javafixes.object

Class Either<L,R>

java.lang.Object

javafixes.object.DataObject

javafixes.object.Either<L,R>

Type Parameters:

L - the Left Either type

R - the Right Either type

All Implemented Interfaces:

Value<java.lang.Object>

Direct Known Subclasses:

Either.Left, Either.Right

public abstract class Either<L,R>
extends DataObject
implements Value<java.lang.Object>

Either can wrap value of one of 2 types defined as Left or Right. This is an unbiased implementation where both left and right side have the same methods and neither one is preferred.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Either.Left<L,R>
static class	Either.Right<L,R>

Method Summary

Modifier and Type	Method and Description
abstract <T> T	fold(java.util.function.Function<L,T> foldLeft, java.util.function.Function<R,T> foldRight) Transforms a value and returns it
abstract L	getLeft() Returns wrapped value in case the Either is of type Left.
abstract <T extends java.lang.Throwable> L	getLeftOrThrow(java.util.function.Supplier<? extends T> exceptionSupplier) Returns wrapped value in case the Either is of type Left.
abstract R	getRight() Returns wrapped value in case the Either is of type Right.
abstract <T extends java.lang.Throwable> R	getRightOrThrow(java.util.function.Supplier<? extends T> exceptionSupplier) Returns wrapped value in case the Either is of type Right.
abstract <TL extends java.lang.Throwable,TR extends java.lang.Throwable> Either<L,R>	handle(ValueHandler<? super L,? extends TL> leftValueHandler, ValueHandler<? super R,? extends TR> rightValueHandler) Executes provided leftValueHandler if value is defined as Left Either.
abstract <T extends java.lang.Throwable> Either<L,R>	handleLeft(ValueHandler<? super L,? extends T> leftValueHandler) Executes provided leftValueHandler if value is defined as Left Either.
abstract <T extends java.lang.Throwable> Either<L,R>	handleRight(ValueHandler<? super R,? extends T> rightValueHandler) Executes provided rightValueHandler if value is defined as Right Either.
abstract <T extends java.lang.Throwable> Either<L,R>	ifLeftThrow(java.util.function.Function<L,? extends T> exceptionSupplier) Throws Exception provided via exceptionSupplier if value is defined as Left Either.
abstract <T extends java.lang.Throwable> Either<L,R>	ifRightThrow(java.util.function.Function<R,? extends T> exceptionSupplier) Throws Exception provided via exceptionSupplier if value is defined as Right Either.
abstract boolean	isLeft() Returns true if value is wrapped into a Left Either
abstract boolean	isRight() Returns true if value is wrapped into a Right Either
static <L,R> Either<L,R>	left(L value) Generates Either of type Left wrapping the provided value
abstract <L2,R2> Either<L2,R2>	map(java.util.function.Function<L,L2> leftValueMapper, java.util.function.Function<R,R2> rightValueMapper) Applies provided leftValueMapper to transform wrapped value if value is defined as Left Either.
abstract <L2> Either<L2,R>	mapLeft(java.util.function.Function<L,L2> leftValueMapper) Applies provided leftValueMapper to transform wrapped value if value is defined as Left Either.
abstract <R2> Either<L,R2>	mapRight(java.util.function.Function<R,R2> rightValueMapper) Applies provided rightValueMapper to transform wrapped value if value is defined as Right Either.
static <L,R> Either<L,R>	right(R value) Generates Either of type Right wrapping the provided value
abstract Either<R,L>	swap() Swaps left and right value of an Either
abstract java.lang.Object	value() Returns left value if of type Either.Left or right value if of type Either.Right

Methods inherited from class javafixes.object.DataObject

equals, hashCode, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface javafixes.object.Value

getValue

Method Detail

right

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

Generates Either of type Right wrapping the provided value

Type Parameters:

L - generic type of left side

R - generic type of right side

Parameters:

value - value to wrap

Returns:

