(Glad I started this discussion; thank you Nathan for the enlightening links, I
need to review all my code now!)
Jeff, maybe what we need is a new value type that advertizes that it's
unsigned, but doesn't have the unwanted 2^N wrapping (and its effects on
bug-finding tools and compiler optimizations).
`class Unsigned { int mValue; /* magic API here */ }` -- feels like unsigned,
but underneath it's all `int` arithmetics, with optional >=0 assertions.
Would that help?
Gerald
On Friday, July 5, 2019 at 5:35:30 AM UTC+10, Jeff Gilbert wrote:
> That's what CheckedInt is for, and that's what we use.
>
> The problems webgl deals with aren't arithmatic. Arithmatic is easy.
> (CheckedInt!) Reasoning about constraints is hard.
>
> We have some entrypoints where negative values are valid, and many
> where they are not. It's really nice to have a natural way to document
> which we expect /at compile time/. Saying "no unsigned types" really
> throws out the baby with the bathwater for me.
>
> On Thu, Jul 4, 2019 at 11:46 AM Botond Ballo <bba...@mozilla.com> wrote:
> >
> > On Thu, Jul 4, 2019 at 2:03 PM Jeff Gilbert <jgi...@mozilla.com> wrote:
> > > It's a huge
> > > help to have a compile-time constraint that values can't be negative.
> >
> > The question is, how useful is that guarantee. Suppose you have some
> > code that decrements an integer too far, past zero. Instead of having
> > a -1 you'll have a 4294967295. Is that an improvement? Will it give
> > the code saner behaviour than the -1?
> >
> > Cheers,
> > Botond
_______________________________________________
dev-platform mailing list
dev-platform@lists.mozilla.org
https://lists.mozilla.org/listinfo/dev-platform
