Guards vs. if-then-else vs. cases in Haskell

Question

I have three functions that find the nth element of a list:

nthElement :: [a] -> Int -> Maybe a 
nthElement [] a = Nothing
nthElement (x:xs) a | a <= 0          


        

Answer 1

This is just a matter of ordering but I think its very readable and has the same structure as guards.

nthElement :: [a] -> Int -> Maybe a 
nthElement [] a = Nothing
nthElement (x:xs) a = if a  < 1 then Nothing else
                      if a == 1 then Just x
                      else nthElement xs (a-1)

The last else doesn't need and if since there is no other possibilities, also functions should have "last resort case" in case you missed anything.