-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | A data-type like Either but with an accumulating Applicative
--   
--   
--   A data-type like Either but with differing properties and type-class
--   instances.
--   
--   Library support is provided for this different representation, include
--   <a>lens</a>-related functions for converting between each and
--   abstracting over their similarities.
--   
--   <ul>
--   <li><a>AccValidation</a></li>
--   </ul>
--   
--   The <a>AccValidation</a> data type is isomorphic to <a>Either</a>, but
--   has an instance of <a>Applicative</a> that accumulates on the error
--   side. That is to say, if two (or more) errors are encountered, they
--   are appended using a <a>Semigroup</a> operation.
--   
--   As a consequence of this <a>Applicative</a> instance, there is no
--   corresponding <a>Bind</a> or <a>Monad</a> instance.
--   <a>AccValidation</a> is an example of, "An applicative functor that is
--   not a monad."
@package validation
@version 0.6.0


-- | Data types similar to <tt>Data.Either</tt> that are explicit about
--   failure and success.
module Data.Validation

-- | A value of the type <tt>err</tt> or <tt>a</tt>, however, the
--   <tt>Applicative</tt> instance accumulates values. This is witnessed by
--   the <tt>Semigroup</tt> context on the instance. <i>Note that there is
--   no Monad such that ap = (<a>*</a>).</i>
--   
--   <pre>
--   &gt;&gt;&gt; _Success # (+1) &lt;*&gt; _Success # 7 :: AccValidation String Int
--   AccSuccess 8
--   </pre>
--   
--   <pre>
--   &gt;&gt;&gt; _Failure # ["f1"] &lt;*&gt; _Success # 7 :: AccValidation [String] Int
--   AccFailure ["f1"]
--   </pre>
--   
--   <pre>
--   &gt;&gt;&gt; _Success # (+1) &lt;*&gt; _Failure # ["f2"] :: AccValidation [String] Int
--   AccFailure ["f2"]
--   </pre>
--   
--   <pre>
--   &gt;&gt;&gt; _Failure # ["f1"] &lt;*&gt; _Failure # ["f2"] :: AccValidation [String] Int
--   AccFailure ["f1","f2"]
--   </pre>
data AccValidation err a
AccFailure :: err -> AccValidation err a
AccSuccess :: a -> AccValidation err a
_Failure :: Validate f => Prism (f e1 a) (f e2 a) e1 e2
_Success :: Validate f => Prism (f e a) (f e b) a b
class Validate f where _Either = _EitherV
_AccValidation :: Validate f => Iso (f e a) (f g b) (AccValidation e a) (AccValidation g b)
_Either :: Validate f => Iso (f e a) (f g b) (Either e a) (Either g b)
instance (Data.Data.Data a, Data.Data.Data err) => Data.Data.Data (Data.Validation.AccValidation err a)
instance (GHC.Show.Show a, GHC.Show.Show err) => GHC.Show.Show (Data.Validation.AccValidation err a)
instance (GHC.Classes.Ord a, GHC.Classes.Ord err) => GHC.Classes.Ord (Data.Validation.AccValidation err a)
instance (GHC.Classes.Eq a, GHC.Classes.Eq err) => GHC.Classes.Eq (Data.Validation.AccValidation err a)
instance GHC.Base.Functor (Data.Validation.AccValidation err)
instance Data.Semigroup.Semigroup err => Data.Functor.Bind.Class.Apply (Data.Validation.AccValidation err)
instance Data.Semigroup.Semigroup err => GHC.Base.Applicative (Data.Validation.AccValidation err)
instance Data.Functor.Alt.Alt (Data.Validation.AccValidation err)
instance Data.Foldable.Foldable (Data.Validation.AccValidation err)
instance Data.Traversable.Traversable (Data.Validation.AccValidation err)
instance Data.Bifunctor.Bifunctor Data.Validation.AccValidation
instance Data.Bifoldable.Bifoldable Data.Validation.AccValidation
instance Data.Bitraversable.Bitraversable Data.Validation.AccValidation
instance Data.Semigroup.Semigroup e => Data.Semigroup.Semigroup (Data.Validation.AccValidation e a)
instance GHC.Base.Monoid e => GHC.Base.Monoid (Data.Validation.AccValidation e a)
instance Data.Validation.Validate Data.Validation.AccValidation
instance Data.Validation.Validate Data.Either.Either
instance Control.Lens.Iso.Swapped Data.Validation.AccValidation