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


-- | Abstraction over management of resources
--   
--   An implementation of the abstraction suggested in <a>a blog-post by
--   Gabriel Gonzalez</a>.
@package acquire
@version 0.3.6

module Acquire

-- | Acquire resources and use them by lifting IO into acquire.
acquire :: Acquire a -> IO a

-- | Execute an action, which uses a resource, having a resource provider.
acquireAndUse :: Acquire env -> Use env err res -> IO (Either err res)

-- | Run use on an acquired environment.
useAcquired :: env -> Use env err res -> IO (Either err res)

-- | Resource provider. Abstracts over resource acquisition and releasing.
--   
--   Composes well, allowing you to merge multiple providers into one.
--   
--   Implementation of
--   <a>http://www.haskellforall.com/2013/06/the-resource-applicative.html</a>
newtype Acquire env
Acquire :: IO (env, IO ()) -> Acquire env

-- | Construct <a>Acquire</a> by specifying a resource initializer and
--   finalizer actions.
startAndStop :: IO a -> (a -> IO ()) -> Acquire a

-- | Resource handler, which has a notion of pure errors.
newtype Use env err res
Use :: ReaderT env (ExceptT err IO) res -> Use env err res

-- | Map the environment of a resource handler.
mapEnv :: (b -> a) -> Use a err res -> Use b err res

-- | Map the error of a resource handler.
mapErr :: (a -> b) -> Use env a res -> Use env b res

-- | Map both the environment and the error of a resource handler.
mapEnvAndErr :: (envB -> envA) -> (errA -> errB) -> Use envA errA res -> Use envB errB res
instance Control.Monad.Reader.Class.MonadReader env (Acquire.Use env err)
instance Control.Monad.Error.Class.MonadError err (Acquire.Use env err)
instance Control.Monad.IO.Class.MonadIO (Acquire.Use env err)
instance GHC.Base.Monoid err => GHC.Base.MonadPlus (Acquire.Use env err)
instance GHC.Base.Monad (Acquire.Use env err)
instance GHC.Base.Monoid err => GHC.Base.Alternative (Acquire.Use env err)
instance GHC.Base.Applicative (Acquire.Use env err)
instance GHC.Base.Functor (Acquire.Use env err)
instance Data.Bifunctor.Bifunctor (Acquire.Use env)
instance GHC.Base.Functor Acquire.Acquire
instance GHC.Base.Applicative Acquire.Acquire
instance GHC.Base.Monad Acquire.Acquire
instance Control.Monad.IO.Class.MonadIO Acquire.Acquire