On Tuesday 12 Oct 2004 10:47 pm, Marcin 'Qrczak' Kowalczyk wrote: > Adrian Hey <[EMAIL PROTECTED]> writes: > > The only real insanity with the current situation is the loss of > > referential transparency implied by the use of unsafePerformIO, > > which is why various pragma hacks and compiler switches need to be > > used (in order to prevent inappropriate substitutions). What I want > > to do is to make this or something similar "official", so the > > compiler really knows not to do this inappropriate subsitution in > > any event, even if the programmer forgot to use the necessary > > pragmas or compiler flags, or just didn't understand why they are > > needed. > > It's not the only problem: > v = unsafePerformIO (newIORef undefined) :: IORef a > You can store an Integer there and try to take out a String.
Yes of course, this is a well known problem with unsafePerformIO. This is why in my earlier post I suggested that the use of special syntax would also be a cue for the compiler to impose typing restrictions. Regards -- Adrian Hey _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
