вопрос по haskell

import Control.Monad
import System.IO

getValues = do 
	hFlush stdout
	input <- getLine
	let tmp = read input
	if tmp == 0
	then return []
	else liftM (tmp :) (getValues)

main = print =<< getValues

*Main> getValues 
1
2
3
0
[1,2,3]

import Control.Monad
import System.IO
import Control.Applicative

getValues = do 
	hFlush stdout
	input <- getLine
	case read input of
		0 -> return []
		x -> (x:) <$> getValues

main = print =<< getValues

Prelude> :l sample
[1 of 1] Compiling Main             ( sample.hs, interpreted )
Ok, modules loaded: Main.
*Main> getValues
1
2
3
4
5
0
[1,2,3,4,5]

input <- getLine
let tmp = read input

import Control.Monad

untilM' :: (Monad m, MonadPlus f) => (a -> Bool) -> m a -> m (f a)
untilM' p m = go where
  go = do { x <- m; if not (p x) then return mzero else mplus (return x) `liftM` go }

untilM :: Monad m => (a -> Bool) -> m a -> m [a]
untilM = untilM'

default (Int)

main :: IO ()
main = print =<< untilM (/= 0) readLn

import Control.Monad.Loops
unfoldWhileM (/= 0)  readLn