In article <[EMAIL PROTECTED]>, Michael Hudson <[EMAIL PROTECTED]> wrote:
> Donn Cave <[EMAIL PROTECTED]> writes: > > > On the contrary, there are a couple. Ghc is probably the > > leading implementation these days, and by any reasonable > > measure, it is serious. > > > > Objective CAML is indeed not a pure functional language. > > *cough* unsafePerformIO *cough* (Hope that cough isn't anything serious.) The way I understand it, you'd be a fool to use unsafePerformIO in a way that would generally compromise functional purity. It really is "unsafe", inasmuch as it violates central assumptions of the language evaluation model. Some people take "pure" too seriously. In this context, functional purity just means that we know that in principle, the value of an expression is constant - given the same inputs to a function, we always expect the same result. It doesn't mean "free from blemish." unsafePerformIO is a sort of blemish, I suppose, but it's a pure functional language in my book. Donn Cave, [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
