refactor(saltine): fix hlint and ghc warnings

src/Crypto/Saltine/Instances.hs

@@ -1,5 +1,4 @@
-{-# LANGUAGE BangPatterns #-}
-{-# OPTIONS_GHC -Wwarn #-}
+{-# OPTIONS_GHC -Wwarn -fno-warn-orphans #-}
 
 -- SPDX-FileCopyrightText: 2024 Sarah Vaupel <sarah.vaupel@uniworx.de>
 --
@@ -50,7 +49,7 @@ buildUnsafeByteString' n k = do
 -- | Convenience function for accessing constant C strings
 constByteStrings :: [ByteString] -> ([CStringLen] -> IO b) -> IO b
 constByteStrings =
-  foldr (\v kk -> \k -> (unsafeUseAsCStringLen v) (\a -> kk (\as -> k (a:as)))) ($ [])
+  foldr (\v kk k -> unsafeUseAsCStringLen v (\a -> kk (\as -> k (a:as)))) ($ [])
 
 -- | bin2hex conversion for showing various binary types
 foreign import ccall unsafe "sodium_bin2hex"
@@ -64,8 +63,9 @@ foreign import ccall unsafe "sodium_bin2hex"
 bin2hex :: ByteString -> String
 bin2hex bs = let tlen = S.length bs * 2 + 1 in
     S8.unpack . S8.init . snd . buildUnsafeByteString tlen $ \t ->
-        constByteStrings [bs] $ \[(pbs, _)] ->
-                c_sodium_bin2hex t (fromIntegral tlen) pbs (fromIntegral $ S.length bs)
+      let aux [(pbs, _)] = c_sodium_bin2hex t (fromIntegral tlen) pbs (fromIntegral $ S.length bs)
+          aux _          = error "Crypto.Saltine.Instances.bin2hex reached an impossible computation path"
+      in constByteStrings [bs] aux
 
 instance Show Key where
     show k = "SecretBox.Key {hashesTo = \"" <> (bin2hex . shorthash nullShKey $ encode k) <> "}\""