From https://github.com/quchen/pgp-wordlist/commit/214304abc2b9b1213e6ea0f4bcc6f0b8033ada22
From: Topsii <tobiashaslop@hotmail.de>
Date: Mon, 17 Oct 2022 23:51:27 +0200
Subject: [PATCH] Add missing Functor instance for AltList

Adresses haskell/core-libraries-committee#91
--- a/src/Data/Text/PgpWordlist/Internal/AltList.hs
+++ b/src/Data/Text/PgpWordlist/Internal/AltList.hs
@@ -81,7 +81,8 @@ bimap :: (a -> a') -> (b -> b') -> AltList a b -> AltList a' b'
 bimap _ _ Nil = Nil
 bimap f g (x :<> xs) = f x :<> bimap g f xs
 
-
+instance Functor (AltList a) where
+    fmap = second
 
 #if MIN_VERSION_base(4,8,0)
 instance Bi.Bifunctor AltList where