CODEWITHSUNDEEP
haskell
R.N
R.N

Reputation: 109

Extracting elements from the start of a list in Haskell without the builtin function

I want to write a function that extracts n number of elements from the start of a list in Haskell. I know it can be done using the built-in 'take' function and I have done it, which works. However, I can't seem to write a function without take. This is my code.

takeElem' :: Int -> [t] -> [t]
takeElem' _ [] = []
takeElem' n (x:xs) = [x] ++ takeElem' (n-1) xs

This code complies fine but when I test it for example

takeElem' 3 "hello"

It returns "hello" instead of "hel"

Any idea what could be wrong?

Upvotes: 0

Views: 97

Answers (2)

PedroCastro
PedroCastro

Reputation: 71

It should be 0 _ instead of _ []. Because you are saying it is [] when you took everything of the list instead of [] when your n reaches 0.

Upvotes: 0

R.N
R.N

Reputation: 109

I didn't add what should happen in the case when n is zero. I just added

takeElem' 0 list = []

it works now.

Upvotes: 2

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