refactor: Remove unnecessary promotion ticks

Unticked promoted constructors are the encouraged default as of GHC 9.4
(see [1]). We remove unnecessary ticks from type families, and disable
-Wunticked-promoted-constructors on GHC 9.2.

[1]: https://gitlab.haskell.org/ghc/ghc/-/issues/20531

Author: pgujjula

package.yaml

@@ -44,6 +44,10 @@ ghc-options:
 - -Wpartial-fields
 - -Wredundant-constraints
 - -Wunused-packages
+when:
+- condition: impl(ghc < 9.4)
+  ghc-options:
+  - -Wno-unticked-promoted-constructors
 
 library:
   source-dirs: src

src/VCard/Symbol/Private/Case.hs

@@ -45,8 +45,8 @@ sToLower :: SSymbol s -> SSymbol (ToLower s)
 sToLower ss = sToLowerUncons (sUnconsSymbol ss)
 
 type family ToLowerUncons (mcs :: Maybe (Char, Symbol)) :: Symbol where
-  ToLowerUncons 'Nothing = ""
-  ToLowerUncons ('Just '(c, s)) = ConsSymbol (ToLowerChar c) (ToLower s)
+  ToLowerUncons Nothing = ""
+  ToLowerUncons (Just '(c, s)) = ConsSymbol (ToLowerChar c) (ToLower s)
 
 sToLowerUncons :: SMaybe mcs -> SSymbol (ToLowerUncons mcs)
 sToLowerUncons = \case
@@ -131,8 +131,8 @@ sToUpper :: SSymbol s -> SSymbol (ToUpper s)
 sToUpper ss = sToUpperUncons (sUnconsSymbol ss)
 
 type family ToUpperUncons (mcs :: Maybe (Char, Symbol)) :: Symbol where
-  ToUpperUncons 'Nothing = ""
-  ToUpperUncons ('Just '(c, s)) = ConsSymbol (ToUpperChar c) (ToUpper s)
+  ToUpperUncons Nothing = ""
+  ToUpperUncons (Just '(c, s)) = ConsSymbol (ToUpperChar c) (ToUpper s)
 
 sToUpperUncons :: SMaybe mcs -> SSymbol (ToUpperUncons mcs)
 sToUpperUncons = \case

src/VCard/Symbol/Private/Prefix.hs

@@ -25,14 +25,14 @@ type family IsPrefixOfInsensitive (s :: Symbol) (t :: Symbol) :: Bool where
   IsPrefixOfInsensitive s t = IsPrefixOf (ToLower s) (ToLower t)
 
 type family IsPrefixOfList (s :: [Char]) (t :: [Char]) :: Bool where
-  IsPrefixOfList '[] '[] = 'True
-  IsPrefixOfList '[] (y ': ys) = 'True
-  IsPrefixOfList (x ': xs) (y ': ys) = (x == y) && IsPrefixOfList xs ys
-  IsPrefixOfList (x ': xs) '[] = 'False
+  IsPrefixOfList '[] '[] = True
+  IsPrefixOfList '[] (y : ys) = True
+  IsPrefixOfList (x : xs) (y : ys) = (x == y) && IsPrefixOfList xs ys
+  IsPrefixOfList (x : xs) '[] = False
 
 type family ToList (s :: Symbol) :: [Char] where
   ToList s = ToListUncons (UnconsSymbol s)
 
 type family ToListUncons (x :: (Maybe (Char, Symbol))) :: [Char] where
-  ToListUncons 'Nothing = '[]
-  ToListUncons ('Just '(c, s)) = c ': ToList s
+  ToListUncons Nothing = '[]
+  ToListUncons (Just '(c, s)) = c : ToList s

vcard.cabal

@@ -75,6 +75,8 @@ library
     , text >=1.2 && <1.3 || >=2.0 && <2.1 || >=2.1 && <2.2
     , vary ==0.1.*
   default-language: Haskell2010
+  if impl(ghc < 9.4)
+    ghc-options: -Wno-unticked-promoted-constructors
   if impl(ghc >= 9.6)
     other-modules:
         VCard.Symbol.Private.Compat.New
@@ -157,6 +159,8 @@ test-suite vcard-tests
     , time >=1.11 && <1.12 || >=1.12 && <1.13 || >=1.14 && <1.15
     , vary ==0.1.*
   default-language: Haskell2010
+  if impl(ghc < 9.4)
+    ghc-options: -Wno-unticked-promoted-constructors
   if impl(ghc >= 9.6)
     other-modules:
         VCard.Symbol.Private.Compat.New