Unique

ID作る系。

% runhaskell
import Data.Unique

main :: IO ()
main = do
  loop 10 $ do u <- newUnique
               print $ hashUnique u
  where loop :: Int -> IO () -> IO ()
        loop n action = if n == 0
                        then return ()
                        else action >> loop (n - 1) action

【実行結果】
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