Re: [Haskell-cafe] global variables

David House wrote:

On 24/05/07, Adrian Hey wrote:

...

Or even at compile time (which is why I think it's reasonable to regard operations like newIORef etc.. as not really being "IO" operations at all).

You can allocate heap space at compile time? (Well, I guess you could, but that wouldn't still be usable at run time...) I imagine newIORef as mallocing() some room, then returning a pointer to that memory. That doesn't seem like something that could be done at compile time.

There seems to be quite a few implicit (and incorrect) assumptions in your argument, which is fallacious IMO. The logic of your argument would imply that *no* top level expression can be evaluated at compile time. This might be the case with ghc, though I doubt it (and even if it was this would just be a ghc problem). BTW, the Haskell standard says nothing about any kind of heap, let alone a C style malloc. Regards -- Adrian Hey