Drop support for GHC 8.0 (#354)

This allows us to remove a good amount of CPP and hacks.

Author: sjakobi

.github/workflows/haskell-ci.yml

@@ -8,9 +8,9 @@
 #
 # For more information, see https://github.com/haskell-CI/haskell-ci
 #
-# version: 0.13.20211116
+# version: 0.14.1
 #
-# REGENDATA ("0.13.20211116",["github","unordered-containers.cabal"])
+# REGENDATA ("0.14.1",["github","unordered-containers.cabal"])
 #
 name: Haskell-CI
 on:
@@ -37,10 +37,10 @@ jobs:
             compilerVersion: 9.2.1
             setup-method: ghcup
             allow-failure: false
-          - compiler: ghc-9.0.1
+          - compiler: ghc-9.0.2
             compilerKind: ghc
-            compilerVersion: 9.0.1
-            setup-method: hvr-ppa
+            compilerVersion: 9.0.2
+            setup-method: ghcup
             allow-failure: false
           - compiler: ghc-8.10.7
             compilerKind: ghc
@@ -67,11 +67,6 @@ jobs:
             compilerVersion: 8.2.2
             setup-method: hvr-ppa
             allow-failure: false
-          - compiler: ghc-8.0.2
-            compilerKind: ghc
-            compilerVersion: 8.0.2
-            setup-method: hvr-ppa
-            allow-failure: false
       fail-fast: false
     steps:
       - name: apt
@@ -198,8 +193,8 @@ jobs:
           touch cabal.project
           touch cabal.project.local
           echo "packages: ${PKGDIR_unordered_containers}" >> cabal.project
-          if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then echo "package unordered-containers" >> cabal.project ; fi
-          if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then echo "    ghc-options: -Werror=missing-methods" >> cabal.project ; fi
+          echo "package unordered-containers" >> cabal.project
+          echo "    ghc-options: -Werror=missing-methods" >> cabal.project
           cat >> cabal.project <<EOF
           EOF
           $HCPKG list --simple-output --names-only | perl -ne 'for (split /\s+/) { print "constraints: $_ installed\n" unless /^(binary|containers|unordered-containers)$/; }' >> cabal.project.local

Data/HashMap/Internal.hs

@@ -10,10 +10,8 @@
 {-# LANGUAGE TemplateHaskellQuotes #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE UnboxedTuples #-}
-#if __GLASGOW_HASKELL__ >= 802
 {-# LANGUAGE TypeInType #-}
 {-# LANGUAGE UnboxedSums #-}
-#endif
 {-# OPTIONS_GHC -fno-full-laziness -funbox-strict-fields #-}
 {-# OPTIONS_HADDOCK not-home #-}
 
@@ -148,9 +146,7 @@ import Control.Monad.ST (ST, runST)
 import Data.Bits ((.&.), (.|.), complement, popCount, unsafeShiftL, unsafeShiftR)
 import Data.Data
 import qualified Data.Foldable as Foldable
-#if MIN_VERSION_base(4,10,0)
 import Data.Bifoldable
-#endif
 import qualified Data.List as L
 import GHC.Exts ((==#), build, reallyUnsafePtrEquality#, inline)
 import Prelude hiding (filter, foldl, foldr, lookup, map, null, pred)
@@ -171,13 +167,9 @@ import GHC.Stack
 import qualified Data.Hashable.Lifted as H
 #endif
 
-#if MIN_VERSION_deepseq(1,4,3)
 import qualified Control.DeepSeq as NF
-#endif
 
-#if __GLASGOW_HASKELL__ >= 802
 import GHC.Exts (TYPE, Int (..), Int#)
-#endif
 
 import Data.Functor.Identity (Identity (..))
 import Control.Applicative (Const (..))
@@ -205,15 +197,13 @@ instance (TH.Lift k, TH.Lift v) => TH.Lift (Leaf k v) where
   lift (L k v) = [| L k $! v |]
 #endif
 
-#if MIN_VERSION_deepseq(1,4,3)
 -- | @since 0.2.14.0
 instance NFData k => NF.NFData1 (Leaf k) where
     liftRnf rnf2 = NF.liftRnf2 rnf rnf2
 
