Packages

sealed abstract class Validation[+E, +A] extends Product with Serializable

Represents either:

  • Success(a), or
  • Failure(e).

Isomorphic to scala.Either and scalaz.\/. The motivation for a Validation is to provide the instance Applicativea that accumulate failures through a scalaz.Semigroup[E].

scalaz.NonEmptyList is commonly chosen as a type constructor for the type E. As a convenience, an alias scalaz.ValidationNel[E] is provided as a shorthand for scalaz.Validation[NonEmptyList[E]], and a method Validation#toValidationNel converts Validation[E] to ValidationNel[E].

Example:

import scalaz._, std.AllInstances._

def parseInt(s: String): Validation[String, Int] =
  try { Success(s.toInt) } catch { case ex: NumberFormatException => Failure(ex.getMessage) }
val V = Applicative[ValidationNel[String, *]]

val x: ValidationNel[String, Int] =
  V.apply2(parseInt("1.x").toValidationNel, parseInt("1..0").toValidationNel)(_ * _)
  // Failure(NonEmptyList(For input string: "1..0", For input string: "1.x"))
E

The type of the Failure

A

The type of the Success

Source
Validation.scala
Linear Supertypes
Serializable, Serializable, Product, Equals, AnyRef, Any
Known Subclasses
Failure, Success
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Inherited
  1. Validation
  2. Serializable
  3. Serializable
  4. Product
  5. Equals
  6. AnyRef
  7. Any
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Visibility
  1. Public
  2. All

Type Members

  1. final class SwitchingValidation[X] extends AnyRef

Abstract Value Members

  1. abstract def canEqual(that: Any): Boolean
    Definition Classes
    Equals
  2. abstract def productArity: Int
    Definition Classes
    Product
  3. abstract def productElement(n: Int): Any
    Definition Classes
    Product

Concrete Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. def +++[EE >: E, AA >: A](x: ⇒ Validation[EE, AA])(implicit M1: Semigroup[AA], M2: Semigroup[EE]): Validation[EE, AA]

    Sums up values inside validation, if both are success or failure.

    Sums up values inside validation, if both are success or failure. Returns first failure otherwise.

    success(v1) +++ success(v2) → success(v1 + v2)
success(v1) +++ failure(v2) → failure(v2)
failure(v1) +++ success(v2) → failure(v1)
failure(v1) +++ failure(v2) → failure(v1 + v2)
  4. def +|+[EE >: E, AA >: A](x: Validation[EE, AA])(implicit es: Semigroup[EE], as: Semigroup[AA]): Validation[EE, AA]

    If this and that are both success, or both a failure, combine them with the provided Semigroup for each.

    If this and that are both success, or both a failure, combine them with the provided Semigroup for each. Otherwise, return the success. Alias for append

  5. def :?>>[X](success: ⇒ X): SwitchingValidation[X]

    If this validation is success, return the given X value, otherwise, return the X value given to the return value.

  6. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  7. def ===[EE >: E, AA >: A](x: Validation[EE, AA])(implicit EE: Equal[EE], EA: Equal[AA]): Boolean

    Compare two validations values for equality.

  8. def @\/[EE, AA](k: (\/[E, A]) ⇒ \/[EE, AA]): Validation[EE, AA]

    Run a disjunction function and back to validation again.

    Run a disjunction function and back to validation again. Alias for disjunctioned

  9. def andThen[EE >: E, B](f: (A) ⇒ Validation[EE, B]): Validation[EE, B]
  10. def ap[EE >: E, B](x: ⇒ Validation[EE, (A) ⇒ B])(implicit E: Semigroup[EE]): Validation[EE, B]

    Apply a function in the environment of the success of this validation, accumulating errors.

  11. def append[EE >: E, AA >: A](that: Validation[EE, AA])(implicit es: Semigroup[EE], as: Semigroup[AA]): Validation[EE, AA]

    If this and that are both success, or both a failure, combine them with the provided Semigroup for each.

    If this and that are both success, or both a failure, combine them with the provided Semigroup for each. Otherwise, return the success. Alias for +|+

  12. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  13. def bimap[C, D](f: (E) ⇒ C, g: (A) ⇒ D): Validation[C, D]

    Binary functor map on this validation.

  14. def bitraverse[G[_], C, D](f: (E) ⇒ G[C], g: (A) ⇒ G[D])(implicit arg0: Functor[G]): G[Validation[C, D]]

    Binary functor traverse on this validation.

  15. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  16. def compare[EE >: E, AA >: A](x: Validation[EE, AA])(implicit EE: Order[EE], EA: Order[AA]): Ordering

    Compare two validations values for ordering.

  17. def disjunction: \/[E, A]

    Convert to a disjunction.

  18. def disjunctioned[EE, AA](k: (\/[E, A]) ⇒ \/[EE, AA]): Validation[EE, AA]

    Run a disjunction function and back to validation again.

    Run a disjunction function and back to validation again. Alias for @\/

  19. def ensure[EE >: E](onFailure: ⇒ EE)(f: (A) ⇒ Boolean): Validation[EE, A]

    Ensures that the success value of this validation satisfies the given predicate, or fails with the given value.

