--
--   Copyright (c) 2013, Carl Joachim Svenn
--   All rights reserved.
--   
--   Redistribution and use in source and binary forms, with or without 
--   modification, are permitted provided that the following conditions are met:
--   
--       1. Redistributions of source code must retain the above copyright notice, this 
--          list of conditions and the following disclaimer.
--       2. Redistributions in binary form must reproduce the above copyright notice, 
--          this list of conditions and the following disclaimer in the documentation 
--          and/or other materials provided with the distribution.
--   
--   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
--   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
--   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
--   DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE 
--   FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
--   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
--   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 
--   ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
--   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
--   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
--
module MEnv.Resource.IOS
  (
    resourceGet,
    resourceModify,
    resourceModifyIO,

  ) where


import MEnv.IOS
import qualified Control.Monad.State as MState


-- | get resource
resourceGet :: MEnv res res
resourceGet =
    MState.get


-- | modify resource
resourceModify :: (res -> res) -> MEnv res ()
resourceModify =
    MState.modify


-- | modify resource inside IO
resourceModifyIO :: (res -> IO res) -> MEnv res ()
resourceModifyIO f = do
    env <- MState.get
    env' <- MState.liftIO $ f $ env
    MState.put $ env'


