fail-4.9.0.0/0000755000000000000000000000000012650171571010770 5ustar0000000000000000fail-4.9.0.0/LICENSE0000644000000000000000000000303412650171571011775 0ustar0000000000000000Copyright (c) 2015, David Luposchainsky & Herbert Valerio Riedel All rights reserved. Redistribution 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 Herbert Valerio Riedel nor the names of other 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. fail-4.9.0.0/Setup.hs0000644000000000000000000000005612650171571012425 0ustar0000000000000000import Distribution.Simple main = defaultMain fail-4.9.0.0/fail.cabal0000644000000000000000000000203312650171571012665 0ustar0000000000000000name: fail version: 4.9.0.0 synopsis: Forward-compatible MonadFail class homepage: https://prime.haskell.org/wiki/Libraries/Proposals/MonadFail license: BSD3 license-file: LICENSE author: Herbert Valerio Riedel maintainer: libraries@haskell.org category: Development build-type: Simple cabal-version: >=1.10 description: This package contains the "Control.Monad.Fail" module providing the class that became available in for older @base@ package versions. . This package turns into an empty package when used with GHC versions which already provide the "Control.Monad.Fail" module to make way for GHC's own "Control.Monad.Fail" module. library default-language: Haskell2010 if !impl(ghc >= 8.0) exposed-modules: Control.Monad.Fail build-depends: base >=4.3 && <4.9 fail-4.9.0.0/Control/0000755000000000000000000000000012650171571012410 5ustar0000000000000000fail-4.9.0.0/Control/Monad/0000755000000000000000000000000012650171571013446 5ustar0000000000000000fail-4.9.0.0/Control/Monad/Fail.hs0000644000000000000000000000414412650171571014660 0ustar0000000000000000-- | -- Module : Control.Monad.Fail -- Copyright : (C) 2015 David Luposchainsky, -- (C) 2015 Herbert Valerio Riedel -- License : BSD-style (see the file LICENSE) -- -- Maintainer : libraries@haskell.org -- Stability : provisional -- Portability : portable -- -- Transitional module providing the 'MonadFail' class and primitive -- instances. -- -- This module can be imported for defining forward compatible -- 'MonadFail' instances: -- -- @ -- import qualified Control.Monad.Fail as Fail -- -- instance Monad Foo where -- (>>=) = {- ...bind impl... -} -- -- -- Provide legacy 'fail' implementation for when -- -- new-style MonadFail desugaring is not enabled. -- fail = Fail.fail -- -- instance Fail.MonadFail Foo where -- fail = {- ...fail implementation... -} -- @ -- -- See -- for more details. -- -- @since 4.9.0.0 -- module Control.Monad.Fail ( MonadFail(fail) ) where import qualified Prelude as P import Prelude hiding (fail) import Text.ParserCombinators.ReadP import Text.ParserCombinators.ReadPrec -- | When a value is bound in @do@-notation, the pattern on the left -- hand side of @<-@ might not match. In this case, this class -- provides a function to recover. -- -- A 'Monad' without a 'MonadFail' instance may only be used in conjunction -- with pattern that always match, such as newtypes, tuples, data types with -- only a single data constructor, and irrefutable patterns (@~pat@). -- -- Instances of 'MonadFail' should satisfy the following law: @fail s@ should -- be a left zero for '>>=', -- -- @ -- fail s >>= f = fail s -- @ -- -- If your 'Monad' is also 'MonadPlus', a popular definition is -- -- @ -- fail _ = mzero -- @ -- -- @since 4.9.0.0 class Monad m => MonadFail m where fail :: String -> m a -- instances provided by base-4.9 instance MonadFail Maybe where fail _ = Nothing instance MonadFail [] where fail _ = [] instance MonadFail IO where fail = P.fail instance MonadFail ReadPrec where fail = P.fail -- = P (\_ -> fail s) instance MonadFail ReadP where fail = P.fail