sdd

Class VtreeLeaf

java.lang.Object

buffer.CanonicalWatched

sdd.Vtree

sdd.VtreeLeaf

public final class VtreeLeaf
extends Vtree

A VtreeLeaf, i.e., a (vtree) leaf, is a tree that contains a single variable. To date, there may be two equals VtreeLeaf that are not equal by ==. One might therefore want to be careful and avoid an explosion of the number of equivalent instances of VtreeLeaf (cf. the implementation of VtreeNode for instance).

Method Summary

Methods

Modifier and Type	Method and Description
boolean	addVariables(java.util.Set<Variable> s) Adds the variables in this vtree to the specified set.
boolean	contains(Vtree vt) Indicates whether this vtree contains the specified vtree.
static VtreeLeaf	create(Variable var) Returns the vtree leaf associated with the specified variable.
boolean	equivalent(java.lang.Object o) Indicates whether the specified object is equivalent to this object.
boolean	findPathTo(Vtree vt, java.util.List<VtreeNode> path) Stores in the specified list the ``path'' from this vtree to the specified vtree (excluded).
protected java.util.Map<java.lang.Object,VtreeLeaf>	getBuffer() Returns the buffer that is used to decide the canonical objects.
int	getDepth() Returns the depth of this vtree.
Variable	getVariable() Returns the (single) variable associated with this vtree.
java.util.Set<Variable>	getVariables() Returns the collection of variables that decorate the leaves of this vtree.
int	hashCode()
boolean	isLeaf() Indicates whether this vtree is a leaf.
java.lang.String	toString()

Methods inherited from class buffer.CanonicalWatched

destroy, equals, getCanonical, print, unwatch, unwatchAll, verifyValidity, watch

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

create

public static VtreeLeaf create(Variable var)

Returns the vtree leaf associated with the specified variable.

Parameters:

var - the variable whose vtree is returned.

Returns:

the vtree associated with var.

hashCode

public int hashCode()

Specified by:

hashCode in class CanonicalWatched

equivalent

public boolean equivalent(java.lang.Object o)

Description copied from class: CanonicalWatched

Indicates whether the specified object is equivalent to this object. There should not be two equivalent objects, so this method is used at the creation of this type of object to verify whether the object create is truly original.

Specified by:

equivalent in class CanonicalWatched

Parameters:

o - the object compared to this object.

Returns:

true if obj is equivalent to this.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getVariable

public Variable getVariable()

Returns the (single) variable associated with this vtree.

Returns:

the variable that decorates this leaf.

getVariables

public java.util.Set<Variable> getVariables()

Description copied from class: Vtree

Returns the collection of variables that decorate the leaves of this vtree. Incidentally, this method also tests whether this vtree is correct, i.e., whether a variable appears twice in the tree.

Specified by:

getVariables in class Vtree

Returns:

the variables that this vtree is defined on.

isLeaf

public boolean isLeaf()

Description copied from class: Vtree

Indicates whether this vtree is a leaf.

Specified by:

isLeaf in class Vtree

Returns:

true if this vtree is a VtreeLeaf, false is this vtree is a VtreeNode.

addVariables

public boolean addVariables(java.util.Set<Variable> s)

Description copied from class: Vtree

Adds the variables in this vtree to the specified set.

Specified by:

addVariables in class Vtree

Parameters:

s - the set where the variables in this vtree should be inserted.

Returns:

true if all variables could be inserted, false if one of the variables of this vtree is inserted twice or was already in s.

getBuffer

protected java.util.Map<java.lang.Object,VtreeLeaf> getBuffer()

Description copied from class: CanonicalWatched

Returns the buffer that is used to decide the canonical objects.

Specified by:

getBuffer in class CanonicalWatched

Returns:

a map that contains the canonical objects.

getDepth

public int getDepth()

Description copied from class: Vtree

Returns the depth of this vtree. The depth is defined as the maximal distance between the root of this vtree and one of its leaves. The depth provides some insight about the content of the tree (whether it's worth checking something in its subtree for instance).

Specified by:

getDepth in class Vtree

Returns:

the depth of this vtree.

contains

public boolean contains(Vtree vt)

Description copied from class: Vtree

Indicates whether this vtree contains the specified vtree.

Specified by:

contains in class Vtree

Parameters:

vt - the vtree that is looked for.

Returns:

true if vt is part of this.

findPathTo

public boolean findPathTo(Vtree vt,
                 java.util.List<VtreeNode> path)

Description copied from class: Vtree

Stores in the specified list the ``path'' from this vtree to the specified vtree (excluded). A path is sequence of vtrees that are children (the left of the right element) of the next element in the sequence.

Specified by:

findPathTo in class Vtree

Parameters:

vt - the vtree to which a path is requested.

path - the list where the path is recorded.

Returns:

true if a path is found.