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DA.Validation

Validation type and associated functions.

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Module Snapshot

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Data Types

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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 (Serializable err, Serializable a) => Serializable (Validation err a)
• instance Functor (Validation err)
• instance (Eq err, Eq a) => Eq (Validation err a)
• instance (Show err, Show a) => Show (Validation err a)

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Functions

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invalid

invalid : err -> Validation err a Fail for the given reason.

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ok

ok : a -> Validation err a Succeed with the given value.

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validate

validate : Either err a -> Validation err a Turn an Either into a Validation.

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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.

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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.

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runWithDefault

runWithDefault : a -> Validation err a -> a Run a Validation err a with a default value in case of errors.

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<?>

<?> : 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.

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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)