com.yahoo.bard.webservice.util

Class Either<L,R>

java.lang.Object

com.yahoo.bard.webservice.util.Either<L,R>

Type Parameters:

L - The type of the Left value

R - The type of the Right value

public class Either<L,R>
extends Object

An Either is a bean that contains one of two possible values, referred to generically as Left or Right.

An Either is _not_ a pair. It does not contain two values. It only contains one value. However, the type of the value could either be the left type, or the right type.

A poor facsimile of the Either monad in Haskell that should make all Haskellers cry a little.

Method Summary

Modifier and Type	Method and Description
L	getLeft() Returns the Left value wrapped in this Either.
R	getRight() Returns the Right value wrapped in this Either.
boolean	isLeft() Returns whether or not this Either represents a Left value.
boolean	isRight() Returns whether or not this Either represents a Right value.
static <L,R> Either<L,R>	left(L left) Constructs an Either containing a left value.
static <L,R> Either<L,R>	right(R right) Constructs an Either containing a right value.

Methods inherited from class java.lang.Object

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

Method Detail

left

public static <L,R> Either<L,R> left(L left)

Constructs an Either containing a left value.

Type Parameters:

L - The type of the left value

R - The type of the right value

Parameters:

left - The left value to store in the either

Returns:

An Either wrapping the left value

right

public static <L,R> Either<L,R> right(R right)

Constructs an Either containing a right value.

Type Parameters:

L - The type of the left value

R - The type of the right value

Parameters:

right - The right value to store in the either

Returns:

An Either wrapping the right value

isLeft

public boolean isLeft()

Returns whether or not this Either represents a Left value.

Returns:

True if this Either is a Left value, false otherwise

getLeft

public L getLeft()

Returns the Left value wrapped in this Either.

Returns:

The Left value wrapped in this Either

Throws:

UnsupportedOperationException - If this Either wraps a Right value instead

isRight

public boolean isRight()

Returns whether or not this Either represents a Right value.

Returns:

True if this Either is a Right value, false otherwise

getRight

public R getRight()

Returns the Right value wrapped in this Either.

Returns:

The Right value wrapped in this Either

Throws:

UnsupportedOperationException - If this Either wraps a Left value instead