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


-- | Closed type class declarations
--   
--   See <a>Data.Class.Closed</a> for explanation.
@package closed-classes
@version 0.1


-- | Closed type classes are defined by adding a private field with a
--   default implementation that requires a <a>Closed</a> constraint. For
--   example:
--   
--   <pre>
--   {-# LANGUAGE DefaultSignatures, FlexibleContexts #-}
--   
--   module Foo (Foo) where
--   
--   class Foo a where
--     default _private :: Closed Foo =&gt; Proxy a
--     _private :: Proxy a
--     _private = Proxy
--   
--   instance Foo Int where
--     _private = Proxy
--   </pre>
--   
--   Since <tt>_private</tt> is not exported, any new instance defined
--   outside the <tt>Foo</tt> module will be forced to use the default
--   implementation, which has the unsatisfiable <a>Closed</a> <tt>Foo</tt>
--   constraint.
--   
--   <pre>
--   module Bar where
--   
--   import Foo
--   
--   instance Foo Char -- • User defined Foo instances are not allowed.
--   </pre>
--   
--   Thus new instances can only be defined in the same module as
--   <tt>Foo</tt>, where <tt>_private</tt> is visible. Note that
--   <a>Closed</a> itself is a closed type class, implemented using the
--   same trick!
--   
--   To automatically generate the boilerplate, see
--   <a>Data.Class.Closed.TH</a>.
module Data.Class.Closed

-- | <a>Closed</a> constraints are unsatisfiable. Attempting to resolve a
--   <a>Closed</a> <tt>&lt;class&gt;</tt> constraint will result in
--   
--   <pre>
--   • User defined &lt;class&gt; instances are not allowed.
--   </pre>
class Closed (a :: k)
instance forall k (a :: k). (TypeError ...) => Data.Class.Closed.Closed a

module Data.Class.Closed.TH

-- | Closes all declared classes. Any instances must be given in the same
--   quote.
close :: Q [Dec] -> Q [Dec]

module Data.Class.Closed.Example
class Example₁ a_a5OY
example₁ :: Example₁ a_a5OY => a_a5OY
class Example₂ a_a5OZ b_a5P0
example₂ :: Example₂ a_a5OZ b_a5P0 => a_a5OZ -> Proxy (b_a5P0 :: Bool)
instance Data.Class.Closed.Example.Example₂ a 'GHC.Types.True
instance Data.Class.Closed.Example.Example₁ ()