Right Either wrapping provided value

left

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

Generates Either of type Left wrapping the provided value

Type Parameters:

L - generic type of left side

R - generic type of right side

Parameters:

value - value to wrap

Returns:

Left Either wrapping provided value

swap

public abstract Either<R,L> swap()

Swaps left and right value of an Either

Returns:

Either with swapped left and right values

isLeft

public abstract boolean isLeft()

Returns true if value is wrapped into a Left Either

Returns:

true if is Left Either

isRight

public abstract boolean isRight()

Returns true if value is wrapped into a Right Either

Returns:

true if is Right Either

getLeft

public abstract L getLeft()
                   throws java.util.NoSuchElementException

Returns wrapped value in case the Either is of type Left. Throws a NoSuchElementException in case the Either is of type Right.

Returns:

value in case the Either is of type Left

Throws:

java.util.NoSuchElementException - in case the Either is of type Right

getRight

public abstract R getRight()
                    throws java.util.NoSuchElementException

Returns wrapped value in case the Either is of type Right. Throws a NoSuchElementException in case the Either is of type Left.

Returns:

value in case the Either is of type Right

Throws:

java.util.NoSuchElementException - in case the Either is of type Left

getLeftOrThrow

public abstract <T extends java.lang.Throwable> L getLeftOrThrow(java.util.function.Supplier<? extends T> exceptionSupplier)
                                                          throws T extends java.lang.Throwable

Returns wrapped value in case the Either is of type Left. Throws Exception provided via exceptionSupplier if value is defined as Right Either.

Type Parameters:

T - type of Exception that will be provided by exceptionSupplier

Parameters:

exceptionSupplier - that should provide Exception in case of Right Either

Returns:

value in case the Either is of type Left

Throws:

T - Exception provided via exceptionSupplier if value is defined as Right Either.

T extends java.lang.Throwable

getRightOrThrow

public abstract <T extends java.lang.Throwable> R getRightOrThrow(java.util.function.Supplier<? extends T> exceptionSupplier)
                                                           throws T extends java.lang.Throwable

Returns wrapped value in case the Either is of type Right. Throws Exception provided via exceptionSupplier if value is defined as Left Either.

Type Parameters:

T - type of Exception that will be provided by exceptionSupplier

Parameters:

exceptionSupplier - that should provide Exception in case of Left Either

Returns:

value in case the Either is of type Right

Throws:

T - Exception provided via exceptionSupplier if value is defined as Left Either.

T extends java.lang.Throwable

map

public abstract <L2,R2> Either<L2,R2> map(java.util.function.Function<L,L2> leftValueMapper,
                                          java.util.function.Function<R,R2> rightValueMapper)

Applies provided leftValueMapper to transform wrapped value if value is defined as Left Either. Applies provided rightValueMapper to transform wrapped value if value is defined as Right Either.

Type Parameters:

L2 - new type of Left Either value

R2 - new type of Right Either value

Parameters:

leftValueMapper - function that is applied Left Either value

rightValueMapper - function that is applied Right Either value

Returns:

modified Either

mapLeft

public abstract <L2> Either<L2,R> mapLeft(java.util.function.Function<L,L2> leftValueMapper)

Applies provided leftValueMapper to transform wrapped value if value is defined as Left Either. The leftValueMapper is ignored if value is defined as Right Either.

Type Parameters:

L2 - new type of Left Either value

Parameters:

leftValueMapper - function that is applied Left Either value

Returns:

modified Either

mapRight

public abstract <R2> Either<L,R2> mapRight(java.util.function.Function<R,R2> rightValueMapper)

Applies provided rightValueMapper to transform wrapped value if value is defined as Right Either. The rightValueMapper is ignored if value is defined as Left Either.

