org.organicdesign.fp.tuple

Class Tuple2<A,B>

java.lang.Object

org.organicdesign.fp.tuple.Tuple2<A,B>

All Implemented Interfaces:

Serializable, Map.Entry<A,B>, UnmodMap.UnEntry<A,B>

public class Tuple2<A,B>
extends Object
implements Map.Entry<A,B>, UnmodMap.UnEntry<A,B>, Serializable

Holds 2 items of potentially different types, and implements Map.Entry (and UnmodMap.UnEntry (there is no ImMap.ImEntry)). Designed to let you easily create immutable subclasses (to give your data structures meaningful names) with correct equals(), hashCode(), and toString() methods.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.organicdesign.fp.collections.UnmodMap.UnEntry

UnmodMap.UnEntry.EntryToUnEntryIter<K,V>, UnmodMap.UnEntry.EntryToUnEntrySortedIter<K,V>, UnmodMap.UnEntry.UnmodKeyIter<K,V>, UnmodMap.UnEntry.UnmodSortedKeyIter<K,V>, UnmodMap.UnEntry.UnmodSortedValIter<K,V>, UnmodMap.UnEntry.UnmodValIter<K,V>

Field Summary

Fields

Modifier and Type	Field and Description
protected A	_1
protected B	_2

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Tuple2(A a, B b) Constructor is protected (not public) for easy inheritance.

Method Summary

Modifier and Type	Method and Description
A	_1() Returns the 1st field
B	_2() Returns the 2nd field
boolean	equals(Object other)
A	getKey() Returns the first field of the tuple.
B	getValue() Returns the second field of the tuple.
int	hashCode()
static <A,B> Tuple2<A,B>	of(A a, B b) Public static factory method
static <K,V> Tuple2<K,V>	of(Map.Entry<K,V> entry) Map.Entry factory method
B	setValue(B value) Deprecated.
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.organicdesign.fp.collections.UnmodMap.UnEntry

entryIterToUnEntrySortedUnIter, entryIterToUnEntryUnIter

Methods inherited from interface java.util.Map.Entry

comparingByKey, comparingByKey, comparingByValue, comparingByValue

Field Detail

_1

protected final A _1

_2

protected final B _2

Constructor Detail

Tuple2

protected Tuple2(A a,
                 B b)

Constructor is protected (not public) for easy inheritance. Josh Bloch's "Item 1" says public static factory methods are better than constructors because they have names, they can return an existing object instead of a new one, and they can return a sub-type. Therefore, you have more flexibility with a static factory as part of your public API then with a public constructor.

Method Detail

of

public static <A,B> Tuple2<A,B> of(A a,
                                   B b)

Public static factory method

of

public static <K,V> Tuple2<K,V> of(Map.Entry<K,V> entry)

Map.Entry factory method

_1

public A _1()

Returns the 1st field

_2

public B _2()

Returns the 2nd field

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object other)

Specified by:

equals in interface Map.Entry<A,B>

Overrides:

equals in class Object

hashCode

public int hashCode()

Specified by:

hashCode in interface Map.Entry<A,B>

Overrides:

hashCode in class Object

getKey

public A getKey()

Returns the first field of the tuple. To implement Map.Entry.

Specified by:

getKey in interface Map.Entry<A,B>

getValue

public B getValue()

Returns the second field of the tuple. To implement Map.Entry.

Specified by:

getValue in interface Map.Entry<A,B>

setValue

@Deprecated
public B setValue(B value)

Deprecated.

This method is required to implement Map.Entry, but calling it only issues an exception

Specified by:

setValue in interface Map.Entry<A,B>

Specified by:

setValue in interface UnmodMap.UnEntry<A,B>