edu.rice.cs.plt.collect
Class IntersectionSet<E>

java.lang.Object
  java.util.AbstractCollection<E>
      java.util.AbstractSet<T>
          edu.rice.cs.plt.collect.AbstractPredicateSet<T>
              edu.rice.cs.plt.collect.FilteredSet<E>
                  edu.rice.cs.plt.collect.IntersectionSet<E>

All Implemented Interfaces:

PredicateSet<E>, SizedIterable<E>, Predicate<java.lang.Object>, Composite, java.io.Serializable, java.lang.Iterable<E>, java.util.Collection<E>, java.util.Set<E>

public class IntersectionSet<E>
extends FilteredSet<E>

The intersection of two sets, lazily constructed and updated dynamically. This improves on a general FilteredSet by taking advantage of the fact that the predicate used for filtering is also a set.

See Also:

Serialized Form

Field Summary

Fields inherited from class edu.rice.cs.plt.collect.FilteredSet

_pred, _set

Constructor Summary

IntersectionSet(java.util.Set<?> set1, java.util.Set<? extends E> set2)
To guarantee that the intersection is a set of E, only one of the arguments must be a set of Es.

Method Summary

boolean	hasFixedSize() true if this iterable is known to have a fixed size.
boolean	isEmpty() Returns size(1) == 0.
boolean	isInfinite() true if the iterable is known to have infinite size.
boolean	isStatic() true if this iterable is unchanging.

Methods inherited from class edu.rice.cs.plt.collect.FilteredSet

compositeHeight, compositeSize, contains, containsAll, iterator

Methods inherited from class edu.rice.cs.plt.collect.AbstractPredicateSet

size, size

Methods inherited from class java.util.AbstractSet

equals, hashCode, removeAll

Methods inherited from class java.util.AbstractCollection

add, addAll, clear, remove, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Set

add, addAll, clear, equals, hashCode, remove, removeAll, retainAll, toArray, toArray

Constructor Detail

IntersectionSet

public IntersectionSet(java.util.Set<?> set1,
                       java.util.Set<? extends E> set2)

To guarantee that the intersection is a set of E, only one of the arguments must be a set of Es. We arbitrarily choose set2. For best performance of FilteredSet.iterator(), AbstractPredicateSet.size(), and isEmpty(), set2 should be the smaller of the two sets (this is not handled automatically because calculating sizes may be expensive).

Method Detail

isInfinite

public boolean isInfinite()

Description copied from interface: SizedIterable

true if the iterable is known to have infinite size. If true, an iterator over the iterable in its current state will never return false from hasNext().

Specified by:

isInfinite in interface SizedIterable<E>

Overrides:

isInfinite in class FilteredSet<E>

hasFixedSize

public boolean hasFixedSize()

Description copied from interface: SizedIterable

true if this iterable is known to have a fixed size. This is the case if the iterable is immutable, or if changes can only replace values, not remove or add them. An infinite iterable may be fixed if it is guaranteed to never become finite.

Specified by:

hasFixedSize in interface SizedIterable<E>

Overrides:

hasFixedSize in class FilteredSet<E>

isStatic

public boolean isStatic()

Description copied from interface: SizedIterable

true if this iterable is unchanging. This implies that hasFixedSize() is true, and that iterator() will always return the same (either == or equal() and immutable) elements in the same order. ("Immutable" here means that equals() invocations are consistent over time -- if two objects are equal, they will never become inequal, and vice versa.)

Specified by:

isStatic in interface SizedIterable<E>

Overrides:

isStatic in class FilteredSet<E>

isEmpty

public boolean isEmpty()

Description copied from class: AbstractPredicateSet

Returns size(1) == 0.

Specified by:

isEmpty in interface SizedIterable<E>

Specified by:

isEmpty in interface java.util.Collection<E>

Specified by:

isEmpty in interface java.util.Set<E>

Overrides:

isEmpty in class FilteredSet<E>