spoon 0.1 → 0.2

raw patch · 2 files changed

+41/−10 lines, 2 filesdep +deepseq

Dependencies added: deepseq

Files

• Control/Spoon.hs +38/−8
• spoon.cabal +3/−2

@@ -1,11 +1,41 @@-module Control.Spoon (spoon) where+{-# LANGUAGE ScopedTypeVariables #-} -import Prelude hiding (catch)-import System.IO.Unsafe (unsafePerformIO)-import Control.Exception (catch, SomeException)+-----------------------------------------------------------------------------+-- |+-- Module      :  Control.Spoon+-- Copyright   :  (c) Matt Morrow & Dan Peebles+-- License     :  see LICENSE+-- +-- Maintainer  :  pumpkingod@gmail.com+-- Stability   :  experimental+-- Portability :  non-portable (Scoped Type Variables)+--+-- Two functions for catching pureish exceptions in pure values. This library+-- considers pureish to be any error call or undefined, failed pattern matches, +-- arithmetic exceptions, and array bounds exceptions.+--+----------------------------------------------------------------------------- -catchAll :: IO a -> (SomeException -> IO a) -> IO a-catchAll = catch -spoon :: a -> Maybe a-spoon a = unsafePerformIO (catchAll (Just `fmap` (return $! a)) (return . const Nothing))+module Control.Spoon (spoon, teaspoon) where++import Control.Exception+import Control.DeepSeq+import System.IO.Unsafe++handlers :: [Handler (Maybe a)]+handlers = [ Handler $ \(_ :: ArithException) -> return Nothing+           , Handler $ \(_ :: ArrayException) -> return Nothing+           , Handler $ \(_ :: ErrorCall) -> return Nothing+           , Handler $ \(_ :: PatternMatchFail) -> return Nothing+           , Handler $ \(x :: SomeException) -> throwIO x+           ]++-- | Evaluate a value to normal form and return Nothing if any exceptions are thrown during evaluation. For any error-free value, @spoon = Just@.+spoon :: NFData a => a -> Maybe a+spoon a = unsafePerformIO $ (deepseq a (Just `fmap` return a)) `catches` handlers++-- | Like 'spoon', but only evaluates to WHNF.+teaspoon :: a -> Maybe a+teaspoon a = unsafePerformIO $ (Just `fmap` (return $! a)) `catches` handlers+

@@ -1,5 +1,5 @@ name:		      spoon-version:	    0.1+version:	    0.2 license:	    BSD3 license-file: LICENSE author:		    Matt Morrow, Dan Peebles@@ -14,7 +14,8 @@  library   build-depends: -    base >= 4 && < 5+    base >= 4 && < 5,+    deepseq >= 1   exposed-modules:     Control.Spoon   ghc-options: -Wall