Scala Library


scala/Either.scala
]
sealed abstract
class
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
.
Method Summary  
def

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

isLeft
: Boolean
Returns
true if this is a Left , false otherwise. 
def

isRight
: Boolean
Returns
true if this is a Right , false otherwise. 
def

left
: LeftProjection[A, B]
Projects this
Either as a Left . 
def

right
: RightProjection[A, B]
Projects this
Either as a Right . 
def

swap
: Either[B, A] with Product
If this is a
Left , then return the left value in Right or vice versa. 
Methods inherited from AnyRef  
getClass, hashCode, equals, clone, toString, notify, notifyAll, wait, wait, wait, finalize, ==, !=, eq, ne, synchronized 
Methods inherited from Any  
==, !=, isInstanceOf, asInstanceOf 
Method Details 
def
left : LeftProjection[A, B]
Either
as a Left
.
def
right : RightProjection[A, B]
Either
as a Right
.Either
type (in contrast to pattern matching).Left
, then return the left value in Right
or vice versa.
def
isLeft : Boolean
true
if this is a Left
, false
otherwise.
def
isRight : Boolean
true
if this is a Right
, false
otherwise.
Scala Library