  20. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  21. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  22. def excepting[EE >: E](pf: PartialFunction[A, EE]): Validation[EE, A]

    Return a Validation formed by the application of a partial function across the success of this value:

    Return a Validation formed by the application of a partial function across the success of this value:

    strings map (_.parseInt excepting { case i if i < 0 => new Exception(s"Int must be positive: $i") })
    Since

    7.0.2

  23. def exists(f: (A) ⇒ Boolean): Boolean

    Return true if this validation is a success value satisfying the given predicate.

  24. def filter[EE >: E](p: (A) ⇒ Boolean)(implicit M: Monoid[EE]): Validation[EE, A]

    Filter on the success of this validation.

  25. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  26. def findSuccess[EE >: E, AA >: A](that: ⇒ Validation[EE, AA])(implicit es: Semigroup[EE]): Validation[EE, AA]

    If this is a success, return it; otherwise, if that is a success, return it; otherwise, combine the failures with the specified semigroup.

  27. def fold[X](fail: (E) ⇒ X, succ: (A) ⇒ X): X

    Catamorphism.

    Catamorphism. Run the first given function if failure, otherwise, the second given function.

  28. def foldRight[B](z: ⇒ B)(f: (A, ⇒ B) ⇒ B): B

    Fold on the success of this validation.

  29. def forall(f: (A) ⇒ Boolean): Boolean

    Return true if this validation is a failure value or the success value satisfies the given predicate.

  30. def foreach[U](f: (A) ⇒ U): Unit

    Run the side-effect on the success of this validation.

  31. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  32. def getOrElse[AA >: A](x: ⇒ AA): AA

    Return the success value of this validation or the given default if failure.

    Return the success value of this validation or the given default if failure. Alias for |

  33. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  34. def isFailure: Boolean

    Return true if this validation is failure.

  35. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  36. def isSuccess: Boolean

    Return true if this validation is success.

  37. def leftMap[C](f: (E) ⇒ C): Validation[C, A]

    Run the given function on the left value.

  38. def loopFailure[EE >: E, AA >: A, X](success: (AA) ⇒ X, failure: (EE) ⇒ \/[X, Validation[EE, AA]]): X

    Spin in tail-position on the failure value of this validation.

  39. def loopSuccess[EE >: E, AA >: A, X](success: (AA) ⇒ \/[X, Validation[EE, AA]], failure: (EE) ⇒ X): X

    Spin in tail-position on the success value of this validation.

  40. def map[B](f: (A) ⇒ B): Validation[E, B]

    Map on the success of this validation.

  41. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  42. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  43. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  44. def orElse[EE >: E, AA >: A](x: ⇒ Validation[EE, AA]): Validation[EE, AA]

    Return this if it is a success, otherwise, return the given value.

    Return this if it is a success, otherwise, return the given value. Alias for |||

  45. def productIterator: Iterator[Any]
    Definition Classes
    Product
  46. def productPrefix: String
    Definition Classes
    Product
  47. def show[EE >: E, AA >: A](implicit SE: Show[EE], SA: Show[AA]): Cord

    Show for a validation value.

  48. def swap: Validation[A, E]

    Flip the failure/success values in this validation.

    Flip the failure/success values in this validation. Alias for unary_~

  49. def swapped[EE, AA](k: (Validation[A, E]) ⇒ Validation[AA, EE]): Validation[EE, AA]

    Run the given function on this swapped value.

    Run the given function on this swapped value. Alias for ~

  50. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  51. def toEither: Either[E, A]

    Convert to a core scala.Either at your own peril.

  52. def toList: List[A]

    Return an empty list or list with one element on the success of this validation.

  53. def toMaybe[AA >: A]: Maybe[AA]

    Return an empty maybe or maybe with the element on the success of this validation.

    Return an empty maybe or maybe with the element on the success of this validation. Useful to sweep errors under the carpet.

  54. def toOption: Option[A]

    Return an empty option or option with one element on the success of this validation.

    Return an empty option or option with one element on the success of this validation. Useful to sweep errors under the carpet.

  55. def toStream: Stream[A]

    Return an empty stream or stream with one element on the success of this validation.

  56. def toString(): String
    Definition Classes
    AnyRef → Any
  57. def toValidationNel[EE >: E, AA >: A]: ValidationNel[EE, AA]

    Wraps the failure value in a scalaz.NonEmptyList

  58. def traverse[G[_], EE >: E, B](f: (A) ⇒ G[B])(implicit arg0: Applicative[G]): G[Validation[EE, B]]

    Traverse on the success of this validation.

  59. def unary_~: Validation[A, E]

    Flip the failure/success values in this validation.

    Flip the failure/success values in this validation. Alias for swap

  60. def valueOr[AA >: A](x: (E) ⇒ AA): AA

    Return the success value of this validation or run the given function on the failure.

  61. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  62. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  63. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  64. def |[AA >: A](x: ⇒ AA): AA

    Return the success value of this validation or the given default if failure.

    Return the success value of this validation or the given default if failure. Alias for getOrElse

  65. def |||[EE >: E, AA >: A](x: ⇒ Validation[EE, AA]): Validation[EE, AA]

    Return this if it is a success, otherwise, return the given value.

    Return this if it is a success, otherwise, return the given value. Alias for orElse

  66. def ~[EE, AA](k: (Validation[A, E]) ⇒ Validation[AA, EE]): Validation[EE, AA]

    Run the given function on this swapped value.

    Run the given function on this swapped value. Alias for swapped

Inherited from Serializable

Inherited from Serializable

Inherited from Product

Inherited from Equals

Inherited from AnyRef

Inherited from Any

Ungrouped