i do not use any type applications, but for convienience i implement some prelude function such as catMaybeS and so on. is that affect?

Have you use type application?
After removing type applications, I pass all the tests.

Failed to parse solution for "do not use implemented Prelude" test, got messsage:

uncaught exception: IOException of type UserError
user error (Could not parse solution correctly)

But I really cannot findout which function in my code is the 'implemented Prelude', can we provide more specific limits?

besides, here is the Prelude functions I used:

(,), Just, Nothing, (:), ([]), Left, Right  

The tests should limit the imports from the solution to only those being tested, as any defined helpers may clash with names in the tests.

That kata has been sent back to draft, closing

Approved

python new test framework is required. updated in this fork

nice kata!

Great kata!

Very nice kata. There are enough "foundational" katas nowadays that can give practice, that it made it feel quite doable. Still very enjoyable :)

Indeed! Thanks :)

Fixed

Kotlin translation waiting for approval