edu.rice.cs.plt.collect
Class UnindexedRelation<T1,T2>

java.lang.Object
  java.util.AbstractCollection<E>
      java.util.AbstractSet<T>
          edu.rice.cs.plt.collect.AbstractPredicateSet<Pair<T1,T2>>
              edu.rice.cs.plt.collect.AbstractRelation<T1,T2>
                  edu.rice.cs.plt.collect.UnindexedRelation<T1,T2>

All Implemented Interfaces:

PredicateSet<Pair<T1,T2>>, Relation<T1,T2>, SizedIterable<Pair<T1,T2>>, Predicate<java.lang.Object>, Predicate2<T1,T2>, java.lang.Iterable<Pair<T1,T2>>, java.util.Collection<Pair<T1,T2>>, java.util.Set<Pair<T1,T2>>

public class UnindexedRelation<T1,T2>
extends AbstractRelation<T1,T2>

A mutable relation implemented by wrapping a set of pairs. The iteration order and performance characteristics of the relation match that of the underlying set. Lookup operations like #matchFirst() are not optimized with an index, and thus have poor performance. This class is useful when the relation is expected to be small, or when low allocation cost, a small memory footprint, and iteration order are more important than performance of index-related operations.

Nested Class Summary

Nested classes/interfaces inherited from class edu.rice.cs.plt.collect.AbstractRelation

AbstractRelation.InverseRelation

Constructor Summary

UnindexedRelation()
Create an UnindexedRelation wrapping a HashSet.

UnindexedRelation(Thunk<java.util.Set<Pair<T1,T2>>> setFactory)
Create an UnindexedRelation wrapping an instance of the provided set.

Method Summary

boolean	add(T1 first, T2 second) Add Pair.make(first, second) to the set.
void	clear()
boolean	contains(java.lang.Object obj) Test whether the set contains an object.
boolean	contains(T1 first, T2 second) Tests whether the given objects appear as a pair in this relation.
PredicateSet<T1>	firstSet() The set of firsts.
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.
java.util.Iterator<Pair<T1,T2>>	iterator()
static <T1,T2> UnindexedRelation<T1,T2>	makeHashBased() Make an UnindexedRelation wrapping a HashSet.
static <T1,T2> UnindexedRelation<T1,T2>	makeLinkedHashBased() Make an UnindexedRelation wrapping a LinkedHashSet.
static <T1 extends java.lang.Comparable<? super T1>,T2 extends java.lang.Comparable<? super T2>> UnindexedRelation<T1,T2>	makeTreeBased() Make an UnindexedRelation wrapping a TreeSet.
PredicateSet<T2>	matchFirst(T1 first) The set of seconds corresponding to a specific first.
PredicateSet<T1>	matchSecond(T2 second) The set of firsts corresponding to a specific second.
boolean	remove(T1 first, T2 second) Remove Pair.make(first, second) from the set.
PredicateSet<T2>	secondSet() The set of seconds.
int	size() Returns size(Integer.MAX_VALUE).

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

add, containsFirst, containsSecond, excludeFirsts, excludeSeconds, inverse, remove

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

size

Methods inherited from class java.util.AbstractSet

equals, hashCode, removeAll

Methods inherited from class java.util.AbstractCollection

addAll, containsAll, 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

addAll, containsAll, equals, hashCode, removeAll, retainAll, toArray, toArray

Methods inherited from interface edu.rice.cs.plt.iter.SizedIterable

size

Constructor Detail

UnindexedRelation

public UnindexedRelation()

Create an UnindexedRelation wrapping a HashSet.

UnindexedRelation

public UnindexedRelation(Thunk<java.util.Set<Pair<T1,T2>>> setFactory)

Create an UnindexedRelation wrapping an instance of the provided set.

Method Detail

isEmpty

public boolean isEmpty()

Description copied from class: AbstractPredicateSet

Returns size(1) == 0.

Specified by:

isEmpty in interface SizedIterable<Pair<T1,T2>>

Specified by:

isEmpty in interface java.util.Collection<Pair<T1,T2>>

Specified by:

isEmpty in interface java.util.Set<Pair<T1,T2>>

Overrides:

isEmpty in class AbstractPredicateSet<Pair<T1,T2>>

size

public int size()

Description copied from class: AbstractPredicateSet

Returns size(Integer.MAX_VALUE).

