Packages

sealed abstract class Maybe[A] extends AnyRef

An optional value

A Maybe[A] will either be a wrapped A instance (Just[A]), or a lack of underlying A instance (Empty[A]).

Maybe[A] is isomorphic to Option[A], however there are some differences between the two. Maybe is invariant in A while Option is covariant. Maybe[A] does not expose an unsafe get operation to access the underlying A value (that may not exist) like Option[A] does. Maybe[A] does not come with an implicit conversion to Iterable[A] (a trait with over a dozen super types).

Source
Maybe.scala
Linear Supertypes
AnyRef, Any
Known Subclasses
Empty, Just
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Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. final def <\/[B](b: ⇒ B): \/[A, B]

    alias for toLeft

  4. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  5. final def \/>[B](b: ⇒ B): \/[B, A]

    alias for toRight

  6. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  7. final def cata[B](f: (A) ⇒ B, b: ⇒ B): B

    Catamorphism.

    Catamorphism. Run the given function on the underlying value if present, otherwise return the provided fallback value

  8. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  9. final def cobind[B](f: (Maybe[A]) ⇒ B): Maybe[B]
  10. final def cojoin: Maybe[Maybe[A]]
  11. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  12. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  13. final def exists(f: (A) ⇒ Boolean): Boolean

    Return true if this is a Maybe.Just and the underlying value satisfies the provided predicate

  14. final def filter(f: (A) ⇒ Boolean): Maybe[A]
  15. final def filterNot(f: (A) ⇒ Boolean): Maybe[A]
  16. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  17. final def first: FirstMaybe[A]

    Tag with Tags.First

  18. final def flatMap[B](f: (A) ⇒ Maybe[B]): Maybe[B]
  19. final def forall(f: (A) ⇒ Boolean): Boolean

    Return true if this is a Maybe.Empty or if this is a Maybe.Just and the underlying value satisfies the provided predicate

  20. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  21. final def getOrElse(a: ⇒ A): A

    Return the underlying value if present, otherwise the provided fallback value

  22. final def getOrElseF[F[_]](fa: ⇒ F[A])(implicit arg0: Applicative[F]): F[A]
  23. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  24. final def isEmpty: Boolean

    True if no underlying value is present

  25. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  26. final def isJust: Boolean

    True if an underlying value is present

  27. final def last: LastMaybe[A]

    Tag with Tags.Last

  28. final def map[B](f: (A) ⇒ B): Maybe[B]
  29. final def max: MaxMaybe[A]

    Tag with Tags.Max

  30. final def min: MinMaybe[A]

    Tag with Tags.Min

  31. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  32. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  33. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  34. final def orElse(oa: ⇒ Maybe[A]): Maybe[A]

    Return this instance if it is a Maybe.Just, otherwise the provided fallback

  35. final def orEmpty[F[_]](implicit F: Applicative[F], G: PlusEmpty[F]): F[A]

    Return the underlying value wrapped in type F if present, otherwise the empty value for type F

  36. final def orError[F[_], E](e: E)(implicit F: MonadError[F, E]): F[A]
  37. final def orZero(implicit F: Monoid[A]): A

    Return the underlying value if present, otherwise the monoid zero

  38. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  39. final def toFailure[B](b: ⇒ B): Validation[A, B]

    Turn the underlying value into a failure validation if present, otherwise return a success validation with the provided fallback value

  40. final def toLeft[B](b: ⇒ B): \/[A, B]

    Turn the underlying value into a left disjunction if present, otherwise return a right disjunction with the provided fallback value

  41. final def toOption: Option[A]

    Convert to a standard library Option

  42. final def toRight[B](b: ⇒ B): \/[B, A]

    Turn the underlying value into a right disjunction if present, otherwise return a left disjunction with the provided fallback value

  43. def toString(): String
    Definition Classes
    AnyRef → Any
  44. final def toSuccess[B](b: ⇒ B): Validation[B, A]

    Turn the underlying value into a success validation if present, otherwise return a failure validation with the provided fallback value

  45. final def unary_~(implicit z: Monoid[A]): A

    alias for orZero

  46. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  47. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  48. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  49. final def zip[B](fb: Maybe[B]): Maybe[(A, B)]
  50. final def zipWith[B, C](fb: Maybe[B])(f: (A, B) ⇒ C): Maybe[C]
  51. final def |(a: ⇒ A): A

    alias for getOrElse

Inherited from AnyRef

Inherited from Any

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