Packages

final case class OptionT[F[_], A](value: F[Option[A]]) extends Product with Serializable

OptionT[F[_], A] is a light wrapper on an F[Option[A]] with some convenient methods for working with this nested structure.

It may also be said that OptionT is a monad transformer for Option.

For more information, see the documentation.

Source
OptionT.scala
Linear Supertypes
Serializable, Serializable, Product, Equals, AnyRef, Any
Type Hierarchy
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Inherited
  1. OptionT
  2. Serializable
  3. Serializable
  4. Product
  5. Equals
  6. AnyRef
  7. Any
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Visibility
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Instance Constructors

  1. new OptionT(value: F[Option[A]])

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. def ===(that: OptionT[F, A])(implicit eq: Eq[F[Option[A]]]): Boolean
  5. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  6. def cata[B](default: ⇒ B, f: (A) ⇒ B)(implicit F: Functor[F]): F[B]

    Catamorphism on the Option.

    Catamorphism on the Option. This is identical to fold, but it only has one parameter list, which can result in better type inference in some contexts.

  7. def cataF[B](default: ⇒ F[B], f: (A) ⇒ F[B])(implicit F: FlatMap[F]): F[B]

    Effectful catamorphism on the Option.

    Effectful catamorphism on the Option. This is identical to foldF, but it only has one parameter list, which can result in better type inference in some contexts.

  8. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native() @IntrinsicCandidate()
  9. def collect[B](f: PartialFunction[A, B])(implicit F: Functor[F]): OptionT[F, B]
  10. def compare(that: OptionT[F, A])(implicit o: Order[F[Option[A]]]): Int
  11. def contramap[B](f: (B) ⇒ A)(implicit F: Contravariant[F]): OptionT[F, B]
  12. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  13. def exists(f: (A) ⇒ Boolean)(implicit F: Functor[F]): F[Boolean]
  14. def filter(p: (A) ⇒ Boolean)(implicit F: Functor[F]): OptionT[F, A]
  15. def filterNot(p: (A) ⇒ Boolean)(implicit F: Functor[F]): OptionT[F, A]
  16. def flatMap[B](f: (A) ⇒ OptionT[F, B])(implicit F: Monad[F]): OptionT[F, B]
  17. def flatMapF[B](f: (A) ⇒ F[Option[B]])(implicit F: Monad[F]): OptionT[F, B]
  18. def flatTapNone[B](ifNone: ⇒ F[B])(implicit F: Monad[F]): OptionT[F, A]

    Perform an effect if the value inside the is a None, leaving the value untouched.

    Perform an effect if the value inside the is a None, leaving the value untouched. Equivalent to orElseF with an effect returning None as argument.

  19. def flatTransform[B](f: (Option[A]) ⇒ F[Option[B]])(implicit F: Monad[F]): OptionT[F, B]
  20. def fold[B](default: ⇒ B)(f: (A) ⇒ B)(implicit F: Functor[F]): F[B]
  21. def foldF[B](default: ⇒ F[B])(f: (A) ⇒ F[B])(implicit F: FlatMap[F]): F[B]

    Transform this OptionT[F, A] into a F[B].

    Transform this OptionT[F, A] into a F[B].

    Example:

