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


-- | Generic Haskell's Record Accessors
--   
--   Usage: <a>http://github.com/nonowarn/has/blob/master/README.md</a>
--   
--   And its test would be helpful:
--   <a>http://github.com/nonowarn/has/blob/master/test/Main.hs</a>
@package has
@version 0.2


-- | Provides some pliant data types and functions.
module Data.Has

-- | Represents Type level list.
data (:*:) a b
(:*:) :: a -> b -> :*: a b

-- | Provides plient function. Holds <tt>e == prj (inj e s)</tt> for all
--   <tt>s</tt> and <tt>e</tt>.
class Has e s
inj :: (Has e s) => e -> s -> s
prj :: (Has e s) => s -> e

-- | Updates a value <tt>e</tt> in <tt>s</tt>, using given function <tt>e
--   -&gt; e</tt>.
upd :: (Has e s) => (e -> e) -> s -> s
instance [overlap ok] (MayHas e s, Contains e s TyTrue) => Has e s