[D-runtime] Is core.math public API?

[Alex Rønne Petersen]

On Tue, Oct 2, 2012 at 8:44 PM, David Nadlinger <code at klickverbot.at> wrote:
> On Tue, Oct 2, 2012 at 6:45 PM, Alex Rønne Petersen <xtzgzorex at gmail.com> wrote:
>> It isn't.
>>
>> See: http://article.gmane.org/gmane.comp.lang.d.runtime/1187/match=core+math
>
> In my opinion, saying that something isn't part of the public druntime
> API, but at the same time is intended to be used from Phobos doesn't
> make much sense. After all, the whole point behind druntime (well, one
> of them) was to introduce a low-level abstraction layer so that Phobos
> could just be a library like any other. If Phobos ends up calling
> undocumented, private functions, "like any other" is definitely not
> true. Why would Phobos be allowed to call core.math functions, but not
> Tango or any other library?
>
> Anyway, currently std.math does not use core.math, but declares a few
> magic functions which are name-matched by DMD (the only remaining ones
> in std.*, by the way). This forces us to edit that file in the LDC
> copy of Phobos, because our intrinsics system works differently.
>
> So, would anyone object if I modify std.math to forward the functions
> to core.math instead, and add the latter to the public docs? Judging
> from Don's message linked by Alex, this was the original intention
> behind core.math anyway, and would remove one compiler dependency from
> Phobos, which is imho a desirable goal. Of course, I'd also extend the
> core.math docs with a short note mentioning that it only provides
> low-level intrinsics and std.math is to be preferred for actual
> application use.

I think this is perfectly reasonable - we need to eliminate any and
all magic support the compiler has for things in Phobos. It must be
another library or we have serious language design issues.

Regards,
Alex