Drop support for GHC < 8.10 (#510)

* Drop support for GHC < 8.10

* Require nothunks unconditionally

* Remove dependency on mtl

* Remove conditions from ghc-options

Author: sjakobi

.github/workflows/haskell-ci.yml

@@ -8,9 +8,9 @@
 #
 # For more information, see https://github.com/haskell-CI/haskell-ci
 #
-# version: 0.19.20250506
+# version: 0.19.20250917
 #
-# REGENDATA ("0.19.20250506",["github","unordered-containers.cabal"])
+# REGENDATA ("0.19.20250917",["github","unordered-containers.cabal"])
 #
 name: Haskell-CI
 on:
@@ -20,6 +20,9 @@ on:
   pull_request:
     branches:
       - master
+  merge_group:
+    branches:
+      - master
 jobs:
   linux:
     name: Haskell-CI - Linux - ${{ matrix.compiler }}
@@ -72,41 +75,21 @@ jobs:
             compilerVersion: 8.10.7
             setup-method: ghcup
             allow-failure: false
-          - compiler: ghc-8.8.4
-            compilerKind: ghc
-            compilerVersion: 8.8.4
-            setup-method: ghcup
-            allow-failure: false
-          - compiler: ghc-8.6.5
-            compilerKind: ghc
-            compilerVersion: 8.6.5
-            setup-method: ghcup
-            allow-failure: false
-          - compiler: ghc-8.4.4
-            compilerKind: ghc
-            compilerVersion: 8.4.4
-            setup-method: ghcup
-            allow-failure: false
-          - compiler: ghc-8.2.2
-            compilerKind: ghc
-            compilerVersion: 8.2.2
-            setup-method: ghcup
-            allow-failure: false
       fail-fast: false
     steps:
       - name: apt-get install
         run: |
           apt-get update
-          apt-get install -y --no-install-recommends gnupg ca-certificates dirmngr curl git software-properties-common libtinfo5 libnuma-dev
+          apt-get install -y --no-install-recommends gnupg ca-certificates dirmngr curl git software-properties-common libtinfo5
       - name: Install GHCup
         run: |
           mkdir -p "$HOME/.ghcup/bin"
           curl -sL https://downloads.haskell.org/ghcup/0.1.50.1/x86_64-linux-ghcup-0.1.50.1 > "$HOME/.ghcup/bin/ghcup"
           chmod a+x "$HOME/.ghcup/bin/ghcup"
       - name: Install cabal-install
         run: |
-          "$HOME/.ghcup/bin/ghcup" install cabal 3.14.2.0 || (cat "$HOME"/.ghcup/logs/*.* && false)
-          echo "CABAL=$HOME/.ghcup/bin/cabal-3.14.2.0 -vnormal+nowrap" >> "$GITHUB_ENV"
+          "$HOME/.ghcup/bin/ghcup" install cabal 3.16.0.0 || (cat "$HOME"/.ghcup/logs/*.* && false)
+          echo "CABAL=$HOME/.ghcup/bin/cabal-3.16.0.0 -vnormal+nowrap" >> "$GITHUB_ENV"
       - name: Install GHC (GHCup)
         if: matrix.setup-method == 'ghcup'
         run: |
@@ -182,7 +165,7 @@ jobs:
           chmod a+x $HOME/.cabal/bin/cabal-plan
           cabal-plan --version
       - name: checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           path: source
       - name: initial cabal.project for sdist
@@ -207,7 +190,11 @@ jobs:
           touch cabal.project.local
           echo "packages: ${PKGDIR_unordered_containers}" >> cabal.project
           echo "package unordered-containers" >> cabal.project
-          echo "    ghc-options: -Werror=missing-methods" >> cabal.project
+          echo "    ghc-options: -Werror=missing-methods -Werror=missing-fields" >> cabal.project
+          if [ $((HCNUMVER >= 90400)) -ne 0 ] ; then echo "package unordered-containers" >> cabal.project ; fi
+          if [ $((HCNUMVER >= 90400)) -ne 0 ] ; then echo "    ghc-options: -Werror=unused-packages" >> cabal.project ; fi
+          if [ $((HCNUMVER >= 90000)) -ne 0 ] ; then echo "package unordered-containers" >> cabal.project ; fi
+          if [ $((HCNUMVER >= 90000)) -ne 0 ] ; then echo "    ghc-options: -Werror=incomplete-patterns -Werror=incomplete-uni-patterns" >> cabal.project ; fi
           cat >> cabal.project <<EOF
           EOF
           $HCPKG list --simple-output --names-only | perl -ne 'for (split /\s+/) { print "constraints: any.$_ installed\n" unless /^(binary|containers|unordered-containers)$/; }' >> cabal.project.local

