Text.Digestive.Validate

Validators that can be attached to forms

Documentation

data Validator m e a

A validator. Invariant: the validator should not modify the result value, only check it.

Instances

Monad m => Monoid (Validator m e a)

validate :: Monad m => Form m i e v a -> Validator m e a -> Form m i e v a

Attach a validator to a form.

validateMany :: Monad m => Form m i e v a -> [Validator m e a] -> Form m i e v a

Attach multiple validators to a form.

check

Arguments

:: Monad m

=> e

Error message

-> (a -> Bool)

Actual validation

-> Validator m e a

Resulting validator

Easy way to create a pure validator

checkM

Arguments

:: Monad m

=> e

Error message

-> (a -> m Bool)

Actual validation

-> Validator m e a

Resulting validator

Easy way to create a monadic validator