diff --git a/CHANGES.markdown b/CHANGES.markdown --- a/CHANGES.markdown +++ b/CHANGES.markdown @@ -1,10 +1,17 @@ -## Changes in 0.8.8.2 [2023.03.07] - - Fix GHC 9.2.1 build error that was accidentally introduced in - `base-orphans-0.8.8`. - -## Changes in 0.8.8.1 [2023.03.05] - - Fix GHC 9.4 build error that was accidentally introduced in - `base-orphans-0.8.8`. +## Changes in 0.9.0 [2023.03.05] + - Adapt to recent changes to `Down` instances: + * The `Bounded` instance for `Down` was changed in `base-4.15.0.0` to swap + the values of `minBound` and `maxBound` for the underlying type. This + change has now been propagated to `base-orphans`. + * The `Enum` instance for `Down` was removed in `base-4.15.0.0`, but a + different version of the instance was added back in `base-4.18.0.0`, where + `succ` and `pred` are swapped. We have changed the backported version of + this instance in `base-orphans` to match the behavior of the instance + added in `base-4.18.0.0`. + * The `Integral` instance for `Down` was removed from `base` entirely in + `base-4.15.0.0`. We have finally removed it from `base-orphans` in this + release, as it actively makes it more difficult to define the + aforementioned `Enum` instance. ## Changes in 0.8.8 [2023.03.05] - Backport new instances from GHC 9.6.1/`base-4.18.0.0`: diff --git a/README.markdown b/README.markdown --- a/README.markdown +++ b/README.markdown @@ -36,7 +36,7 @@ * `Alternative`, `Eq`, `Ord`, `Read`, `Show`, `Foldable`, and `Traversable` instances for `ZipList` * `Applicative` instance for `K1` from `GHC.Generics` * `Applicative`, `Bits`, `Bounded`, `Data`, `Enum`, `Eq1`, `FiniteBits`, - `Floating`, `Foldable`, `Fractional`, `Functor`, `Integral`, `Ix`, `Ord1`, + `Floating`, `Foldable`, `Fractional`, `Functor`, `Ix`, `Ord1`, `Monad`, `MonadFix`, `MonadZip`, `Monoid`, `Num`, `Read`, `Read1`, `Real`, `RealFloat`, `RealFrac`, `Semigroup`, `Show`, `Show1`, `Storable`, and `Traversable` instances for `Down` diff --git a/base-orphans.cabal b/base-orphans.cabal --- a/base-orphans.cabal +++ b/base-orphans.cabal @@ -4,10 +4,10 @@ -- -- see: https://github.com/sol/hpack -- --- hash: 5f8726da7da713fa7b7a95dea492501a6762a25a36aebbd6bb8931e0d0324660 +-- hash: 7aa19d6f2d3a7409ee405d67a21b8edb902103b703a6f241f2b5e8e219f70a87 name: base-orphans -version: 0.8.8.2 +version: 0.9.0 synopsis: Backwards-compatible orphan instances for base description: @base-orphans@ defines orphan instances that mimic instances available in later versions of @base@ to a wider (older) range of compilers. @@ -36,7 +36,7 @@ license-file: LICENSE build-type: Simple tested-with: - GHC == 7.0.4 , GHC == 7.2.2 , GHC == 7.4.2 , GHC == 7.6.3 , GHC == 7.8.4 , GHC == 7.10.3 , GHC == 8.0.2 , GHC == 8.2.2 , GHC == 8.4.4 , GHC == 8.6.5 , GHC == 8.8.4 , GHC == 8.10.7 , GHC == 9.0.2 , GHC == 9.2.1 , GHC == 9.2.7 , GHC == 9.4.4 , GHC == 9.6.1 + GHC == 7.0.4 , GHC == 7.2.2 , GHC == 7.4.2 , GHC == 7.6.3 , GHC == 7.8.4 , GHC == 7.10.3 , GHC == 8.0.2 , GHC == 8.2.2 , GHC == 8.4.4 , GHC == 8.6.5 , GHC == 8.8.4 , GHC == 8.10.7 , GHC == 9.0.2 , GHC == 9.2.7 , GHC == 9.4.4 , GHC == 9.6.1 extra-source-files: CHANGES.markdown README.markdown diff --git a/src/Data/Orphans.hs b/src/Data/Orphans.hs --- a/src/Data/Orphans.hs +++ b/src/Data/Orphans.hs @@ -94,7 +94,7 @@ # endif #endif -#if !(MIN_VERSION_base(4,16,1)) || (MIN_VERSION_base(4,17,0) && !(MIN_VERSION_base(4,18,0))) +#if !(MIN_VERSION_base(4,18,0)) import Data.Orphans.Prelude #endif @@ -1188,12 +1188,14 @@ Kleisli f `mplus` Kleisli g = Kleisli $ \x -> f x `mplus` g x {-# INLINE mplus #-} +-- | Swaps @'minBound'@ and @'maxBound'@ of the underlying type. +instance Bounded a => Bounded (Down a) where + minBound = Down maxBound + maxBound = Down minBound + deriving instance Bits a => Bits (Down a) -deriving instance Bounded a => Bounded (Down a) -deriving instance Enum a => Enum (Down a) deriving instance Floating a => Floating (Down a) deriving instance Fractional a => Fractional (Down a) -deriving instance Integral a => Integral (Down a) deriving instance Ix a => Ix (Down a) deriving instance Real a => Real (Down a) deriving instance RealFrac a => RealFrac (Down a) @@ -1973,6 +1975,26 @@ fmap fun (a, b, c, d, e, f) = (a, b, c, d, e, fun f) instance Functor ((,,,,,,) a b c d e f) where fmap fun (a, b, c, d, e, f, g) = (a, b, c, d, e, f, fun g) + +# if !(MIN_VERSION_base(4,14,0)) || MIN_VERSION_base(4,15,0) +-- | Swaps @'succ'@ and @'pred'@ of the underlying type. +instance (Enum a, Bounded a, Eq a) => Enum (Down a) where + succ = fmap pred + pred = fmap succ + + -- Here we use the fact that 'comparing (complement @Int)' behaves + -- as an order-swapping `compare @Int`. + fromEnum (Down x) = complement $ fromEnum x + toEnum = Down . toEnum . complement + + enumFrom (Down x) + | x == minBound + = [Down x] -- We can't rely on 'enumFromThen _ (pred @a minBound)` behaving nicely, + -- since 'enumFromThen _' might be strict and 'pred minBound' might throw + | otherwise + = coerce $ enumFromThen x (pred x) + enumFromThen (Down x) (Down y) = coerce $ enumFromThen x y +# endif # if MIN_VERSION_base(4,17,0) instance (Generic1 f, Eq (Rep1 f a)) => Eq (Generically1 f a) where