diff --git a/.ghci b/.ghci new file mode 100644 --- /dev/null +++ b/.ghci @@ -0,0 +1,1 @@ +:set -isrc -idist/build/autogen -optP-include -optPdist/build/autogen/cabal_macros.h diff --git a/.gitignore b/.gitignore new file mode 100644 --- /dev/null +++ b/.gitignore @@ -0,0 +1,15 @@ +*# +*.hi +*.o +*~ +.*.swo +.*.swp +.swp +.DS_Store +TAGS +_darcs +dist +docs +tags +wiki +wip diff --git a/.vim.custom b/.vim.custom new file mode 100644 --- /dev/null +++ b/.vim.custom @@ -0,0 +1,31 @@ +" Add the following to your .vimrc to automatically load this on startup + +" if filereadable(".vim.custom") +" so .vim.custom +" endif + +function StripTrailingWhitespace() + let myline=line(".") + let mycolumn = col(".") + silent %s/ *$// + call cursor(myline, mycolumn) +endfunction + +" enable syntax highlighting +syntax on + +" search for the tags file anywhere between here and / +set tags=TAGS;/ + +" highlight tabs and trailing spaces +set listchars=tab:‗‗,trail:‗ +set list + +" f2 runs hasktags +map :exec ":!hasktags -x -c --ignore src" + +" strip trailing whitespace before saving +" au BufWritePre *.hs,*.markdown silent! cal StripTrailingWhitespace() + +" rebuild hasktags after saving +au BufWritePost *.hs silent! :exec ":!hasktags -x -c --ignore src" diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown --- a/CHANGELOG.markdown +++ b/CHANGELOG.markdown @@ -1,3 +1,9 @@ +0.6 +--- +* `instance Exception Void` +* `instance Generic Void` +* `instance Hashable Void` + 0.5.12 ------ * Fixed compatibility with GHC 7.2 (#6) diff --git a/Data/Void.hs b/Data/Void.hs deleted file mode 100644 --- a/Data/Void.hs +++ /dev/null @@ -1,76 +0,0 @@ -{-# LANGUAGE CPP #-} ------------------------------------------------------------------------------ --- | --- Module : Data.Void --- Copyright : (C) 2008-2011 Edward Kmett --- License : BSD-style (see the file LICENSE) --- --- Maintainer : Edward Kmett --- Stability : provisional --- Portability : portable --- ----------------------------------------------------------------------------- -module Data.Void - ( Void - , absurd - , vacuous - , vacuousM - ) where - -import Data.Ix -import Control.Monad (liftM) -import Data.Semigroup (Semigroup(..)) - -#ifdef LANGUAGE_DeriveDataTypeable -import Data.Data -#endif - --- | A logically uninhabited data type. -#if __GLASGOW_HASKELL__ < 700 -data Void = Void !Void -#else -newtype Void = Void Void -#endif -#ifdef LANGUAGE_DeriveDataTypeable - deriving (Data, Typeable) -#endif - -instance Eq Void where - _ == _ = True - -instance Ord Void where - compare _ _ = EQ - -instance Show Void where - showsPrec _ = absurd - --- | Reading a 'Void' value is always a parse error, considering 'Void' as --- a data type with no constructors. -instance Read Void where - readsPrec _ _ = [] - --- | Since 'Void' values logically don't exist, this witnesses the logical --- reasoning tool of \"ex falso quodlibet\". -absurd :: Void -> a -absurd a = a `seq` spin a where - spin (Void b) = spin b - --- | If 'Void' is uninhabited then any 'Functor' that holds only values of type 'Void' --- is holding no values. -vacuous :: Functor f => f Void -> f a -vacuous = fmap absurd - --- | If 'Void' is uninhabited then any 'Monad' that holds values of type 'Void' --- is holding no values. -vacuousM :: Monad m => m Void -> m a -vacuousM = liftM absurd - -instance Semigroup Void where - a <> _ = a - times1p _ a = a - -instance Ix Void where - range _ = [] - index _ = absurd - inRange _ = absurd - rangeSize _ = 0 diff --git a/Data/Void/Unsafe.hs b/Data/Void/Unsafe.hs