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appdevreferencedaml-standard-libraryda-validation

DA.Validation

Documentation Index

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DA.Validation

Reference documentation for Daml module DA.Validation.

DA.Validation

Validation type and associated functions.

Module Snapshot

Stable. Status: `active` Introduced in: `3.4.9` Removed in: `-` Warnings: `0` Deprecations: `0` Deprecated since: `-`

Data Types

data Validation err a

A Validation represents eithor a non-empty list of errors, or a successful value. This generalizes Either to allow more than one error to be collected.

Constructors:

  • Errors (NonEmpty err)
  • Success a

Instances:

  • instance Foldable (Validation err)
  • instance Applicative (Validation err)
  • instance Semigroup (Validation err a)
  • instance Traversable (Validation err)
  • instance Functor (Validation err)
  • instance (Eq err, Eq a) => Eq (Validation err a)
  • instance (Show err, Show a) => Show (Validation err a)

Functions

invalid

invalid : err -> Validation err a

Fail for the given reason.

ok

ok : a -> Validation err a

Succeed with the given value.

validate

validate : Either err a -> Validation err a

Turn an Either into a Validation.

run

run : Validation err a -> Either (NonEmpty err) a

Convert a Validation err a value into an Either, taking the non-empty list of errors as the left value.

run1

run1 : Validation err a -> Either err a

Convert a Validation err a value into an Either, taking just the first error as the left value.

runWithDefault

runWithDefault : a -> Validation err a -> a

Run a Validation err a with a default value in case of errors.

<?>

<?> : Optional b -> err -> Validation err b

Convert an Optional t into a Validation err t, or more generally into an m t for any ActionFail type m.

Orphan Typeclass Instances

  • instance (Eq err, Eq a) => Eq (Validation err a)

  • instance (Show err, Show a) => Show (Validation err a)

  • instance Functor (Validation err)

  • instance Applicative (Validation err)

  • instance Semigroup (Validation err a)

  • instance Foldable (Validation err)

  • instance Traversable (Validation err)

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