data-accessor-mtl-0.2.0.3/0000755000000000000000000000000011741063724013350 5ustar0000000000000000data-accessor-mtl-0.2.0.3/data-accessor-mtl.cabal0000644000000000000000000000171011741063724017636 0ustar0000000000000000Name: data-accessor-mtl Version: 0.2.0.3 License: BSD3 License-File: LICENSE Author: Henning Thielemann Maintainer: Henning Thielemann Homepage: http://www.haskell.org/haskellwiki/Record_access Category: Data -- Default-Language: Haskell98 Cabal-Version: >=1.6 Build-Type: Simple Tested-With: GHC==6.8.2, GHC==6.10.4, GHC==6.12.3 Tested-With: GHC==7.0.1, GHC==7.4.1 Synopsis: Use Accessor to access state in mtl State monad class Description: Use Accessor to access state in mtl State monad class Source-Repository head Type: darcs Location: http://code.haskell.org/data-accessor/mtl/ Library Build-Depends: data-accessor >=0.2 && <0.4, mtl >=1.0 && <2.2, base >=1.0 && <5 Hs-Source-Dirs: src GHC-Options: -Wall Exposed-Modules: Data.Accessor.Monad.MTL.State data-accessor-mtl-0.2.0.3/Setup.lhs0000644000000000000000000000011511741063724015155 0ustar0000000000000000#! /usr/bin/env runhaskell > import Distribution.Simple > main = defaultMain data-accessor-mtl-0.2.0.3/LICENSE0000644000000000000000000000261211741063724014356 0ustar0000000000000000Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 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. Neither the name of the ; nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. 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 OWNER 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. data-accessor-mtl-0.2.0.3/src/0000755000000000000000000000000011741063724014137 5ustar0000000000000000data-accessor-mtl-0.2.0.3/src/Data/0000755000000000000000000000000011741063724015010 5ustar0000000000000000data-accessor-mtl-0.2.0.3/src/Data/Accessor/0000755000000000000000000000000011741063724016552 5ustar0000000000000000data-accessor-mtl-0.2.0.3/src/Data/Accessor/Monad/0000755000000000000000000000000011741063724017610 5ustar0000000000000000data-accessor-mtl-0.2.0.3/src/Data/Accessor/Monad/MTL/0000755000000000000000000000000011741063724020244 5ustar0000000000000000data-accessor-mtl-0.2.0.3/src/Data/Accessor/Monad/MTL/State.hs0000644000000000000000000000362711741063724021670 0ustar0000000000000000{- | Access helper functions in the State monad class -} module Data.Accessor.Monad.MTL.State where import qualified Data.Accessor.Basic as Accessor import qualified Control.Monad.State as State import qualified Control.Monad.Trans as Trans import Control.Monad.State (MonadState, State, runState, StateT(runStateT), ) import Control.Monad.Trans (MonadTrans, ) -- * accessors in the form of actions in the state monad set :: MonadState r m => Accessor.T r a -> a -> m () set f x = State.modify (Accessor.set f x) get :: MonadState r m => Accessor.T r a -> m a get f = State.gets (Accessor.get f) modify :: MonadState r m => Accessor.T r a -> (a -> a) -> m () modify f g = State.modify (Accessor.modify f g) {- | Modify a record element and return its old value. -} getAndModify :: MonadState r m => Accessor.T r a -> (a -> a) -> m a getAndModify f g = do x <- get f modify f g return x {- | Modify a record element and return its new value. -} modifyAndGet :: MonadState r m => Accessor.T r a -> (a -> a) -> m a modifyAndGet f g = do modify f g get f infix 1 %=, %: {- | Infix variant of 'set'. -} (%=) :: MonadState r m => Accessor.T r a -> a -> m () (%=) = set {- | Infix variant of 'modify'. -} (%:) :: MonadState r m => Accessor.T r a -> (a -> a) -> m () (%:) = modify -- * lift a state monadic accessor to an accessor of a parent record lift :: (MonadState r mr) => Accessor.T r s -> State s a -> mr a lift f m = do s0 <- get f let (a,s1) = runState m s0 set f s1 return a -- liftT :: (Monad m) => -- Accessor.T r s -> StateT s m a -> StateT r m a liftT :: (Monad m, MonadTrans t, MonadState r (t m)) => Accessor.T r s -> StateT s m a -> t m a liftT f m = do s0 <- get f (a,s1) <- Trans.lift $ runStateT m s0 set f s1 return a {- not possible in this generality lift :: (MonadState r mr, MonadState s ms) => Accessor.T r s -> ms a -> mr a -}