Copyright	(c) 2016, Drew Hess
License	BSD3
Maintainer	Drew Hess <src@drewhess.com>
Stability	experimental
Portability	non-portable
Safe Haskell	Trustworthy
Language	Haskell2010

System.GPIO.Linux.Sysfs.IO

Contents

SysfsIOT transformer

Description

The actual Linux sysfs implementation. This implementation will only function properly on Linux systems with a sysfs subsystem, obviously.

Synopsis

SysfsIOT transformer

newtype SysfsIOT m a Source #

An instance of MonadSysfs which runs MonadSysfs operations in IO. This instance must be run on an actual Linux sysfs GPIO filesystem and will fail in any other environment.

Interactions with threads

Some parts of this implementation use the Haskell C FFI, and may block on C I/O operations. (Specifically, pollFile will block in the C FFI until its event is triggered.) When using this implementation with GHC, you should compile your program with the -threaded option, so that threads performing these blocking operations do not block other Haskell threads in the system.

Note that the C FFI bits in this implementation are marked as interruptible, so that, on versions of GHC later than 7.8.1, functions such as throwTo will work properly when targeting a Haskell thread that uses this implementation.

(On Haskell implementations other than GHC, the threading implications are unknown; see the implementation's notes on how its threading system interacts with the C FFI.)

Constructors

SysfsIOT
Fields runSysfsIOT :: m a

Instances

MonadTrans SysfsIOT Source #
Methods lift :: Monad m => m a -> SysfsIOT m a #
MonadRWS r w s m => MonadRWS r w s (SysfsIOT m) Source #

MonadError e m => MonadError e (SysfsIOT m) Source #
Methods throwError :: e -> SysfsIOT m a # catchError :: SysfsIOT m a -> (e -> SysfsIOT m a) -> SysfsIOT m a #
MonadReader r m => MonadReader r (SysfsIOT m) Source #
Methods ask :: SysfsIOT m r # local :: (r -> r) -> SysfsIOT m a -> SysfsIOT m a # reader :: (r -> a) -> SysfsIOT m a #
MonadState s m => MonadState s (SysfsIOT m) Source #
Methods get :: SysfsIOT m s # put :: s -> SysfsIOT m () # state :: (s -> (a, s)) -> SysfsIOT m a #
MonadWriter w m => MonadWriter w (SysfsIOT m) Source #
Methods writer :: (a, w) -> SysfsIOT m a # tell :: w -> SysfsIOT m () # listen :: SysfsIOT m a -> SysfsIOT m (a, w) # pass :: SysfsIOT m (a, w -> w) -> SysfsIOT m a #
Monad m => Monad (SysfsIOT m) Source #
Methods (>>=) :: SysfsIOT m a -> (a -> SysfsIOT m b) -> SysfsIOT m b # (>>) :: SysfsIOT m a -> SysfsIOT m b -> SysfsIOT m b # return :: a -> SysfsIOT m a # fail :: String -> SysfsIOT m a #
Functor m => Functor (SysfsIOT m) Source #
Methods fmap :: (a -> b) -> SysfsIOT m a -> SysfsIOT m b # (<$) :: a -> SysfsIOT m b -> SysfsIOT m a #
MonadFix m => MonadFix (SysfsIOT m) Source #
Methods mfix :: (a -> SysfsIOT m a) -> SysfsIOT m a #
Applicative m => Applicative (SysfsIOT m) Source #
Methods pure :: a -> SysfsIOT m a # (<>) :: SysfsIOT m (a -> b) -> SysfsIOT m a -> SysfsIOT m b # (>) :: SysfsIOT m a -> SysfsIOT m b -> SysfsIOT m b # (<*) :: SysfsIOT m a -> SysfsIOT m b -> SysfsIOT m a #
MonadIO m => MonadIO (SysfsIOT m) Source #
Methods liftIO :: IO a -> SysfsIOT m a #
Alternative m => Alternative (SysfsIOT m) Source #
Methods empty :: SysfsIOT m a # (<\|>) :: SysfsIOT m a -> SysfsIOT m a -> SysfsIOT m a # some :: SysfsIOT m a -> SysfsIOT m [a] # many :: SysfsIOT m a -> SysfsIOT m [a] #
MonadPlus m => MonadPlus (SysfsIOT m) Source #
Methods mzero :: SysfsIOT m a # mplus :: SysfsIOT m a -> SysfsIOT m a -> SysfsIOT m a #
MonadThrow m => MonadThrow (SysfsIOT m) Source #
Methods throwM :: Exception e => e -> SysfsIOT m a #
MonadCatch m => MonadCatch (SysfsIOT m) Source #
Methods catch :: Exception e => SysfsIOT m a -> (e -> SysfsIOT m a) -> SysfsIOT m a #
MonadMask m => MonadMask (SysfsIOT m) Source #
Methods mask :: ((forall a. SysfsIOT m a -> SysfsIOT m a) -> SysfsIOT m b) -> SysfsIOT m b # uninterruptibleMask :: ((forall a. SysfsIOT m a -> SysfsIOT m a) -> SysfsIOT m b) -> SysfsIOT m b #
MonadCont m => MonadCont (SysfsIOT m) Source #
Methods callCC :: ((a -> SysfsIOT m b) -> SysfsIOT m a) -> SysfsIOT m a #
(MonadIO m, MonadThrow m) => MonadSysfs (SysfsIOT m) Source #
Methods doesDirectoryExist :: FilePath -> SysfsIOT m Bool Source # doesFileExist :: FilePath -> SysfsIOT m Bool Source # getDirectoryContents :: FilePath -> SysfsIOT m [FilePath] Source # readFile :: FilePath -> SysfsIOT m ByteString Source # writeFile :: FilePath -> ByteString -> SysfsIOT m () Source # unlockedWriteFile :: FilePath -> ByteString -> SysfsIOT m () Source # pollFile :: FilePath -> Int -> SysfsIOT m CInt Source #