jedi.either
Class Either<A,B>

java.lang.Object
  jedi.either.Either<A,B>

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

Left, Right

public abstract class Either<A,B>
extends Object
implements Serializable

The Either type represents a value of one of two possible types (a disjoint union) and was Inspired by Scala's Either.

See Also:

Serialized Form

Constructor Summary

Either()

Method Summary

abstract List<A>	asList()
static <A,B> Either<A,B>	cond(boolean cond, A a, B b) If the condition satisfies, return the given A in Left, otherwise, return the given B in Right.
static <A,B> Either<A,B>	cond(boolean cond, Functor0<A> a, Functor0<B> b) If the condition satisfies, return the result of executing a in Left, otherwise, return the result of executing b in Right.
abstract void	execute(Command<A> ca, Command<B> cb)
abstract <X> Either<X,B>	flatMap(Functor<? super A,Either<X,B>> f)
abstract <X> X	fold(Functor<? super A,X> fa, Functor<? super B,X> fb) Deconstruction of the type.
boolean	isLeft()
boolean	isRight()
LeftProjection<A,B>	left()
abstract <X> Either<X,B>	map(Functor<? super A,X> f) Maps the function argument through Left.
RightProjection<A,B>	right()
abstract Either<B,A>	swap()

Methods inherited from class java.lang.Object

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

Constructor Detail

Either

public Either()

Method Detail

cond

public static <A,B> Either<A,B> cond(boolean cond,
                                     A a,
                                     B b)

If the condition satisfies, return the given A in Left, otherwise, return the given B in Right.

cond

public static <A,B> Either<A,B> cond(boolean cond,
                                     Functor0<A> a,
                                     Functor0<B> b)

If the condition satisfies, return the result of executing a in Left, otherwise, return the result of executing b in Right.

isLeft

public boolean isLeft()

isRight

public boolean isRight()

left

public LeftProjection<A,B> left()

right

public RightProjection<A,B> right()

fold

public abstract <X> X fold(Functor<? super A,X> fa,
                           Functor<? super B,X> fb)

Deconstruction of the type.

Parameters:

fa - the functor to apply if this is a Left

fb - the functor to apply if this is a Left

Returns:

the result of applying the appropriate functor.

execute

public abstract void execute(Command<A> ca,
                             Command<B> cb)

swap

public abstract Either<B,A> swap()

asList

public abstract List<A> asList()

Returns:

Singleton list if Lift or empty list if Right.

map

public abstract <X> Either<X,B> map(Functor<? super A,X> f)

Maps the function argument through Left.

flatMap

public abstract <X> Either<X,B> flatMap(Functor<? super A,Either<X,B>> f)