{-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE MultiParamTypeClasses #-} ----------------------------------------------------------------------------- -- | -- Module : Data.Dynamic.Lens -- Copyright : (C) 2012-2014 Edward Kmett -- License : BSD-style (see the file LICENSE) -- Maintainer : Edward Kmett <ekmett@gmail.com> -- Stability : experimental -- Portability : non-portable -- ---------------------------------------------------------------------------- module Data.Dynamic.Lens ( AsDynamic(..) ) where import Control.Exception import Control.Exception.Lens import Control.Lens import Data.Dynamic -- | Any 'Dynamic' can be thrown as an 'Exception' class AsDynamic t where -- | This 'Prism' allows you to traverse the typed value contained in a -- 'Dynamic' where the type required by your function matches that -- of the contents of the 'Dynamic', or construct a 'Dynamic' value -- out of whole cloth. It can also be used to catch or throw a 'Dynamic' -- value as 'SomeException'. -- -- @ -- '_Dynamic' :: 'Typeable' a => 'Prism'' 'Dynamic' a -- '_Dynamic' :: 'Typeable' a => 'Prism'' 'SomeException' a -- @ _Dynamic :: Typeable a => Prism' t a instance AsDynamic Dynamic where _Dynamic = prism' toDyn fromDynamic {-# INLINE _Dynamic #-} instance AsDynamic SomeException where _Dynamic = exception.prism' toDyn fromDynamic {-# INLINE _Dynamic #-}