v0.2.2.1: drop support for GHC 7

.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: 0.19.20251211
 #
-# REGENDATA ("0.19.20250506",["github","newtype.cabal"])
+# REGENDATA ("0.19.20251211",["github","newtype.cabal"])
 #
 name: Haskell-CI
 on:
@@ -20,6 +20,9 @@ on:
   pull_request:
     branches:
       - master
+  merge_group:
+    branches:
+      - master
 jobs:
   linux:
     name: Haskell-CI - Linux - ${{ matrix.compiler }}
@@ -32,14 +35,19 @@ jobs:
     strategy:
       matrix:
         include:
+          - compiler: ghc-9.14.0.20251128
+            compilerKind: ghc
+            compilerVersion: 9.14.0.20251128
+            setup-method: ghcup-prerelease
+            allow-failure: false
           - compiler: ghc-9.12.2
             compilerKind: ghc
             compilerVersion: 9.12.2
             setup-method: ghcup
             allow-failure: false
-          - compiler: ghc-9.10.2
+          - compiler: ghc-9.10.3
             compilerKind: ghc
-            compilerVersion: 9.10.2
+            compilerVersion: 9.10.3
             setup-method: ghcup
             allow-failure: false
           - compiler: ghc-9.8.4
@@ -110,8 +118,8 @@ jobs:
           chmod a+x "$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: |
@@ -126,6 +134,21 @@ jobs:
           HCKIND: ${{ matrix.compilerKind }}
           HCNAME: ${{ matrix.compiler }}
           HCVER: ${{ matrix.compilerVersion }}
+      - name: Install GHC (GHCup prerelease)
+        if: matrix.setup-method == 'ghcup-prerelease'
+        run: |
+          "$HOME/.ghcup/bin/ghcup" config add-release-channel prereleases
+          "$HOME/.ghcup/bin/ghcup" install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
+          HC=$("$HOME/.ghcup/bin/ghcup" whereis ghc "$HCVER")
+          HCPKG=$(echo "$HC" | sed 's#ghc$#ghc-pkg#')
+          HADDOCK=$(echo "$HC" | sed 's#ghc$#haddock#')
+          echo "HC=$HC" >> "$GITHUB_ENV"
+          echo "HCPKG=$HCPKG" >> "$GITHUB_ENV"
+          echo "HADDOCK=$HADDOCK" >> "$GITHUB_ENV"
+        env:
+          HCKIND: ${{ matrix.compilerKind }}
+          HCNAME: ${{ matrix.compiler }}
+          HCVER: ${{ matrix.compilerVersion }}
       - name: Set PATH and environment variables
         run: |
           echo "$HOME/.cabal/bin" >> $GITHUB_PATH
@@ -136,7 +159,7 @@ jobs:
           echo "HCNUMVER=$HCNUMVER" >> "$GITHUB_ENV"
           echo "ARG_TESTS=--enable-tests" >> "$GITHUB_ENV"
           echo "ARG_BENCH=--enable-benchmarks" >> "$GITHUB_ENV"
-          echo "HEADHACKAGE=false" >> "$GITHUB_ENV"
+          if [ $((HCNUMVER >= 91400)) -ne 0 ] ; then echo "HEADHACKAGE=true" >> "$GITHUB_ENV" ; else echo "HEADHACKAGE=false" >> "$GITHUB_ENV" ; fi
           echo "ARG_COMPILER=--$HCKIND --with-compiler=$HC" >> "$GITHUB_ENV"
         env:
           HCKIND: ${{ matrix.compilerKind }}
@@ -164,6 +187,18 @@ jobs:
           repository hackage.haskell.org
             url: http://hackage.haskell.org/
           EOF
+          if $HEADHACKAGE; then
+          cat >> $CABAL_CONFIG <<EOF
+          repository head.hackage.ghc.haskell.org
+             url: https://ghc.gitlab.haskell.org/head.hackage/
+             secure: True
+             root-keys: 7541f32a4ccca4f97aea3b22f5e593ba2c0267546016b992dfadcd2fe944e55d
+                        26021a13b401500c8eb2761ca95c61f2d625bfef951b939a8124ed12ecf07329
+                        f76d08be13e9a61a377a85e2fb63f4c5435d40f8feb3e12eb05905edb8cdea89
+             key-threshold: 3
+          active-repositories: hackage.haskell.org, head.hackage.ghc.haskell.org:override
+          EOF
+          fi
           cat >> $CABAL_CONFIG <<EOF
           program-default-options
             ghc-options: $GHCJOBS +RTS -M3G -RTS
@@ -187,7 +222,7 @@ 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
@@ -212,9 +247,16 @@ jobs:
           touch cabal.project.local
           echo "packages: ${PKGDIR_newtype}" >> cabal.project
           if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then echo "package newtype" >> cabal.project ; fi
-          if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then echo "    ghc-options: -Werror=missing-methods" >> cabal.project ; fi
+          if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then echo "    ghc-options: -Werror=missing-methods -Werror=missing-fields" >> cabal.project ; fi
+          if [ $((HCNUMVER >= 90400)) -ne 0 ] ; then echo "package newtype" >> 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 newtype" >> 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
+          if $HEADHACKAGE; then
+          echo "allow-newer: $($HCPKG list --simple-output | sed -E 's/([a-zA-Z-]+)-[0-9.]+/*:\1,/g')" >> cabal.project
+          fi
           $HCPKG list --simple-output --names-only | perl -ne 'for (split /\s+/) { print "constraints: any.$_ installed\n" unless /^(newtype)$/; }' >> cabal.project.local
           cat cabal.project
           cat cabal.project.local

CHANGES.md

@@ -1,4 +1,7 @@
-See also https://pvp.haskell.org/faq
+## 0.2.2.1
+
+ - Drop support for GHC 7.
+ - Tested with GHC 8.0 - 9.14.
 