 -- | @since 0.2.14.0
 instance NF.NFData2 Leaf where
     liftRnf2 rnf1 rnf2 (L k v) = rnf1 k `seq` rnf2 v
-#endif
 
 -- Invariant: The length of the 1st argument to 'Full' is
 -- 2^bitsPerSubkey
@@ -239,7 +229,6 @@ instance (NFData k, NFData v) => NFData (HashMap k v) where
     rnf (Full ary)            = rnf ary
     rnf (Collision _ ary)     = rnf ary
 
-#if MIN_VERSION_deepseq(1,4,3)
 -- | @since 0.2.14.0
 instance NFData k => NF.NFData1 (HashMap k) where
     liftRnf rnf2 = NF.liftRnf2 rnf rnf2
@@ -251,7 +240,6 @@ instance NF.NFData2 HashMap where
     liftRnf2 rnf1 rnf2 (Leaf _ l)            = NF.liftRnf2 rnf1 rnf2 l
     liftRnf2 rnf1 rnf2 (Full ary)            = NF.liftRnf (NF.liftRnf2 rnf1 rnf2) ary
     liftRnf2 rnf1 rnf2 (Collision _ ary)     = NF.liftRnf (NF.liftRnf2 rnf1 rnf2) ary
-#endif
 
 instance Functor (HashMap k) where
     fmap = map
@@ -272,7 +260,6 @@ instance Foldable.Foldable (HashMap k) where
     length = size
     {-# INLINE length #-}
 
-#if MIN_VERSION_base(4,10,0)
 -- | @since 0.2.11
 instance Bifoldable HashMap where
     bifoldMap f g = foldMapWithKey (\ k v -> f k `mappend` g v)
@@ -281,7 +268,6 @@ instance Bifoldable HashMap where
     {-# INLINE bifoldr #-}
     bifoldl f g = foldlWithKey (\ acc k v -> (acc `f` k) `g` v)
     {-# INLINE bifoldl #-}
-#endif
 
 -- | '<>' = 'union'
 --
@@ -606,7 +592,6 @@ member k m = case lookup k m of
 -- | /O(log n)/ Return the value to which the specified key is mapped,
 -- or 'Nothing' if this map contains no mapping for the key.
 lookup :: (Eq k, Hashable k) => k -> HashMap k v -> Maybe v
-#if __GLASGOW_HASKELL__ >= 802
 -- GHC does not yet perform a worker-wrapper transformation on
 -- unboxed sums automatically. That seems likely to happen at some
 -- point (possibly as early as GHC 8.6) but for now we do it manually.
@@ -619,16 +604,9 @@ lookup# :: (Eq k, Hashable k) => k -> HashMap k v -> (# (# #) | v #)
 lookup# k m = lookupCont (\_ -> (# (# #) | #)) (\v _i -> (# | v #)) (hash k) k 0 m
 {-# INLINABLE lookup# #-}
 
-#else
-
-lookup k m = lookupCont (\_ -> Nothing) (\v _i -> Just v) (hash k) k 0 m
-{-# INLINABLE lookup #-}
-#endif
-
 -- | lookup' is a version of lookup that takes the hash separately.
 -- It is used to implement alterF.
 lookup' :: Eq k => Hash -> k -> HashMap k v -> Maybe v
-#if __GLASGOW_HASKELL__ >= 802
 -- GHC does not yet perform a worker-wrapper transformation on
 -- unboxed sums automatically. That seems likely to happen at some
 -- point (possibly as early as GHC 8.6) but for now we do it manually.
@@ -639,10 +617,6 @@ lookup' h k m = case lookupRecordCollision# h k m of
   (# (# #) | #) -> Nothing
   (# | (# a, _i #) #) -> Just a
 {-# INLINE lookup' #-}
-#else
-lookup' h k m = lookupCont (\_ -> Nothing) (\v _i -> Just v) h k 0 m
-{-# INLINABLE lookup' #-}
-#endif
 
