basic mhs compatibility

Author: L0neGamer

.gitignore

@@ -1,3 +1,4 @@
 dist-newstyle
+dist-mcabal
 .ghc.environment.*
 cabal.project.local

OneTuple.cabal

@@ -45,22 +45,26 @@ library
   exposed-modules:
     Data.Tuple.OneTuple
     Data.Tuple.Solo
-    Data.Tuple.Solo.TH
+
+  if impl(ghc)
+    exposed-modules:
+      Data.Tuple.Solo.TH
+    build-depends:
+      template-haskell
 
   hs-source-dirs:   src
   build-depends:
       base              >=4.12 && <4.23
-    , template-haskell
 
   if impl(ghc >=9.0)
     build-depends: ghc-prim
   else
     build-depends: hashable >=1.3.5.0 && <1.6
 
-  if !impl(ghc >=9.0)
+  if impl(ghc) && !impl(ghc >=9.0)
     build-depends: foldable1-classes-compat >=0.1 && <0.2
 
-  if !impl(ghc >=9.2)
+  if impl(ghc) && !impl(ghc >=9.2)
     build-depends: base-orphans >=0.8.6
 
 test-suite instances
@@ -73,13 +77,13 @@ test-suite instances
     , hashable
     , OneTuple
 
-  if !impl(ghc >=8.0)
+  if impl(ghc) && !impl(ghc >=8.0)
     build-depends:
         semigroups
       , transformers
       , transformers-compat
 
-  if !impl(ghc >=9.6)
+  if impl(ghc) && !impl(ghc >=9.6)
     build-depends: foldable1-classes-compat >=0.1 && <0.2
 
 test-suite th

src/Data/Tuple/Solo.hs

@@ -30,7 +30,22 @@ module Data.Tuple.Solo (
 import Data.Orphans ()
 #endif
 
-#if MIN_VERSION_base(4,18,0)
+#if defined(__MHS__)
+import Data.Tuple (Solo (MkSolo), getSolo)
+
+pattern Solo :: a -> Solo a
+pattern Solo a = Solo a
+
+{-# COMPLETE Solo #-}
+
+instance (Enum a) => Enum (Solo a) where
+    succ = fmap succ
+    pred = fmap pred
+    toEnum = pure . toEnum
+    fromEnum (MkSolo x) = fromEnum x
+
+
+#elif MIN_VERSION_base(4,18,0)
 import GHC.Tuple (Solo (MkSolo, Solo), getSolo)