se.chalmers.cs.gf.util
Class Pair<A,B>

java.lang.Object
  se.chalmers.cs.gf.util.Pair<A,B>

Type Parameters:

A - The type of the first value.

B - The type of the second value.

All Implemented Interfaces:

java.lang.Comparable<Pair<A,B>>

Direct Known Subclasses:

MapEntryPair

public class Pair<A,B>
extends java.lang.Object
implements java.lang.Comparable<Pair<A,B>>

An immutable 2-tuple. Based on code from Higher-Order Java.

Field Summary

A	fst The first component.
B	snd The second component.

Constructor Summary

Pair(A fst, B snd)
Creates a new pair.

Method Summary

int	compareTo(Pair<A,B> p) FIXME: Fails if the element types are not comparable.
boolean	equals(java.lang.Object o) Compares this pair to another object for equality.
int	hashCode() Returns a hash code for this pair.
static <A,B> Pair<A,B>	pair(A a, B b) Construct a pair.
java.lang.Object[]	toArray() Gets an array representation of this pair.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

fst

public final A fst

The first component.

snd

public final B snd

The second component.

Constructor Detail

Pair

public Pair(A fst,
            B snd)

Creates a new pair.

Parameters:

fst - The first component.

snd - The second component.

Method Detail

equals

public boolean equals(java.lang.Object o)

Compares this pair to another object for equality.

Overrides:

equals in class java.lang.Object

Parameters:

o - The object to compare this pair with.

Returns:

true iff o is not null and o is a Pair and the components of this and o are pairwise equal or both null.

hashCode

public int hashCode()

Returns a hash code for this pair. The hash code is calculated from the hash codes of the components.

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

compareTo

public int compareTo(Pair<A,B> p)

FIXME: Fails if the element types are not comparable.

Specified by:

compareTo in interface java.lang.Comparable<Pair<A,B>>

toArray

public java.lang.Object[] toArray()

Gets an array representation of this pair.

Returns:

A 2-element array containing the elements of this pair in order.

pair

public static <A,B> Pair<A,B> pair(A a,
                                   B b)

Construct a pair. Convenience method to allow type inference and