It sucks when you have to use it for everything, but it's a useful enough technique that most Haskell datatypes come with functions that provide exactly this conversion to church encoding.

See eg 'maybe' (https://www.stackage.org/haddock/lts-18.18/base-4.14.3.0/Pre... on stackage) or foldr for lists.

'foldr' is interesting, because it encapsulates a recursive pattern matching on lists. For the non-recursive version, see 'uncons' composed with 'maybe'.