Data/HashMap/Internal.hs

@@ -192,11 +192,7 @@ instance (NFData k, NFData v) => NFData (Leaf k v) where
 
 -- | @since 0.2.17.0
 instance (TH.Lift k, TH.Lift v) => TH.Lift (Leaf k v) where
-#if MIN_VERSION_template_haskell(2,16,0)
   liftTyped (L k v) = [|| L k $! v ||]
-#else
-  lift (L k v) = [| L k $! v |]
-#endif
 
 -- | @since 0.2.14.0
 instance NFData k => NFData1 (Leaf k) where

Data/HashMap/Internal/Array.hs

@@ -207,18 +207,13 @@ new _n@(I# n#) b =
 new_ :: Int -> ST s (MArray s a)
 new_ n = new n undefinedElem
 
--- | When 'Exts.shrinkSmallMutableArray#' is available, the returned array is the same as the array given, as it is shrunk in place.
--- Otherwise a copy is made.
+-- | The returned array is the same as the array given, as it is shrunk in place.
 shrink :: MArray s a -> Int -> ST s (MArray s a)
-#if __GLASGOW_HASKELL__ >= 810
 shrink mary _n@(I# n#) =
   CHECK_GT("shrink", _n, (0 :: Int))
   CHECK_LE("shrink", _n, (lengthM mary))
   ST $ \s -> case Exts.shrinkSmallMutableArray# (unMArray mary) n# s of
     s' -> (# s', mary #)
-#else
-shrink mary n = cloneM mary 0 n
-#endif 
 {-# INLINE shrink #-}
 
 singleton :: a -> Array a
@@ -516,11 +511,7 @@ fromList' n xs0 =
 
 -- | @since 0.2.17.0
 instance TH.Lift a => TH.Lift (Array a) where
-#if MIN_VERSION_template_haskell(2,16,0)
   liftTyped ar = [|| fromList' arlen arlist ||]
-#else
-  lift ar = [| fromList' arlen arlist |]
-#endif
     where
       arlen = length ar
       arlist = toList ar

Data/HashMap/Internal/Debug.hs

@@ -35,11 +35,6 @@ import Data.Semigroup        (Sum (..))
 
 import qualified Data.HashMap.Internal.Array as A
 
-
-#if !MIN_VERSION_base(4,11,0)
-import Data.Semigroup (Semigroup (..))
-#endif
-
 data Validity k = Invalid (Error k) SubHashPath | Valid
   deriving (Eq, Show)
 

Data/HashMap/Internal/List.hs

@@ -28,9 +28,6 @@ module Data.HashMap.Internal.List
 
 import Data.List  (sortBy)
 import Data.Maybe (fromMaybe)
-#if !MIN_VERSION_base(4,11,0)
-import Data.Semigroup ((<>))
-#endif
 
 -- Note: previous implementation isPermutation = null (as // bs)
 -- was O(n^2) too.

tests/Regressions.hs

@@ -29,12 +29,8 @@ import qualified Data.HashMap.Strict as HMS
 import qualified Data.HashSet        as HS
 import qualified Test.Tasty          as Tasty
 
-#if MIN_VERSION_base(4,12,0)
--- nothunks requires base >= 4.12
-#define HAVE_NOTHUNKS
 import qualified Data.Foldable  as Foldable
 import           NoThunks.Class (noThunksInValues)
-#endif
 
 issue32 :: Assertion
 issue32 = assert $ isJust $ HMS.lookup 7 m'
@@ -141,7 +137,6 @@ issue254Strict = do
 ------------------------------------------------------------------------
 -- Issue #379
 
-#ifdef HAVE_NOTHUNKS
 
 issue379Union :: Assertion
 issue379Union = do
@@ -167,8 +162,6 @@ issue379StrictUnionWithKey = do
   mThunkInfo <- noThunksInValues mempty (Foldable.toList u)
   assert $ isNothing mThunkInfo
 
