On 26/09/2007, Jorge Marques Pelizzoni
Hi, all!
This is a newbie question: I sort of understand what unsafePerformIO does but I don't quite get its consequences. In short: how safe can one be in face of it? I mean, conceptually, it allows any Haskell function to have side effects just as in any imperative language, doesn't it? Doesn't it blow up referential transparency for good? Is there anything intrinsic to it that still keeps Haskell "sound" no matter what unsafePerformIO users do (unlikely) or else what are the guidelines we should follow when using it?
Rule of thumb: If your name isn't Simon*, you shouldn't use unsafePerformIO. * http://research.microsoft.com/~simonpj/ https://research.microsoft.com/~simonmar/ -- Sebastian Sylvan +44(0)7857-300802 UIN: 44640862