org.wandora.utils

Class Tuples

java.lang.Object

org.wandora.utils.Tuples

public class Tuples
extends java.lang.Object

A Tuple library to make it easy to return two or more values from a method. Requires Java 1.5. To use do something like

 import static com.gripstudios.utils.Tuples.*;
 ...
      T2<Integer,String> foo(int x,int y){
          return t2(y,new String(x));
      }
 ...
 

Note that this is typesafe where returning an Object[] is not. Note that it is always a good idea to consider making a real class for the return value. Especially if you need a tuple of more than 4 values (only T2,T3 and T4 are provided in this class) you probably should make it a real class.

The Tuple classes override equals to check the equality for each element of the tuples respectively. hashCode is also overridden so Tuples can safely be used in hashMaps. You may put nulls in tuples.

Note that tuples are immutable, you can't change the elements in them. Instead create a new tuple, for example

  T2<String,Integer> a=t2("aaa",2);
  ...
  a=t2(a.e1,a.e2+1);
 

Note that t2("",new Vector()) will create a T2 rather than T2. If you want the second element to be a Collection you will have to cast the parameter: t2(String,(Collection)new Vector()) or t2(String,(Collection<Integer>)new Vector()) to be more specific.

Author:

olli

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Tuples.T2<E1,E2>
static class	Tuples.T3<E1,E2,E3>
static class	Tuples.T4<E1,E2,E3,E4>
static class	Tuples.T5<E1,E2,E3,E4,E5>
static class	Tuples.T6<E1,E2,E3,E4,E5,E6>

Constructor Summary

Constructors

Modifier	Constructor and Description
private	Tuples()

Method Summary

Modifier and Type	Method and Description
private static boolean	e(java.lang.Object o1, java.lang.Object o2)
static <E1,E2> Tuples.T2<E1,E2>	t2(E1 e1, E2 e2)
static <E1,E2,E3> Tuples.T3<E1,E2,E3>	t3(E1 e1, E2 e2, E3 e3)
static <E1,E2,E3,E4> Tuples.T4<E1,E2,E3,E4>	t4(E1 e1, E2 e2, E3 e3, E4 e4)
static <E1,E2,E3,E4,E5> Tuples.T5<E1,E2,E3,E4,E5>	t5(E1 e1, E2 e2, E3 e3, E4 e4, E5 e5)
static <E1,E2,E3,E4,E5,E6> Tuples.T6<E1,E2,E3,E4,E5,E6>	t6(E1 e1, E2 e2, E3 e3, E4 e4, E5 e5, E6 e6)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Tuples

private Tuples()

Method Detail

e

private static boolean e(java.lang.Object o1,
                         java.lang.Object o2)

t2

public static <E1,E2> Tuples.T2<E1,E2> t2(E1 e1,
                                          E2 e2)

t3

public static <E1,E2,E3> Tuples.T3<E1,E2,E3> t3(E1 e1,
                                                E2 e2,
                                                E3 e3)

t4

public static <E1,E2,E3,E4> Tuples.T4<E1,E2,E3,E4> t4(E1 e1,
                                                      E2 e2,
                                                      E3 e3,
                                                      E4 e4)

t5

public static <E1,E2,E3,E4,E5> Tuples.T5<E1,E2,E3,E4,E5> t5(E1 e1,
                                                            E2 e2,
                                                            E3 e3,
                                                            E4 e4,
                                                            E5 e5)

t6

public static <E1,E2,E3,E4,E5,E6> Tuples.T6<E1,E2,E3,E4,E5,E6> t6(E1 e1,
                                                                  E2 e2,
                                                                  E3 e3,
                                                                  E4 e4,
                                                                  E5 e5,
                                                                  E6 e6)