[Haskell-cafe] Using unsafePerformIO
Dinh Tien Tuan Anh
tuananhbirm at hotmail.com
Mon Aug 1 07:24:49 EDT 2005
>So that's not safe, and thus it should be in the IO monad.
How can i handle a lazy list with IO monad.
For example, function
¦c ==1 = 1:co (xs)
¦c == 2 = 0:co (xs)
where c = unsafePerformIO(f (x:xs))
will be written without unsafePerformIO:
co' (x:xs) = do
c1 <- co' xs
c<- f (x:xs)
then return 1:c1
else return 0:c1
AFAICS, co' does not do lazy evaluation, so wont print any element of the
Can lazy evaluation be integrated with IO monad ?
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