just to show some simple things

UnsafeValueVsUnsafeFunction.hs

module Unsafe where

import System.Random
import System.IO.Unsafe(unsafePerformIO)

generateUUID :: () -> String
generateUUID () = show $ unsafePerformIO (randomIO :: IO Int)

wuiPanel :: () ->  IO String
wuiPanel () = do
    return $ "Hey " ++ uuid
    where
        uuid = generateUUID ()

generateUUID' :: String
generateUUID' = show $ unsafePerformIO (randomIO :: IO Int)

wuiPanel' :: IO String
wuiPanel' = do
    return $ "Hey " ++ uuid
    where
        uuid = generateUUID'

----------------------------------
-- Example run in GHCi

> wuiPanel'
"Hey 8392539819302952191"
> wuiPanel'
"Hey 8392539819302952191"
> wuiPanel'
"Hey 8392539819302952191"
> wuiPanel()
"Hey 5880651860501659846"
> wuiPanel()
"Hey 3355626182084962896"
> wuiPanel()
"Hey 6303352265620553643"