net.sourceforge.czt.animation.eval.flatpred

Class FlatOr

java.lang.Object

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

net.sourceforge.czt.animation.eval.flatpred.FlatOr

public class FlatOr
extends FlatPred

FlatOr(p, q) implements p \lor q. It returns all the solutions from p, followed by all the solutions from q. The two FlatPreds or FlatPredLists p and q must have identical modes.

Author:

marku

Field Summary

Fields

Modifier and Type	Field and Description
protected Bounds	leftBounds_ Bounds information for the left_ predicate.
protected Set<net.sourceforge.czt.z.ast.ZName>	outputs_ The variables that are created by *both* sides.
protected Bounds	rightBounds_ Bounds information for the right_ predicate.

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

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

Constructor Summary

Constructors

Constructor and Description
FlatOr(FlatPredList left, FlatPredList right) Creates a new instance of FlatOr.

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 env0) Choose the mode that this predicate could use in this environment.
boolean	inferBounds(Bounds bnds) Bounds information can only flow into the disjuncts at the moment.
boolean	nextEvaluation() Generates the next solution that satisfies this predicate.
void	setMode(Mode mode) Set the mode that will be used to evaluate this list.
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

Methods inherited from class java.lang.Object

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

Field Detail

leftBounds_

protected Bounds leftBounds_

Bounds information for the left_ predicate.

rightBounds_

protected Bounds rightBounds_

Bounds information for the right_ predicate.

outputs_

protected Set<net.sourceforge.czt.z.ast.ZName> outputs_

The variables that are created by *both* sides. (This is known only after setMode).

Constructor Detail

FlatOr

public FlatOr(FlatPredList left,
              FlatPredList right)

Creates a new instance of FlatOr. The left and right sides can have different sets of free variables (as well as different bound variables, obviously). However, chooseMode() will succeed only when both sides have the same set of output variables, so the differences in the freevar sets must be only in the input variables.

Method Detail

inferBounds

public boolean inferBounds(Bounds bnds)

Bounds information can only flow into the disjuncts at the moment. TODO: Allowing it to flow out requires taking the disjunction of the bounds of the two disjuncts.

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 env0)

Description copied from class: FlatPred

Choose the mode that this predicate could use in this environment. The result is null if no evaluation is possible. Otherwise, the resulting Mode object contains an updated environment (with any output variables added), plus various estimates about how expensive this predicate will be to execute.

Specified by:

chooseMode in class FlatPred

Returns:

The Mode object, with statistics and an updated environment.

setMode

public void setMode(Mode mode)

Set the mode that will be used to evaluate this list.

Overrides:

setMode in class FlatPred

Parameters:

mode - Must be one of the modes returned previously by chooseMode.

startEvaluation

public void startEvaluation()

Overrides:

startEvaluation in class FlatPred

nextEvaluation

public boolean nextEvaluation()

Description copied from class: FlatPred

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

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