scala

trait Either

[source: scala/Either.scala]

sealed trait Either[+A, +B]
extends AnyRef

The Either type represents a value of one of two possible types (a disjoint union). The data constructors; Left and Right represent the two possible values. The Either type is often used as an alternative to scala.Option where Left represents failure (by convention) and Right is akin to Some.

Author
Tony Morris, Workingmouse
Version
1.0, 11/10/2008
Direct Known Subclasses:
Left, Right

Value Summary
lazy val isLeft : Boolean
lazy val isRight : Boolean
lazy val left : LeftProjection[A, B]
lazy val right : RightProjection[A, B]
lazy val swap : Either[B, A] with Product
Method Summary
def fold [X](fa : (A) => X, fb : (B) => X) : X
Deconstruction of the Either type (in contrast to pattern matching).
Methods inherited from AnyRef
getClass, hashCode, equals, clone, toString, notify, notifyAll, wait, wait, wait, finalize, ==, !=, eq, ne, synchronized
Methods inherited from Any
==, !=, isInstanceOf, asInstanceOf
Value Details
lazy val left : LeftProjection[A, B]

lazy val right : RightProjection[A, B]

lazy val swap : Either[B, A] with Product

lazy val isLeft : Boolean

lazy val isRight : Boolean

Method Details
def fold[X](fa : (A) => X, fb : (B) => X) : X
Deconstruction of the Either type (in contrast to pattern matching).