Ask user for list input in Haskell

Question

I found this code online, but it's not running.

main = do
 xs <- getLine []
print xs

So how do I ask the user for list input in Haskell? I am new to Haskell, please explain when you answer. Thanks.

Answer 1

You do it e.g. like this:

main :: IO ()
main = do
  xs <- getLine
  let { ints :: [Int] 
      ; ints = read xs 
      }
  print $ take 2 ints
  

and you must type in the input in a valid list syntax, e.g.

[1,2,3]

Do take note, each line in a do-block must start at the same indentation level (unless explicit separators { ; } are used).