deleted file mode 100644 --- a/Data/Void/Unsafe.hs +++ /dev/null @@ -1,48 +0,0 @@ -{-# LANGUAGE CPP #-} -#if !defined(SAFE) && defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 704 -#define UNSAFE -{-# LANGUAGE Unsafe #-} -#endif ------------------------------------------------------------------------------ --- | --- Module : Data.Void.Unsafe --- Copyright : (C) 2008-2012 Edward Kmett --- License : BSD-style (see the file LICENSE) --- --- Maintainer : Edward Kmett --- Stability : provisional --- Portability : portable --- ----------------------------------------------------------------------------- -module Data.Void.Unsafe - ( unsafeVacuous - , unsafeVacuousM - ) where - -import Data.Void - -#ifdef UNSAFE -import Unsafe.Coerce -#endif - --- | If 'Void' is uninhabited than any 'Functor' that holds only values of the type 'Void' --- is holding no values. --- --- This is only safe for valid functors that do not perform GADT-like analysis on the argument. -unsafeVacuous :: Functor f => f Void -> f a -#ifdef UNSAFE -unsafeVacuous = unsafeCoerce -#else -unsafeVacuous = fmap absurd -#endif - --- | If 'Void' is uninhabited then any 'Monad' that holds values of type 'Void' --- is holding no values. --- --- This is only safe for valid monads that do not perform GADT-like analysis on the argument. -unsafeVacuousM :: Monad m => m Void -> m a -#ifdef UNSAFE -unsafeVacuousM = unsafeCoerce -#else -unsafeVacuousM m = m >>= return . absurd -#endif diff --git a/LICENSE b/LICENSE --- a/LICENSE +++ b/LICENSE @@ -1,4 +1,4 @@ -Copyright 2011 Edward Kmett +Copyright 2013 Edward Kmett All rights reserved. diff --git a/src/Data/Void.hs b/src/Data/Void.hs new file mode 100644 --- /dev/null +++ b/src/Data/Void.hs @@ -0,0 +1,108 @@ +{-# LANGUAGE CPP #-} + +#ifdef LANGUAGE_DeriveDataTypeable +{-# LANGUAGE DeriveDataTypeable #-} +#endif + +#ifdef LANGUAGE_DeriveGeneric +{-# LANGUAGE DeriveGeneric #-} +{-# LANGUAGE StandaloneDeriving #-} +#endif + +#ifndef MIN_VERSION_base +#define MIN_VERSION_base(x,y,z) 1 +#endif +----------------------------------------------------------------------------- +-- | +-- Copyright : (C) 2008-2013 Edward Kmett +-- License : BSD-style (see the file LICENSE) +-- +-- Maintainer : Edward Kmett +-- Stability : provisional +-- Portability : portable +-- +---------------------------------------------------------------------------- +module Data.Void + ( Void + , absurd + , vacuous + , vacuousM + ) where + +import Control.Monad (liftM) +import Data.Ix +import Data.Hashable +import Data.Semigroup (Semigroup(..)) + +#ifdef LANGUAGE_DeriveDataTypeable +import Data.Data +#endif + +#ifdef LANGUAGE_DeriveGeneric +import GHC.Generics +#endif + +#if MIN_VERSION_base(4,0,0) +import Control.Exception +#endif + +-- | A logically uninhabited data type. +#if __GLASGOW_HASKELL__ < 700 +data Void = Void !Void +#else +newtype Void = Void Void +#endif +#ifdef LANGUAGE_DeriveDataTypeable + deriving (Data, Typeable) +#endif + +#ifdef LANGUAGE_DeriveGeneric +deriving instance Generic Void +#endif + +instance Eq Void where + _ == _ = True + +instance Hashable Void where + hashWithSalt _ = absurd + +instance Ord Void where + compare _ _ = EQ + +instance Show Void where + showsPrec _ = absurd + +-- | Reading a 'Void' value is always a parse error, considering 'Void' as +-- a data type with no constructors. +instance Read Void where + readsPrec _ _ = [] + +-- | Since 'Void' values logically don't exist, this witnesses the logical +-- reasoning tool of \"ex falso quodlibet\". +absurd :: Void -> a +absurd a = a `seq` spin a where + spin (Void b) = spin b + +-- | If 'Void' is uninhabited then any 'Functor' that holds only values of type 'Void' +-- is holding no values. +vacuous :: Functor f => f Void -> f a +vacuous = fmap absurd + +-- | If 'Void' is uninhabited then any 'Monad' that holds values of type 'Void' +-- is holding no values. +vacuousM :: Monad m => m Void -> m a +vacuousM = liftM absurd + +instance Semigroup Void where + a <> _ = a + times1p _ a = a + +instance Ix Void where + range _ = [] + index _ = absurd + inRange _ = absurd + rangeSize _ = 0 + +#if MIN_VERSION_base(4,0,0) +instance Exception Void +#endif diff --git a/src/Data/Void/Unsafe.hs b/src/Data/Void/Unsafe.hs new file mode 100644 --- /dev/null +++ b/src/Data/Void/Unsafe.hs @@ -0,0 +1,47 @@ +{-# LANGUAGE CPP #-} +#if !defined(SAFE) && defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 704 +#define UNSAFE +{-# LANGUAGE Unsafe #-} +#endif +----------------------------------------------------------------------------- +-- | +-- Copyright : (C) 2008-2013 Edward Kmett +-- License : BSD-style (see the file LICENSE) +-- +-- Maintainer : Edward Kmett +-- Stability : provisional +-- Portability : portable +-- +---------------------------------------------------------------------------- +module Data.Void.Unsafe + ( unsafeVacuous + , unsafeVacuousM + ) where + +import Data.Void + +#ifdef UNSAFE +import Unsafe.Coerce +#endif + +-- | If 'Void' is uninhabited than any 'Functor' that holds only values of the type 'Void' +-- is holding no values. +-- +-- This is only safe for valid functors that do not perform GADT-like analysis on the argument. +unsafeVacuous :: Functor f => f Void -> f a +#ifdef UNSAFE +unsafeVacuous = unsafeCoerce +#else +unsafeVacuous = fmap absurd +#endif + +-- | If 'Void' is uninhabited then any 'Monad' that holds values of type 'Void' +-- is holding no values. +-- +-- This is only safe for valid monads that do not perform GADT-like analysis on the argument. +unsafeVacuousM :: Monad m => m Void -> m a +#ifdef UNSAFE +unsafeVacuousM = unsafeCoerce +#else +unsafeVacuousM m = m >>= return . absurd +#endif diff --git a/void.cabal b/void.cabal --- a/void.cabal +++ b/void.cabal @@ -1,6 +1,6 @@ name: void category: Data Structures -version: 0.5.12 +version: 0.6 license: BSD3 cabal-version: >= 1.6 license-file: LICENSE @@ -9,12 +9,18 @@ stability: portable homepage: http://github.com/ekmett/void bug-reports: http://github.com/ekmett/void/issues -copyright: Copyright (C) 2008-2012 Edward A. Kmett +copyright: Copyright (C) 2008-2013 Edward A. Kmett synopsis: A Haskell 98 logically uninhabited data type description: A Haskell 98 logically uninhabited data type, used to indicate that a given term should not exist. build-type: Simple -extra-source-files: .travis.yml CHANGELOG.markdown README.markdown +extra-source-files: + .ghci + .gitignore + .travis.yml + .vim.custom + CHANGELOG.markdown + README.markdown source-repository head type: git @@ -25,12 +31,14 @@ default: False library + hs-source-dirs: src exposed-modules: Data.Void Data.Void.Unsafe build-depends: base >= 3 && < 10, + hashable >= 1.1, semigroups >= 0.8.2 ghc-options: -Wall @@ -39,5 +47,11 @@ cpp-options: -DSAFE if impl(ghc) - extensions: DeriveDataTypeable + other-extensions: DeriveDataTypeable cpp-options: -DLANGUAGE_DeriveDataTypeable + + if impl(ghc >= 7.2) + other-extensions: StandaloneDeriving + -- other-extensions: DeriveGeneric isn't known to cabal yet + cpp-options: -DLANGUAGE_DeriveGeneric + build-depends: ghc-prim