com.facebook.buck.util.types

Class Either<LEFT,RIGHT>

java.lang.Object

com.facebook.buck.util.types.Either<LEFT,RIGHT>

public abstract class Either<LEFT,RIGHT>
extends Object

A discriminated union of two parameters that holds a value of either the LEFT or RIGHT type.

Method Summary

Modifier and Type	Method and Description
abstract LEFT	getLeft() Returns the left value.
abstract Optional<LEFT>	getLeftOption() Left value or empty otherwise.
abstract RIGHT	getRight() Returns the right value.
abstract Optional<RIGHT>	getRightOption() Right value or empty otherwise.
abstract boolean	isLeft() Returns whether the instance holds a left value.
abstract boolean	isRight() Returns whether the instance holds a right value.
static <LEFT,RIGHT> Either<LEFT,RIGHT>	ofLeft(LEFT value)
static <LEFT,RIGHT> Either<LEFT,RIGHT>	ofRight(RIGHT value)
abstract <X> X	transform(java.util.function.Function<LEFT,X> lhsTransformer, java.util.function.Function<RIGHT,X> rhsTransformer) Apply a function based on whether the instance holds a left or right value.

Methods inherited from class java.lang.Object

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

Method Detail

isLeft

public abstract boolean isLeft()

Returns whether the instance holds a left value.

isRight

public abstract boolean isRight()

Returns whether the instance holds a right value.

getLeft

public abstract LEFT getLeft()

Returns the left value.

Throws:

IllegalStateException - if this instance does not hold a left value.

getRight

public abstract RIGHT getRight()

Returns the right value.

Throws:

IllegalStateException - if this instance does not hold a right value.

getLeftOption

public abstract Optional<LEFT> getLeftOption()

Left value or empty otherwise.

getRightOption

public abstract Optional<RIGHT> getRightOption()

Right value or empty otherwise.

transform

public abstract <X> X transform(java.util.function.Function<LEFT,X> lhsTransformer,
                                java.util.function.Function<RIGHT,X> rhsTransformer)

Apply a function based on whether the instance holds a left or right value.

ofLeft

public static <LEFT,RIGHT> Either<LEFT,RIGHT> ofLeft(LEFT value)

ofRight

public static <LEFT,RIGHT> Either<LEFT,RIGHT> ofRight(RIGHT value)