protected BigInteger next

Constructor Detail

FlatLessThanEquals

public FlatLessThanEquals(net.sourceforge.czt.z.ast.ZName a,
                          net.sourceforge.czt.z.ast.ZName b)

Method Detail

inferBounds

public boolean inferBounds(Bounds bnds)

Description copied from class: FlatPred

Infer bounds for any integer variables. This analyzes the possible range of values of each integer variable used by this FlatPred, and reduces the range of values if possible. This is a kind of static analysis commonly used in constraint solvers (bounds consistency). For example, if y already has the range 10..20, then the FlatPred x < y would set the maximum value of x to 19.

Overrides:

inferBounds in class FlatPred

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.

chooseMode

public Mode chooseMode(Envir env)

Chooses the mode in which the predicate can be evaluated.

Specified by:

chooseMode in class FlatPred

Returns:

The Mode object, with statistics and an updated environment.

startEvaluation

public void startEvaluation()

Overrides:

startEvaluation in class FlatPred

nextEvaluation

public boolean nextEvaluation()

Does the actual evaluation

Specified by:

nextEvaluation in class FlatPred

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 FlatPred

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 FlatPred