Type Parameters:

R2 - new type of Right Either value

Parameters:

rightValueMapper - function that is applied Right Either value

Returns:

modified Either

fold

public abstract <T> T fold(java.util.function.Function<L,T> foldLeft,
                           java.util.function.Function<R,T> foldRight)

Transforms a value and returns it

Type Parameters:

T - type of output value

Parameters:

foldLeft - function to map Left value into output value

foldRight - function to map Right value into output value

Returns:

transformed value

handleLeft

public abstract <T extends java.lang.Throwable> Either<L,R> handleLeft(ValueHandler<? super L,? extends T> leftValueHandler)
                                                                throws T extends java.lang.Throwable

Executes provided leftValueHandler if value is defined as Left Either. The action is ignored if value is defined as Right Either.

Type Parameters:

T - class of potential Throwable thrown by leftValueHandler

Parameters:

leftValueHandler - action that is executed for Left Either

Returns:

the same instance of Either to allow method chaining

Throws:

T - in case the leftValueHandler throws T

T extends java.lang.Throwable

handleRight

public abstract <T extends java.lang.Throwable> Either<L,R> handleRight(ValueHandler<? super R,? extends T> rightValueHandler)
                                                                 throws T extends java.lang.Throwable

Executes provided rightValueHandler if value is defined as Right Either. The action is ignored if value is defined as Left Either.

Type Parameters:

T - class of potential Throwable thrown by rightValueHandler

Parameters:

rightValueHandler - action that is executed for Right Either

Returns:

the same instance of Either to allow method chaining

Throws:

T - in case the rightValueHandler throws T

T extends java.lang.Throwable

handle

public abstract <TL extends java.lang.Throwable,TR extends java.lang.Throwable> Either<L,R> handle(ValueHandler<? super L,? extends TL> leftValueHandler,
                                                                                                   ValueHandler<? super R,? extends TR> rightValueHandler)
                                                                                            throws TL extends java.lang.Throwable,
                                                                                                   TR extends java.lang.Throwable

Executes provided leftValueHandler if value is defined as Left Either. Executes provided rightValueHandler if value is defined as Right Either.

Type Parameters:

TL - class of potential Throwable thrown by leftValueHandler

TR - class of potential Throwable thrown by rightValueHandler

Parameters:

leftValueHandler - action that is executed for Left Either

rightValueHandler - action that is executed for Right Either

Returns:

the same instance of Either to allow method chaining

Throws:

TL - in case the leftValueHandler throws T

TR - in case the rightValueHandler throws T

TL extends java.lang.Throwable

ifLeftThrow

public abstract <T extends java.lang.Throwable> Either<L,R> ifLeftThrow(java.util.function.Function<L,? extends T> exceptionSupplier)
                                                                 throws T extends java.lang.Throwable

Throws Exception provided via exceptionSupplier if value is defined as Left Either. The exceptionSupplier is ignored if value is defined as Right Either.

Type Parameters:

T - type of Exception that will be provided by exceptionSupplier

Parameters:

exceptionSupplier - that should provide Exception in case of Left Either

Returns:

the same instance to allow method chaining

Throws:

T - Exception provided via exceptionSupplier if value is defined as Left Either.

T extends java.lang.Throwable

ifRightThrow

public abstract <T extends java.lang.Throwable> Either<L,R> ifRightThrow(java.util.function.Function<R,? extends T> exceptionSupplier)
                                                                  throws T extends java.lang.Throwable

Throws Exception provided via exceptionSupplier if value is defined as Right Either. The exceptionSupplier is ignored if value is defined as Left Either.

Type Parameters:

T - type of Exception that will be provided by exceptionSupplier

Parameters:

exceptionSupplier - that should provide Exception in case of Right Either

Returns:

the same instance to allow method chaining

Throws:

T - Exception provided via exceptionSupplier if value is defined as Right Either

T extends java.lang.Throwable

value

public abstract java.lang.Object value()

Returns left value if of type Either.Left or right value if of type Either.Right

Specified by:

value in interface Value<java.lang.Object>

Returns:

either left or right value (depending on which one is defined)