 ## 0.2.2.0
 

Control/Newtype.hs

@@ -1,13 +1,11 @@
 {-# LANGUAGE CPP                    #-}
+{-# LANGUAGE DefaultSignatures      #-}
 {-# LANGUAGE FlexibleInstances      #-}
 {-# LANGUAGE FunctionalDependencies #-}
 {-# LANGUAGE MultiParamTypeClasses  #-}
 {-# LANGUAGE TypeFamilies           #-}
-#if __GLASGOW_HASKELL__ >= 704
-{-# LANGUAGE DefaultSignatures      #-}
-#endif
 
-{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+{-# OPTIONS_GHC -Wno-unused-imports #-}
 
 {- |
 Module : Control.Newtype
@@ -42,19 +40,14 @@ module Control.Newtype
 
 import           Control.Applicative
 import           Control.Arrow
+
+import           Data.Coerce
 import           Data.Fixed
 import           Data.Functor.Compose
 import           Data.Functor.Identity
 import           Data.Monoid
 import           Data.Ord
 
-#if !MIN_VERSION_base(4,7,0)
--- necessary evil for 'Newtype Fixed'
-import           Unsafe.Coerce         (unsafeCoerce)
-#else
-import           Data.Coerce
-#endif
-
 -- | Given a @newtype@ @n@, we will always have the same unwrapped type @o@, meaning we can represent this with a fundep @n -> o@.
 --
 -- Any instance of this class just needs to let 'pack' equal to the newtype's constructor, and let 'unpack' destruct the @newtype@ with pattern matching.
@@ -72,23 +65,11 @@ class Newtype n o | n -> o where
 
   unpack :: n -> o
 
-#if  __GLASGOW_HASKELL__ >= 704
   default pack :: Coercible o n => o -> n
   pack = coerce
 
   default unpack :: Coercible n o => n -> o
   unpack = coerce
-#endif
-
-#if __GLASGOW_HASKELL__ >= 704 && !MIN_VERSION_base(4,7,0)
--- Hack: We define a dummy 'Coercible' class to force a
--- missing-instance compile error when methods are not explicitly
--- defined
-class Coercible o n
-
-coerce :: a -> b
-coerce = undefined
-#endif
 
 {- TODO: for newtype-0.3
 
@@ -196,37 +177,27 @@ instance ArrowApply a => Newtype (ArrowMonad a b) (a () b) where
 
 -- | @since 0.2.1.0
 instance Newtype (Fixed a) Integer where
-#if MIN_VERSION_base(4,7,0)
   pack = MkFixed
   unpack (MkFixed x) = x
-#else
-  -- 'Fixed' is a newtype, but its constructor wasn't exported before base-4.7.0
-  pack = unsafeCoerce
-  unpack = unsafeCoerce
-#endif
 
 -- | @since 0.2.1.0
 instance Newtype (Dual a) a where
   pack = Dual
   unpack (Dual a) = a
 
-#if MIN_VERSION_base(4,8,0)
 -- | __NOTE__: Type & instance only available with @base ≥ 4.8.0@
 --
 -- @since 0.2.1.0
 instance Newtype (Alt f a) (f a) where
   pack = Alt
   unpack (Alt x) = x
-#endif
 
-#if MIN_VERSION_base(4,6,0)
 -- | __NOTE__: Type & instance only available with @base ≥ 4.6.0@
 --
 -- @since 0.2.1.0
 instance Newtype (Down a) a where
   pack = Down
   unpack (Down a) = a
-#endif
 
 -- | @since 0.2.1.0
 instance Newtype (Identity a) a where

newtype.cabal

@@ -1,8 +1,7 @@
 cabal-version:       1.12
 build-type:          Simple
 name:                newtype
-version:             0.2.2.0
-x-revision:          3
+version:             0.2.2.1
 
 license:             BSD3
 license-file:        LICENSE
@@ -15,8 +14,9 @@ synopsis:            A typeclass and set of functions for working with newtypes.
 description:         Per Conor McBride, the 'Newtype' typeclass represents the packing and unpacking of a @newtype@, and allows you to operate under that @newtype@ with functions such as 'ala'. See "Control.Newtype" for documentation and examples.
 
 tested-with:
+   GHC == 9.14.1
    GHC == 9.12.2
-   GHC == 9.10.2
+   GHC == 9.10.3
    GHC == 9.8.4
    GHC == 9.6.7
    GHC == 9.4.8
@@ -38,20 +38,17 @@ source-repository head
 library
   exposed-modules:     Control.Newtype
 
-  build-depends:       base >= 4.3 && < 5
-  if !impl(ghc >= 8.0)
-    build-depends:     transformers >= 0.2.2.0 && < 0.6
+  build-depends:       base >= 4.9 && < 5
 
   default-language:    Haskell2010
   other-extensions:
     CPP
     FlexibleInstances
     FunctionalDependencies
     MultiParamTypeClasses
+    Trustworthy
     TypeFamilies
 
-  if impl(ghc >= 7.2)
-    default-extensions: Trustworthy
-    if impl(ghc >= 7.10) { ghc-options: -fno-warn-trustworthy-safe }
-
-  ghc-options: -Wall
+  ghc-options:
+    -Wall
+    -Wno-trustworthy-safe