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.

Kotlin translation waiting for approval

I'm (still) experiencing floating point errors.

can compute general complex signum
expected: Complex 0.6 0.8
 but got: Complex 0.6000000000000001 0.8

Edit: I "solved" the problem by explicitly defining division (/) instead of only defining recip. Now my solution passes all example test cases. However when I submit it, it still gives an error every time.

can compute general complex signum
Falsifiable (after 1 test and 309 shrinks): 
NonZero {getNonZero = 1.4e-44}
NonZero {getNonZero = 1.0e-45}

If you structure main as

main = do
  hspec $ do
    describe "" $ do
      it "" $ do
        x `shouldBe` y
  hspec $ do
    describe "" $ do
      it "" $ do
        a `shouldBe` b

you don't increase the test indent continuously.

Quite unessential, but I think it looks better.