root/scalaz/Optional

Optional

trait Optional[F[_]]

Abstraction over a container/context which may or may not provide a value.

Type Params
F

the container/context type

See also
Companion
object
class Object
trait Matchable
class Any

Value members

Abstract methods

def pextract[B, A](fa: F[A]): F[B] \/ A

If fa has an a, return it; otherwise it must be universally quantified.

If fa has an a, return it; otherwise it must be universally quantified.

Concrete methods

def ?[A, X](fa: F[A])(some: => X, none: => X): X

Returns some if this context is defined, otherwise none.

Returns some if this context is defined, otherwise none.

def getOrElse[A](fa: F[A])(default: => A): A

Returns the value within the context if defined or else the value of default.

Returns the value within the context if defined or else the value of default.

def isDefined[A](fa: F[A]): Boolean

Returns true if a value is defined within the context.

Returns true if a value is defined within the context.

final
def isEmpty[A](fa: F[A]): Boolean

Returns true if no value is defined within the context.

Returns true if no value is defined within the context.

final
def nonEmpty[A](fa: F[A]): Boolean

Returns true if a value is defined within the context. This is an alias for isDefined.

Returns true if a value is defined within the context. This is an alias for isDefined.

def orElse[A](fa: F[A])(alternative: => F[A]): F[A]

Returns given context if it is defined or else the value of the alternative.

Returns given context if it is defined or else the value of the alternative.

def toMaybe[A](fa: F[A]): Maybe[A]

Returns this context converted to the Maybe context.

Returns this context converted to the Maybe context.

def toOption[A](fa: F[A]): Option[A]

Returns this context converted to the Option context.

Returns this context converted to the Option context.

Concrete fields