feat: Read and Show for all the types

src/Language/Scalie/Ast/Module.hs

@@ -1,13 +1,27 @@
 {-# LANGUAGE Safe #-}
-{-# LANGUAGE StandaloneKindSignatures #-}
+{-# LANGUAGE StandaloneKindSignatures #-} -- because of -Weverything
+{-# LANGUAGE StandaloneDeriving #-} -- to specify contexts
+{-# LANGUAGE FlexibleContexts #-} -- 'non type-variable argument'
+{-# LANGUAGE UndecidableInstances #-} -- instance head no smaller...
 module Language.Scalie.Ast.Module (Module(..)) where
 
 import Data.Kind (Type)
 import Language.Scalie.Ast.Definition (Definition)
 import Data.Map.Implicit (ImplicitMap)
+import Text.Show ( Show )
+import Text.Read (Read)
+import Data.Text (Text)
+import Language.Scalie.Ast.Expression (Expression)
+import Language.Scalie.Domain.Type qualified as Scalie.Domain
+import Data.Ord (Ord)
+
+-- | A module groups multiple related definitions.
 
 type Module :: (Type -> Type) -> Type
 type role Module nominal
 data Module f = Module
   { definitions :: ImplicitMap (Definition f)
   }
+
+deriving stock instance (Show (f Text), Show (f Expression), Show (f Scalie.Domain.Type)) => Show (Module f)
+deriving stock instance (Read (f Text), Ord (f Text), Read (f Expression), Read (f Scalie.Domain.Type)) => Read (Module f)