 -- The result of a lookup, keeping track of if a hash collision occured.
 -- If a collision did not occur then it will have the Int value (-1).
@@ -662,7 +636,6 @@ data LookupRes a = Absent | Present a !Int
 --   Key in map, no collision => Present v (-1)
 --   Key in map, collision    => Present v position
 lookupRecordCollision :: Eq k => Hash -> k -> HashMap k v -> LookupRes v
-#if __GLASGOW_HASKELL__ >= 802
 lookupRecordCollision h k m = case lookupRecordCollision# h k m of
   (# (# #) | #) -> Absent
   (# | (# a, i #) #) -> Present a (I# i) -- GHC will eliminate the I#
@@ -679,12 +652,6 @@ lookupRecordCollision# h k m =
 -- INLINABLE to specialize to the Eq instance.
 {-# INLINABLE lookupRecordCollision# #-}
 
-#else /* GHC < 8.2 so there are no unboxed sums */
-
-lookupRecordCollision h k m = lookupCont (\_ -> Absent) Present h k 0 m
-{-# INLINABLE lookupRecordCollision #-}
-#endif
-
 -- A two-continuation version of lookupRecordCollision. This lets us
 -- share source code between lookup and lookupRecordCollision without
 -- risking any performance degradation.
@@ -698,11 +665,7 @@ lookupRecordCollision h k m = lookupCont (\_ -> Absent) Present h k 0 m
 -- keys at the top-level of a hashmap, the offset should be 0. When looking up
 -- keys at level @n@ of a hashmap, the offset should be @n * bitsPerSubkey@.
 lookupCont ::
-#if __GLASGOW_HASKELL__ >= 802
   forall rep (r :: TYPE rep) k v.
-#else
-  forall r k v.
-#endif
      Eq k
   => ((# #) -> r)    -- Absent continuation
   -> (v -> Int -> r) -- Present continuation
@@ -2155,11 +2118,7 @@ fromListWithKey f = L.foldl' (\ m (k, v) -> unsafeInsertWithKey f k v m) empty
 -- | /O(n)/ Look up the value associated with the given key in an
 -- array.
 lookupInArrayCont ::
-#if __GLASGOW_HASKELL__ >= 802
   forall rep (r :: TYPE rep) k v.
-#else
-  forall r k v.
-#endif
   Eq k => ((# #) -> r) -> (v -> Int -> r) -> k -> A.Array (Leaf k v) -> r
 lookupInArrayCont absent present k0 ary0 = go k0 ary0 0 (A.length ary0)
   where

Data/HashMap/Internal/Array.hs

@@ -92,9 +92,7 @@ import qualified Language.Haskell.TH.Syntax as TH
 import qualified Prelude
 #endif
 
-#if MIN_VERSION_deepseq(1,4,3)
 import qualified Control.DeepSeq as NF
-#endif
 
 import Control.Monad ((>=>))
 
@@ -173,7 +171,6 @@ rnfArray ary0 = go ary0 n0 0
 -- relevant rnf is strict, or in case it actually isn't.
 {-# INLINE rnfArray #-}
 
-#if MIN_VERSION_deepseq(1,4,3)
 -- | @since 0.2.14.0
 instance NF.NFData1 Array where
     liftRnf = liftRnfArray
@@ -187,7 +184,6 @@ liftRnfArray rnf0 ary0 = go ary0 n0 0
         | (# x #) <- index# ary i
         = rnf0 x `seq` go ary n (i+1)
 {-# INLINE liftRnfArray #-}
-#endif
 
 -- | Create a new mutable array of specified size, in the specified
 -- state thread, with each element containing the specified initial

Data/HashSet/Internal.hs

@@ -110,9 +110,7 @@ import Text.Read
 import qualified Data.Hashable.Lifted as H
 #endif
 
-#if MIN_VERSION_deepseq(1,4,3)
 import qualified Control.DeepSeq as NF
-#endif
 import qualified Language.Haskell.TH.Syntax as TH
 
 -- | A set of values.  A set cannot contain duplicate values.
@@ -129,11 +127,9 @@ instance (NFData a) => NFData (HashSet a) where
     rnf = rnf . asMap
     {-# INLINE rnf #-}
 
