関数型プログラミング言語Haskell Part33

[680 デフォルトの名無しさん 2021/01/23(土) 22:12:27.68 ID:u7XOzuV6]

>>679
できたー！
module Rand2 where

-- stack install list-t
-- stack exec ghci

import Control.Monad.IO.Class ( liftIO )
import ListT ( ListT, toList, cons, take )
import System.Random ( Random(randomIO) )

t2 :: ListT IO Int
t2 = liftIO (randomIO :: IO Int)

t3 :: ListT IO Int
t3 = do
x <- t2
cons x t3

output :: IO ()
output = do
li <- toList $ ListT.take 10 t3
print li

{-
*Rand2> output
[7616927328998369033,6970782903781268443,-1509938769401207081,-2789264750098693865,-6524417077297424569,8403979199680420436,-3097298192134792937,-2736699795503652525,-4754186463647322678,5658901448509988002]
-}