Hoogle Search

Within LTS Haskell 24.24 (ghc-9.10.3)

Note that Stackage only displays results for the latest LTS and Nightly snapshot. Learn more.

Exact lookup

1. data Validation (m :: Type -> Type)

   graphql	Language.GraphQL.Validate.Validation

   Validation rule context.

2. Validation :: Document -> Schema m -> Validation (m :: Type -> Type)

   graphql	Language.GraphQL.Validate.Validation

   No documentation available.

3. module PostgresqlSyntax.Validation

   No documentation available.

4. module Validation

   Lightweight pure data validation based on Applicative and Selective functors. Validation allows to accumulate all errors instead of short-circuting on the first error so you can display all possible errors at once. Common use-cases include:

   1. Validating each input of a form with multiple inputs.
   2. Performing multiple validations of a single value.
   Validation provides modular and composable interface which means that you can implement validations for different pieces of your data independently, and then combine smaller parts into the validation of a bigger type. The below table illustrates main ways to combine two Validations: TODO: table In other words, instances of different standard typeclasses provide various semantics which can be useful in different use-cases:
   1. Semigroup: accumulate both Failure and Success with <>.
   2. Monoid: Success that stores mempty.
   3. Functor: change the type inside Success.
   4. Bifunctor: change both Failure and Success.
   5. Applicative: apply function to values inside Success and accumulate errors inside Failure.
   6. Alternative: return the first Success or accumulate all errors inside Failure.
   7. Selective: choose which validations to apply based on the value inside.

5. data Validation e a

   validation-selective	Validation

   Validation is a polymorphic sum type for storing either all validation failures or validation success. Unlike Either, which returns only the first error, Validation accumulates all errors using the Semigroup typeclass. Usually type variables in Validation e a are used as follows:

   • e: is a list or set of failure messages or values of some error data type.
   • a: is some domain type denoting successful validation result.
   Some typical use-cases:

   • Validation [String] User

     • Either list of String error messages or a validated value of a custom User type.

   • Validation (NonEmpty UserValidationError)
     User

     • Similar to previous example, but list of failures guaranteed to be non-empty in case of validation failure, and it stores values of some custom error type.

6. module Validation

   No documentation available.

7. module Crypto.Noise.Internal.Handshake.Validation

   No documentation available.

8. module Crypto.Noise.Validation

   No documentation available.

9. module Configuration.Utils.Validation

   Utilities for validating configuration values

10. module OptEnvConf.Validation

    No documentation available.

Page 3 of many | Previous | Next