Specified by:

size in interface SizedIterable<Pair<T1,T2>>

Specified by:

size in interface java.util.Collection<Pair<T1,T2>>

Specified by:

size in interface java.util.Set<Pair<T1,T2>>

Overrides:

size in class AbstractPredicateSet<Pair<T1,T2>>

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<Pair<T1,T2>>

Specified by:

hasFixedSize in class AbstractRelation<T1,T2>

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<Pair<T1,T2>>

Specified by:

isInfinite in class AbstractRelation<T1,T2>

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<Pair<T1,T2>>

Specified by:

isStatic in class AbstractRelation<T1,T2>

contains

public boolean contains(T1 first,
                        T2 second)

Description copied from class: AbstractRelation

Tests whether the given objects appear as a pair in this relation. Not guaranteed to have types T1 and T2 because the Collection.contains(java.lang.Object) method allows arbitrary objects.

Specified by:

contains in interface Relation<T1,T2>

Specified by:

contains in interface Predicate2<T1,T2>

Specified by:

contains in class AbstractRelation<T1,T2>

contains

public boolean contains(java.lang.Object obj)

Description copied from class: AbstractPredicateSet

Test whether the set contains an object. Overridden here to force subclasses to provide an implementation. The default implementation (AbstractCollection.contains(java.lang.Object)) is a linear search, which is almost always unreasonable for a set.

Specified by:

contains in interface Relation<T1,T2>

Specified by:

contains in interface Predicate<java.lang.Object>

Specified by:

contains in interface java.util.Collection<Pair<T1,T2>>

Specified by:

contains in interface java.util.Set<Pair<T1,T2>>

Specified by:

contains in class AbstractRelation<T1,T2>

iterator

public java.util.Iterator<Pair<T1,T2>> iterator()

Specified by:

iterator in interface java.lang.Iterable<Pair<T1,T2>>

Specified by:

iterator in interface java.util.Collection<Pair<T1,T2>>

Specified by:

iterator in interface java.util.Set<Pair<T1,T2>>

Specified by:

iterator in class AbstractRelation<T1,T2>

add

public boolean add(T1 first,
                   T2 second)

Description copied from interface: Relation

Add Pair.make(first, second) to the set.

Specified by:

add in interface Relation<T1,T2>

Overrides:

add in class AbstractRelation<T1,T2>

remove

public boolean remove(T1 first,
                      T2 second)

Description copied from interface: Relation

Remove Pair.make(first, second) from the set.

Specified by:

remove in interface Relation<T1,T2>

Overrides:

remove in class AbstractRelation<T1,T2>

clear

public void clear()

Specified by:

clear in interface java.util.Collection<Pair<T1,T2>>

Specified by:

clear in interface java.util.Set<Pair<T1,T2>>

Overrides:

clear in class java.util.AbstractCollection<Pair<T1,T2>>

firstSet

public PredicateSet<T1> firstSet()

Description copied from interface: Relation

The set of firsts. Need not allow mutation, but must reflect subsequent changes.

Specified by:

firstSet in interface Relation<T1,T2>

Specified by:

firstSet in class AbstractRelation<T1,T2>

matchFirst

public PredicateSet<T2> matchFirst(T1 first)

Description copied from interface: Relation

The set of seconds corresponding to a specific first. Need not allow mutation, but must reflect subsequent changes.

Specified by:

matchFirst in interface Relation<T1,T2>

Specified by:

matchFirst in class AbstractRelation<T1,T2>

secondSet

public PredicateSet<T2> secondSet()

Description copied from interface: Relation

The set of seconds. Need not allow mutation, but must reflect subsequent changes.

Specified by:

secondSet in interface Relation<T1,T2>

Specified by:

secondSet in class AbstractRelation<T1,T2>

matchSecond

public PredicateSet<T1> matchSecond(T2 second)

Description copied from interface: Relation

The set of firsts corresponding to a specific second. Need not allow mutation, but must reflect subsequent changes.

Specified by:

matchSecond in interface Relation<T1,T2>

Specified by:

matchSecond in class AbstractRelation<T1,T2>

makeHashBased

public static <T1,T2> UnindexedRelation<T1,T2> makeHashBased()

Make an UnindexedRelation wrapping a HashSet.

makeLinkedHashBased

public static <T1,T2> UnindexedRelation<T1,T2> makeLinkedHashBased()

Make an UnindexedRelation wrapping a LinkedHashSet.

makeTreeBased

public static <T1 extends java.lang.Comparable<? super T1>,T2 extends java.lang.Comparable<? super T2>> UnindexedRelation<T1,T2> makeTreeBased()

Make an UnindexedRelation wrapping a TreeSet.