    scala> import cats.implicits._
scala> import cats.data.OptionT

scala> val optionT: OptionT[List, Int] = OptionT[List, Int](List(Some(23), None))
scala> optionT.foldF(Nil)(v => List(v, v * 2))
res0: List[Int] = List(23, 46)
  22. def foldLeft[B](b: B)(f: (B, A) ⇒ B)(implicit F: Foldable[F]): B
  23. def foldRight[B](lb: Eval[B])(f: (A, Eval[B]) ⇒ Eval[B])(implicit F: Foldable[F]): Eval[B]
  24. def forall(f: (A) ⇒ Boolean)(implicit F: Functor[F]): F[Boolean]
  25. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native() @IntrinsicCandidate()
  26. def getOrElse[B >: A](default: ⇒ B)(implicit F: Functor[F]): F[B]
  27. def getOrElseF[B >: A](default: ⇒ F[B])(implicit F: Monad[F]): F[B]
  28. def imap[B](f: (A) ⇒ B)(g: (B) ⇒ A)(implicit F: Invariant[F]): OptionT[F, B]
  29. def isDefined(implicit F: Functor[F]): F[Boolean]
  30. def isEmpty(implicit F: Functor[F]): F[Boolean]
  31. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  32. def map[B](f: (A) ⇒ B)(implicit F: Functor[F]): OptionT[F, B]
  33. def mapFilter[B](f: (A) ⇒ Option[B])(implicit F: Functor[F]): OptionT[F, B]
  34. def mapK[G[_]](f: ~>[F, G]): OptionT[G, A]

    Modify the context F using transformation f.

  35. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  36. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @IntrinsicCandidate()
  37. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @IntrinsicCandidate()
  38. def orElse(default: ⇒ OptionT[F, A])(implicit F: Monad[F]): OptionT[F, A]
  39. def orElseF(default: ⇒ F[Option[A]])(implicit F: Monad[F]): OptionT[F, A]
  40. def partialCompare(that: OptionT[F, A])(implicit p: PartialOrder[F[Option[A]]]): Double
  41. def semiflatMap[B](f: (A) ⇒ F[B])(implicit F: Monad[F]): OptionT[F, B]
  42. def semiflatTap[B](f: (A) ⇒ F[B])(implicit F: Monad[F]): OptionT[F, A]
  43. def show(implicit F: Show[F[Option[A]]]): String
  44. def subflatMap[B](f: (A) ⇒ Option[B])(implicit F: Functor[F]): OptionT[F, B]
  45. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  46. def toLeft[R](right: ⇒ R)(implicit F: Functor[F]): EitherT[F, A, R]
  47. def toLeftF[R](right: ⇒ F[R])(implicit F: Monad[F]): EitherT[F, A, R]
  48. def toNested: Nested[F, Option, A]

    Transform this OptionT[F, A] into a Nested[F, Option, A].

    Transform this OptionT[F, A] into a Nested[F, Option, A].

    An example where toNested can be used, is to get the Apply.ap function with the behavior from the composed Apply instances from F and Option, which is inconsistent with the behavior of the ap from Monad of OptionT.

    scala> import cats.implicits._
scala> import cats.data.OptionT
scala> val ff: OptionT[List, Int => String] =
     |   OptionT(List(Option(_.toString), None))
scala> val fa: OptionT[List, Int] = OptionT(List(Option(1), Option(2)))
scala> ff.ap(fa)
res0: OptionT[List,String] = OptionT(List(Some(1), Some(2), None))
scala> OptionT(ff.toNested.ap(fa.toNested).value)
res1: OptionT[List,String] = OptionT(List(Some(1), Some(2), None, None))
  49. def toRight[L](left: ⇒ L)(implicit F: Functor[F]): EitherT[F, L, A]
  50. def toRightF[L](left: ⇒ F[L])(implicit F: Monad[F]): EitherT[F, L, A]
  51. def transform[B](f: (Option[A]) ⇒ Option[B])(implicit F: Functor[F]): OptionT[F, B]
  52. def traverse[G[_], B](f: (A) ⇒ G[B])(implicit F: Traverse[F], G: Applicative[G]): G[OptionT[F, B]]
  53. val value: F[Option[A]]
  54. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  55. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  56. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  57. def withFilter(p: (A) ⇒ Boolean)(implicit F: Functor[F]): OptionT[F, A]

Deprecated Value Members

  1. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] ) @Deprecated
    Deprecated

Inherited from Serializable

Inherited from Serializable

Inherited from Product

Inherited from Equals

Inherited from AnyRef

Inherited from Any

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