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


-- | Extensible type-safe unions
--   
--   Extensible type-safe unions for Haskell with prisms using modern GHC
--   features. Dual to vinyl records. Unions are also known as corecords or
--   polymorphic variants. Neither requires a <tt>Typeable</tt> constraint
--   nor uses unsafe coercions at the cost of linear time access
--   (negligible in practice).
@package union
@version 0.1.2


-- | Extensible type-safe unions.
--   
--   <pre>
--   &gt;&gt;&gt; let a = openUnion # (5 :: Int) :: OpenUnion '[Bool, Int]
--   </pre>
--   
--   <pre>
--   &gt;&gt;&gt; a ^? openUnion @Int
--   Just 5
--   </pre>
--   
--   <pre>
--   &gt;&gt;&gt; a ^? openUnion @Bool
--   Nothing
--   </pre>
--   
--   <pre>
--   &gt;&gt;&gt; a ^? openUnion @Char
--   &lt;interactive&gt;:7:6: error:
--       • No instance for (UElem Char '[] (RIndex Char '[]))
--           arising from a use of ‘openUnion’
--       • In the second argument of ‘(^?)’, namely ‘openUnion @Char’
--         In the expression: a ^? openUnion @Char
--         In an equation for ‘it’: it = a ^? openUnion @Char
--   </pre>
module Data.Union

-- | A union is parameterized by a universe <tt>u</tt>, an interpretation
--   <tt>f</tt> and a list of labels <tt>as</tt>. The labels of the union
--   are given by inhabitants of the kind <tt>u</tt>; the type of values at
--   any label <tt>a :: u</tt> is given by its interpretation <tt>f a ::
--   *</tt>.
data Union (f :: u -> *) (as :: [u])
[This] :: !(f a) -> Union f (a : as)
[That] :: !(Union f as) -> Union f (a : as)

-- | Case analysis for unions.
union :: (Union f as -> c) -> (f a -> c) -> Union f (a : as) -> c

-- | Since a union with an empty list of labels is uninhabited, we can
--   recover any type from it.
absurdUnion :: Union f '[] -> a
umap :: (forall a. f a -> g a) -> Union f as -> Union g as
_This :: Prism (Union f (a : as)) (Union f (b : as)) (f a) (f b)
_That :: Prism (Union f (a : as)) (Union f (a : bs)) (Union f as) (Union f bs)
class i ~ RIndex a as => UElem (a :: u) (as :: [u]) (i :: Nat)
uprism :: UElem a as i => Prism' (Union f as) (f a)
ulift :: UElem a as i => f a -> Union f as
umatch :: UElem a as i => Union f as -> Maybe (f a)
class is ~ RImage as bs => USubset (as :: [u]) (bs :: [u]) is
usubset :: USubset as bs is => Prism' (Union f bs) (Union f as)
urelax :: USubset as bs is => Union f as -> Union f bs
urestrict :: USubset as bs is => Union f bs -> Maybe (Union f as)
type OpenUnion = Union Identity
openUnion :: forall a as. UElem a as (RIndex a as) => Prism' (OpenUnion as) a
instance forall u (bs :: [u]). Data.Union.USubset '[] bs '[]
instance forall u (a :: u) (bs :: [u]) (i :: Data.Vinyl.TypeLevel.Nat) (as :: [u]) (is :: [Data.Vinyl.TypeLevel.Nat]). (Data.Union.UElem a bs i, Data.Union.USubset as bs is) => Data.Union.USubset (a : as) bs (i : is)
instance forall a1 (a2 :: a1) (as :: [a1]). Data.Union.UElem a2 (a2 : as) 'Data.Vinyl.TypeLevel.Z
instance forall a1 (a2 :: a1) (b :: a1) (as :: [a1]) (i :: Data.Vinyl.TypeLevel.Nat). (Data.Vinyl.TypeLevel.RIndex a2 (b : as) ~ 'Data.Vinyl.TypeLevel.S i, Data.Union.UElem a2 as i) => Data.Union.UElem a2 (b : as) ('Data.Vinyl.TypeLevel.S i)
instance forall u (f :: u -> *). Control.DeepSeq.NFData (Data.Union.Union f '[])
instance forall a1 (f :: a1 -> *) (a2 :: a1) (as :: [a1]). (Control.DeepSeq.NFData (f a2), Control.DeepSeq.NFData (Data.Union.Union f as)) => Control.DeepSeq.NFData (Data.Union.Union f (a2 : as))
instance forall u (f :: u -> *). GHC.Show.Show (Data.Union.Union f '[])
instance forall a1 (f :: a1 -> *) (a2 :: a1) (as :: [a1]). (GHC.Show.Show (f a2), GHC.Show.Show (Data.Union.Union f as)) => GHC.Show.Show (Data.Union.Union f (a2 : as))
instance forall u (f :: u -> *). GHC.Classes.Eq (Data.Union.Union f '[])
instance forall a1 (f :: a1 -> *) (a2 :: a1) (as :: [a1]). (GHC.Classes.Eq (f a2), GHC.Classes.Eq (Data.Union.Union f as)) => GHC.Classes.Eq (Data.Union.Union f (a2 : as))
instance forall u (f :: u -> *). GHC.Classes.Ord (Data.Union.Union f '[])
instance forall a1 (f :: a1 -> *) (a2 :: a1) (as :: [a1]). (GHC.Classes.Ord (f a2), GHC.Classes.Ord (Data.Union.Union f as)) => GHC.Classes.Ord (Data.Union.Union f (a2 : as))
instance (f ~ Data.Functor.Identity.Identity) => GHC.Exception.Exception (Data.Union.Union f '[])
instance (f ~ Data.Functor.Identity.Identity, GHC.Exception.Exception a, Data.Typeable.Internal.Typeable as, GHC.Exception.Exception (Data.Union.Union f as)) => GHC.Exception.Exception (Data.Union.Union f (a : as))
instance forall u (f :: u -> *). GHC.Generics.Generic (Data.Union.Union f '[])
instance forall u (f :: u -> *) (a :: u) (as :: [u]). GHC.Generics.Generic (Data.Union.Union f (a : as))
instance forall u (f :: u -> *). Data.Hashable.Class.Hashable (Data.Union.Union f '[])
instance forall a1 (f :: a1 -> *) (a2 :: a1) (as :: [a1]). (Data.Hashable.Class.Hashable (f a2), Data.Hashable.Class.Hashable (Data.Union.Union f as)) => Data.Hashable.Class.Hashable (Data.Union.Union f (a2 : as))