Couldn't match expected type `a' with actual type `[a]'

Question

I was able to execute the following code flawlessly

myLast :: [a] -> a
myLast [] = error \"Can\'t call myLast on an empty list!\"
myLast (x:_) = x
         


        

Answer 1

(_:x) matches _ with the head and x with the tail of the list. The type of tail of a list is [a]. You are trying to return [a]' where as the function declaration specifies return type as a.

myLast (_:x) = x

If you want to match last element take a look at this answer - Can you use pattern matching to bind the last element of a list?