[following-up to my own post] On Sun, Aug 21, 2011 at 11:44 AM, Zooko O'Whielacronx <zo...@zooko.com> wrote: > > The behavior of a program is a deterministic function of its source > code, right? So if the source code (*all* of it -- everything that > gets imported and executed at any point during the run of the program) > is identical, then the behavior will be identical, and then re-using > compiled code from previous runs would always yield a correct result. > Am I still on track so far?
Uh-oh, I think I may have already gone off track here in the first paragraph. What if you use information from the runtime *inputs* -- not imported code but inputted data -- to change how you compile the code? Then even if *all* of the source code is exactly the same, re-using the compiled code from the previous run may generate incorrect results. Is that right? Solving that one is still, in my opinion, theoretically possible, but now in addition to the formidable challenge of finding safe boundaries where the knock-on effects of changed source code don't cross, we would *also* have to find boundaries of the effects of changed data inputs. This is, of course, one of those grand challenges that the programming languages researchers have been knocking their collective heads against for at least thirty years. Therefore I expect the PyPy project will have to work on it for at least a year or two more before you solve it. ;-) Regards, Zooko _______________________________________________ pypy-dev mailing list pypy-dev@python.org http://mail.python.org/mailman/listinfo/pypy-dev