-#if MIN_VERSION_deepseq(1,4,3)
 -- | @since 0.2.14.0
 instance NF.NFData1 HashSet where
     liftRnf rnf1 = NF.liftRnf2 rnf1 rnf . asMap
-#endif
 
 -- | Note that, in the presence of hash collisions, equal @HashSet@s may
 -- behave differently, i.e. substitutivity may be violated:

tests/Properties/HashMapLazy.hs

@@ -12,9 +12,7 @@ module Properties.HashMapLazy (tests) where
 
 import Control.Monad ( guard )
 import qualified Data.Foldable as Foldable
-#if MIN_VERSION_base(4,10,0)
 import Data.Bifoldable
-#endif
 import Data.Function (on)
 import Data.Hashable (Hashable(hashWithSalt))
 import qualified Data.List as L
@@ -337,7 +335,6 @@ pFoldr = (L.sort . M.foldr (:) []) `eq` (L.sort . HM.foldr (:) [])
 pFoldl :: [(Int, Int)] -> Bool
 pFoldl = (L.sort . M.foldl (flip (:)) []) `eq` (L.sort . HM.foldl (flip (:)) [])
 
-#if MIN_VERSION_base(4,10,0)
 pBifoldMap :: [(Int, Int)] -> Bool
 pBifoldMap xs = concatMap f (HM.toList m) == bifoldMap (:[]) (:[]) m
   where f (k, v) = [k, v]
@@ -352,7 +349,6 @@ pBifoldl :: [(Int, Int)] -> Bool
 pBifoldl xs = reverse (concatMap f $ HM.toList m) == bifoldl (flip (:)) (flip (:)) [] m
   where f (k, v) = [k, v]
         m = HM.fromList xs
-#endif
 
 pFoldrWithKey :: [(Int, Int)] -> Bool
 pFoldrWithKey = (sortByKey . M.foldrWithKey f []) `eq`
@@ -514,11 +510,9 @@ tests =
     , testGroup "folds"
       [ testProperty "foldr" pFoldr
       , testProperty "foldl" pFoldl
-#if MIN_VERSION_base(4,10,0)
       , testProperty "bifoldMap" pBifoldMap
       , testProperty "bifoldr" pBifoldr
       , testProperty "bifoldl" pBifoldl
-#endif
       , testProperty "foldrWithKey" pFoldrWithKey
       , testProperty "foldlWithKey" pFoldlWithKey
       , testProperty "foldrWithKey'" pFoldrWithKey'

unordered-containers.cabal

@@ -30,13 +30,12 @@ extra-source-files: CHANGES.md
 
 tested-with:
   GHC ==9.2.1
-   || ==9.0.1
+   || ==9.0.2
    || ==8.10.7
    || ==8.8.4
    || ==8.6.5
    || ==8.4.4
    || ==8.2.2
-   || ==8.0.2
 
 flag debug
   description:  Enable debug support
@@ -54,8 +53,8 @@ library
     Data.HashSet.Internal
 
   build-depends:
-    base >= 4.9 && < 5,
-    deepseq >= 1.1,
+    base >= 4.10 && < 5,
+    deepseq >= 1.4.3,
     hashable >= 1.0.1.1 && < 1.5,
     template-haskell < 2.19
 
@@ -70,11 +69,6 @@ library
 
   ghc-options: -Wall -O2 -fwarn-tabs -ferror-spans
 
-  if impl (ghc < 8.2)
-    -- This is absolutely necessary (but not sufficient) for correctness due to
-    -- the referential-transparency-breaking mutability in unsafeInsertWith. See
-    -- #147 and GHC #13615 for details. The bug was fixed in GHC 8.2.
-    ghc-options: -feager-blackholing
   if flag(debug)
     cpp-options: -DASSERTS
 

utils/Stats.hs

@@ -27,9 +27,6 @@ instance Semigroup Histogram where
 
 instance Monoid Histogram where
     mempty = H 0 0 0 0 0
-#if __GLASGOW_HASKELL__ < 803
-    mappend = (<>)
-#endif
 
 -- | Count the number of node types at each level
 nodeHistogram :: HM.HashMap k v -> [Histogram]