libraries/base/Control/Monad/Fix.hs

@@ -156,4 +156,3 @@ instance (MonadFix f, MonadFix g) => MonadFix (f :*: g) where
 -- | @since 4.12.0.0
 instance MonadFix Down where
     mfix f = Down (fix (getDown . f))
-      where getDown (Down x) = x

libraries/base/Data/Ord.hs

@@ -7,7 +7,7 @@
 -- Module      :  Data.Ord
 -- Copyright   :  (c) The University of Glasgow 2005
 -- License     :  BSD-style (see the file libraries/base/LICENSE)
--- 
+--
 -- Maintainer  :  libraries@haskell.org
 -- Stability   :  stable
 -- Portability :  portable
@@ -23,12 +23,18 @@ module Data.Ord (
    comparing,
  ) where
 
+import Data.Bits (Bits, FiniteBits)
+import Foreign.Storable (Storable)
+import GHC.Arr (Ix)
 import GHC.Base
-import GHC.Show
-import GHC.Read
+import GHC.Enum (Bounded, Enum)
+import GHC.Float (Floating, RealFloat)
 import GHC.Num
+import GHC.Read
+import GHC.Real (Fractional, Integral, Real, RealFrac)
+import GHC.Show
 
--- | 
+-- |
 -- > comparing p x y = compare (p x) (p y)
 --
 -- Useful combinator for use in conjunction with the @xxxBy@ family
@@ -46,16 +52,44 @@ comparing p x y = compare (p x) (p y)
 -- as in: @then sortWith by 'Down' x@
 --
 -- @since 4.6.0.0
-newtype Down a = Down a
+newtype Down a = Down
+    { getDown :: a -- ^ @since 4.14.0.0
+    }
     deriving
       ( Eq        -- ^ @since 4.6.0.0
-      , Show      -- ^ @since 4.7.0.0
-      , Read      -- ^ @since 4.7.0.0
       , Num       -- ^ @since 4.11.0.0
       , Semigroup -- ^ @since 4.11.0.0
       , Monoid    -- ^ @since 4.11.0.0
+      , Bits       -- ^ @since 4.14.0.0
+      , Bounded    -- ^ @since 4.14.0.0
+      , Enum       -- ^ @since 4.14.0.0
+      , FiniteBits -- ^ @since 4.14.0.0
+      , Floating   -- ^ @since 4.14.0.0
+      , Fractional -- ^ @since 4.14.0.0
+      , Integral   -- ^ @since 4.14.0.0
+      , Ix         -- ^ @since 4.14.0.0
+      , Real       -- ^ @since 4.14.0.0
+      , RealFrac   -- ^ @since 4.14.0.0
+      , RealFloat  -- ^ @since 4.14.0.0
+      , Storable   -- ^ @since 4.14.0.0
       )
 
+-- | This instance would be equivalent to the derived instances of the
+-- 'Down' newtype if the 'getDown' field were removed
+--
+-- @since 4.7.0.0
+instance (Read a) => Read (Down a) where
+    readsPrec d = readParen (d > 10) $ \ r ->
+        [(Down x,t) | ("Down",s) <- lex r, (x,t) <- readsPrec 11 s]
+
+-- | This instance would be equivalent to the derived instances of the
+-- 'Down' newtype if the 'getDown' field were removed
+--
+-- @since 4.7.0.0
+instance (Show a) => Show (Down a) where
+    showsPrec d (Down x) = showParen (d > 10) $
+        showString "Down " . showsPrec 11 x
+
 -- | @since 4.6.0.0
 instance Ord a => Ord (Down a) where
     compare (Down x) (Down y) = y `compare` x

libraries/base/changelog.md

@@ -5,6 +5,12 @@
 
   * Add a `TestEquality` instance for the `Compose` newtype.
 
+  * `Data.Ord.Down` now has a field name, `getDown`
+
+  * Add `Bits`, `Bounded`, `Enum`, `FiniteBits`, `Floating`, `Fractional`,
+    `Integral`, `Ix`, `Real`, `RealFrac`, `RealFloat` and `Storable` instances
+    to `Data.Ord.Down`.
+
   * Fix the `integer-gmp` variant of `isValidNatural`: Previously it would fail
     to detect values `<= maxBound::Word` that were incorrectly encoded using
     the `NatJ#` constructor.