Replace hand-written Bounded instances with derived ones

Summary:
The spiritual successor to D2291, since deriving `Bounded` instances
in `GHC.Enum` wasn't possible prior to changes made in that Diff.

This Diff finds every manually implemented `Bounded` instance in `base` that is
completely equivalent to the derived instances, and replaces it.

Reviewers: bgamari, goldfire, austin, hvr

Reviewed By: austin, hvr

Subscribers: thomie, rwbarton

Differential Revision: https://phabricator.haskell.org/D2301

1 files changed, 50 insertions, 100 deletions

diff --git a/libraries/base/GHC/Enum.hs b/libraries/base/GHC/Enum.hs
index 729b801dcf..c0e2f5a783 100644
--- a/libraries/base/GHC/Enum.hs
+++ b/libraries/base/GHC/Enum.hs
@@ -1,5 +1,9 @@
+{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE MagicHash #-}
+{-# LANGUAGE NoImplicitPrelude #-}
+{-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE Trustworthy #-}
-{-# LANGUAGE CPP, NoImplicitPrelude, BangPatterns, MagicHash #-}
 {-# OPTIONS_HADDOCK hide #-}
 
 -----------------------------------------------------------------------------
@@ -150,10 +154,7 @@ predError inst_ty =
 -- Tuples
 ------------------------------------------------------------------------
 
-instance Bounded () where
-    minBound = ()
-    maxBound = ()
-
+deriving instance Bounded ()
 instance Enum () where
     succ _      = errorWithoutStackTrace "Prelude.Enum.().succ: bad argument"
     pred _      = errorWithoutStackTrace "Prelude.Enum.().pred: bad argument"
@@ -168,102 +169,54 @@ instance Enum () where
     enumFromThenTo () () () = let many = ():many in many
 
 -- Report requires instances up to 15
-instance (Bounded a, Bounded b) => Bounded (a,b) where
-   minBound = (minBound, minBound)
-   maxBound = (maxBound, maxBound)
-
-instance (Bounded a, Bounded b, Bounded c) => Bounded (a,b,c) where
-   minBound = (minBound, minBound, minBound)
-   maxBound = (maxBound, maxBound, maxBound)
-
-instance (Bounded a, Bounded b, Bounded c, Bounded d) => Bounded (a,b,c,d) where
-   minBound = (minBound, minBound, minBound, minBound)
-   maxBound = (maxBound, maxBound, maxBound, maxBound)
-
-instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e) => Bounded (a,b,c,d,e) where
-   minBound = (minBound, minBound, minBound, minBound, minBound)
-   maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound)
-
-instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f)
-        => Bounded (a,b,c,d,e,f) where
-   minBound = (minBound, minBound, minBound, minBound, minBound, minBound)
-   maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound)
-
-instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g)
-        => Bounded (a,b,c,d,e,f,g) where
-   minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound)
-   maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound)
-
-instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
-          Bounded h)
-        => Bounded (a,b,c,d,e,f,g,h) where
-   minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound)
-   maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound)
-
-instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
-          Bounded h, Bounded i)
-        => Bounded (a,b,c,d,e,f,g,h,i) where
-   minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
-               minBound)
-   maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
-               maxBound)
-
-instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
-          Bounded h, Bounded i, Bounded j)
-        => Bounded (a,b,c,d,e,f,g,h,i,j) where
-   minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
-               minBound, minBound)
-   maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
-               maxBound, maxBound)
-
-instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
-          Bounded h, Bounded i, Bounded j, Bounded k)
-        => Bounded (a,b,c,d,e,f,g,h,i,j,k) where
-   minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
-               minBound, minBound, minBound)
-   maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
-               maxBound, maxBound, maxBound)
-
-instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
-          Bounded h, Bounded i, Bounded j, Bounded k, Bounded l)
-        => Bounded (a,b,c,d,e,f,g,h,i,j,k,l) where
-   minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
-               minBound, minBound, minBound, minBound)
-   maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
-               maxBound, maxBound, maxBound, maxBound)
-
-instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
-          Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m)
-        => Bounded (a,b,c,d,e,f,g,h,i,j,k,l,m) where
-   minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
-               minBound, minBound, minBound, minBound, minBound)
-   maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
-               maxBound, maxBound, maxBound, maxBound, maxBound)
-
-instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
-          Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n)
-        => Bounded (a,b,c,d,e,f,g,h,i,j,k,l,m,n) where
-   minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
-               minBound, minBound, minBound, minBound, minBound, minBound)
-   maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
-               maxBound, maxBound, maxBound, maxBound, maxBound, maxBound)
-
-instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g,
-          Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n, Bounded o)
-        => Bounded (a,b,c,d,e,f,g,h,i,j,k,l,m,n,o) where
-   minBound = (minBound, minBound, minBound, minBound, minBound, minBound, minBound, minBound,
-               minBound, minBound, minBound, minBound, minBound, minBound, minBound)
-   maxBound = (maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound,
-               maxBound, maxBound, maxBound, maxBound, maxBound, maxBound, maxBound)
+deriving instance (Bounded a, Bounded b)
+        => Bounded (a,b)
+deriving instance (Bounded a, Bounded b, Bounded c)
+        => Bounded (a,b,c)
+deriving instance (Bounded a, Bounded b, Bounded c, Bounded d)
+        => Bounded (a,b,c,d)
+deriving instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e)
+        => Bounded (a,b,c,d,e)
+deriving instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e,
+          Bounded f)
+        => Bounded (a,b,c,d,e,f)
+deriving instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e,
+          Bounded f, Bounded g)
+        => Bounded (a,b,c,d,e,f,g)
+deriving instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e,
+          Bounded f, Bounded g, Bounded h)
+        => Bounded (a,b,c,d,e,f,g,h)
+deriving instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e,
+          Bounded f, Bounded g, Bounded h, Bounded i)
+        => Bounded (a,b,c,d,e,f,g,h,i)
+deriving instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e,
+          Bounded f, Bounded g, Bounded h, Bounded i, Bounded j)
+        => Bounded (a,b,c,d,e,f,g,h,i,j)
+deriving instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e,
+          Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k)
+        => Bounded (a,b,c,d,e,f,g,h,i,j,k)
+deriving instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e,
+          Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k,
+          Bounded l)
+        => Bounded (a,b,c,d,e,f,g,h,i,j,k,l)
+deriving instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e,
+          Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k,
+          Bounded l, Bounded m)
+        => Bounded (a,b,c,d,e,f,g,h,i,j,k,l,m)
+deriving instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e,
+          Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k,
+          Bounded l, Bounded m, Bounded n)
+        => Bounded (a,b,c,d,e,f,g,h,i,j,k,l,m,n)
+deriving instance (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e,
+          Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k,
+          Bounded l, Bounded m, Bounded n, Bounded o)
+        => Bounded (a,b,c,d,e,f,g,h,i,j,k,l,m,n,o)
 
 ------------------------------------------------------------------------
 -- Bool
 ------------------------------------------------------------------------
 
-instance Bounded Bool where
-  minBound = False
-  maxBound = True
-
+deriving instance Bounded Bool
 instance Enum Bool where
   succ False = True
   succ True  = errorWithoutStackTrace "Prelude.Enum.Bool.succ: bad argument"
@@ -286,10 +239,7 @@ instance Enum Bool where
 -- Ordering
 ------------------------------------------------------------------------
 
-instance Bounded Ordering where
-  minBound = LT
-  maxBound = GT
-
+deriving instance Bounded Ordering
 instance Enum Ordering where
   succ LT = EQ
   succ EQ = GT