unexceptionalio (empty) → 0.1.0

raw patch · 4 files changed

+110/−0 lines, 4 filesdep +basedep +errorsdep +transformerssetup-changed

Dependencies added: base, errors, transformers

Files

COPYING +13/−0
Setup.hs +2/−0
UnexceptionalIO.hs +65/−0
unexceptionalio.cabal +30/−0

+ COPYING view

@@ -0,0 +1,13 @@+Copyright © 2011, Stephen Paul Weber <singpolyma.net>++Permission to use, copy, modify, and/or distribute this software for any+purpose with or without fee is hereby granted, provided that the above+copyright notice and this permission notice appear in all copies.++THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

+ Setup.hs view

@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain

+ UnexceptionalIO.hs view

@@ -0,0 +1,65 @@+-- | When you've caught all the exceptions that can be handled safely,+--   this is what you're left with.+--+-- > runEitherIO . fromIO ≡ id+module UnexceptionalIO (+	UnexceptionalIO,+	fromIO,+	runUnexceptionalIO,+	runEitherIO,+	-- * Unsafe entry points+	fromIO',+	unsafeFromIO+) where++import Control.Applicative (Applicative(..))+import Control.Monad (liftM, ap, (<=<))+import Control.Monad.Fix (MonadFix(..))+import Control.Error (syncIO, mapEitherT, EitherT(..), fmapLT)+import Control.Exception (SomeException, Exception, fromException, throwIO)+import Control.Monad.IO.Class (liftIO, MonadIO)++-- | IO without any non-error, synchronous exceptions+newtype UnexceptionalIO a = UnexceptionalIO (IO a)++instance Functor UnexceptionalIO where+	fmap = liftM++instance Applicative UnexceptionalIO where+	pure = return+	(<*>) = ap++instance Monad UnexceptionalIO where+	return = UnexceptionalIO . return+	(UnexceptionalIO x) >>= f = UnexceptionalIO (x >>= runUnexceptionalIO . f)++	fail s = error $ "UnexceptionalIO cannot fail (" ++ s ++ ")"++instance MonadFix UnexceptionalIO where+	mfix f = UnexceptionalIO (mfix $ runUnexceptionalIO . f)++-- | Catch any non-error, synchronous exceptions in an 'IO' action+fromIO :: IO a -> EitherT SomeException UnexceptionalIO a+fromIO = mapEitherT unsafeFromIO . syncIO++-- | Re-embed 'UnexceptionalIO' into 'IO'+runUnexceptionalIO :: (MonadIO m) => UnexceptionalIO a -> m a+runUnexceptionalIO (UnexceptionalIO io) = liftIO io++-- | Re-embed 'UnexceptionalIO' and possible exception back into 'IO'+runEitherIO :: (MonadIO m, Exception e) => EitherT e UnexceptionalIO a -> m a+runEitherIO = either (liftIO . throwIO) return <=< runUnexceptionalIO . runEitherT++-- | You promise that 'e' covers all non-error, synchronous exceptions+--   thrown by this 'IO' action+--+-- This function is partial if you lie+fromIO' :: (Exception e) => IO a -> EitherT e UnexceptionalIO a+fromIO' = fmapLT (maybePartial . fromException) . fromIO+	where+	maybePartial (Just x) = x+	maybePartial Nothing = error "UnexceptionalIO.fromIO' exception of unspecified type"++-- | You promise there are no exceptions thrown by this 'IO' action+unsafeFromIO :: IO a -> UnexceptionalIO a+unsafeFromIO = UnexceptionalIO

+ unexceptionalio.cabal view

@@ -0,0 +1,30 @@+name:            unexceptionalio+version:         0.1.0+cabal-version:   >=1.8+license:         OtherLicense+license-file:    COPYING+copyright:       © 2013 Stephen Paul Weber+category:        Control+author:          Stephen Paul Weber <singpolyma@singpolyma.net>+maintainer:      Stephen Paul Weber <singpolyma@singpolyma.net>+stability:       experimental+build-type:      Simple+homepage:        https://github.com/singpolyma/unexceptionalio+bug-reports:     http://github.com/singpolyma/unexceptionalio/issues+synopsis:        IO without any non-error, synchronous exceptions+description:+        When you've caught all the exceptions that can be handled safely,+        this is what you're left with.++library+        exposed-modules:+                UnexceptionalIO++        build-depends:+                base == 4.*,+                errors >= 1.4.2,+                transformers++source-repository head+        type:     git+        location: git://github.com/singpolyma/unexceptionalio.git