[Haskell] Re: Global Variables and IO initializers

Tomasz Zielonka tomasz.zielonka at gmail.com
Wed Nov 24 03:35:55 EST 2004

On Wed, Nov 24, 2004 at 08:53:47AM +0100, Lennart Augustsson wrote:
> Well, I don't.  unsafePerformIO is an extension that is very much
> against the spirit of Haskell.  Haskell with it does not have the
> properties I want.  So I don't use it. :)

I hope 'it' means unsafePerformIO, not Haskell :)

I agree. Without unsafePerformIO Haskell gives me many guarantees for free.
With unsafePerformIO, they are no longer for free, I have to think, prove,
etc. When I mistakenly give a pure function interface to an unpure
"function", it can affect my program in most unexpected places.

Best regards,

More information about the Haskell mailing list