-#endif
-
 -- Another key type that always collides.
 --
 -- Note (sjakobi): The KC newtype of Int somehow can't be used to demonstrate
@@ -196,8 +189,6 @@ issue379LazyUnionWith = do
 ------------------------------------------------------------------------
 -- Issue #381
 
-#ifdef HAVE_NOTHUNKS
-
 issue381mapMaybe :: Assertion
 issue381mapMaybe = do
   let m0 = HMS.fromList [(KC 1, 10), (KC 2, 20 :: Int)]
@@ -212,8 +203,6 @@ issue381mapMaybeWithKey = do
   mThunkInfo <- noThunksInValues mempty (Foldable.toList m1)
   assert $ isNothing mThunkInfo
 
-#endif
-
 ------------------------------------------------------------------------
 -- Issue #382
 
@@ -234,8 +223,6 @@ issue382 = do
 ------------------------------------------------------------------------
 -- Issue #383
 
-#ifdef HAVE_NOTHUNKS
-
 -- Custom Functor to prevent interference from alterF rules
 newtype MyIdentity a = MyIdentity a
 instance Functor MyIdentity where
@@ -250,8 +237,6 @@ issue383 = do
   mThunkInfo <- noThunksInValues mempty (Foldable.toList m)
   assert $ isNothing mThunkInfo
 
-#endif
-
 ------------------------------------------------------------------------
 -- Issue #420
 
@@ -288,22 +273,16 @@ tests = testGroup "Regression tests"
     , testCase "issue254 strict" issue254Strict
     , testGroup "issue379"
           [ testCase "Lazy.unionWith" issue379LazyUnionWith
-#ifdef HAVE_NOTHUNKS
           , testCase "union" issue379Union
           , testCase "Strict.unionWith" issue379StrictUnionWith
           , testCase "Strict.unionWithKey" issue379StrictUnionWithKey
-#endif
           ]
-#ifdef HAVE_NOTHUNKS
     , testGroup "issue381"
           [ testCase "mapMaybe" issue381mapMaybe
           , testCase "mapMaybeWithKey" issue381mapMaybeWithKey
           ]
-#endif
     , testCase "issue382" issue382
-#ifdef HAVE_NOTHUNKS
     , testCase "issue383" issue383
-#endif
     , testCase "issue420" issue420
     , issue491
     ]

unordered-containers.cabal

@@ -37,10 +37,6 @@ tested-with:
    || ==9.2.8
    || ==9.0.2
    || ==8.10.7
-   || ==8.8.4
-   || ==8.6.5
-   || ==8.4.4
-   || ==8.2.2
 
 flag debug
   description:  Enable debug support
@@ -59,10 +55,10 @@ library
     Data.HashSet.Internal
 
   build-depends:
-    base >= 4.10 && < 5,
+    base >= 4.14 && < 5,
     deepseq >= 1.4.3,
     hashable >= 1.4 && < 1.6,
-    template-haskell < 2.24
+    template-haskell >= 2.16 && < 2.24
 
   default-language: Haskell2010
 
@@ -104,16 +100,13 @@ test-suite unordered-containers-tests
     hashable,
     HUnit,
     QuickCheck >= 2.4.0.1,
+    nothunks >= 0.1.3,
     random,
     tasty >= 1.4.0.3,
     tasty-hunit >= 0.10.0.3,
     tasty-quickcheck >= 0.10.1.2,
     unordered-containers
 
-  if impl(ghc >= 8.6)
-    build-depends:
-      nothunks >= 0.1.3
-
   default-language: Haskell2010
   ghc-options: -Wall -threaded -rtsopts -with-rtsopts=-N
   cpp-options: -DASSERTS
@@ -135,15 +128,12 @@ benchmark benchmarks
     deepseq,
     hashable,
     hashmap,
-    mtl,
     random,
     tasty-bench >= 0.3.1,
     unordered-containers
 
   default-language: Haskell2010
-  ghc-options: -Wall -O2 -rtsopts -with-rtsopts=-A32m
-  if impl(ghc >= 8.10)
-    ghc-options: "-with-rtsopts=-A32m --nonmoving-gc"
+  ghc-options: -Wall -O2 -rtsopts "-with-rtsopts=-A32m --nonmoving-gc"
   -- cpp-options: -DBENCH_containers_Map -DBENCH_containers_IntMap -DBENCH_hashmap_Map
 
 source-repository head