[Haskell-beginners] Running a list of functions

Ertugrul Soeylemez es at ertes.de
Sat Aug 20 21:35:02 CEST 2011


Ozgur Akgun <ozgurakgun at gmail.com> wrote:

> Actually in this case sequence and sequence_ are identical. You have
> IO for m, and () for a, so:
>
> sequence  :: [IO ()] -> IO ()
> sequence_ :: [IO ()] -> IO ()

No, compare the type signatures:

    sequence  :: [IO ()] -> IO [()]
    sequence_ :: [IO ()] -> IO ()

In the former case you will receive a list of as many values of type ()
as there are actions.


Greets,
Ertugrul


-- 
nightmare = unsafePerformIO (getWrongWife >>= sex)
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