Re: [PATCH] Add arithmetic builtin functions

Jouke,

Wed, 20 May 2020 13:42:11 -0400, Paul Smith wrote:
> > Another option would be to introduce some new syntax like $(()),
> > but that might break existing Makefiles and would probably be more
> > work, though it looks cleaner IMO.

> No, I don't agree with that.  Trying to change the base make parser
> like that would be a major source of issues.

> There is already a simple way to hook in a new make function, and any
> new capabilities need to fit within the current function invocation
> model rather than creating brand-new top-level syntax.

I took that to mean that Paul prefers just adding single math functions.

Mon, 9 Dec 2024 10:37:14 +0100, Jouke Witteveen wrote:
> What I remember from the original thread is that we first needed a
> good proposal. I'm afraid the existence of the implementation
> suggested now sidesteps the discussion on what functionality is
> actually desirable.

Yeah I'm totally open to discussing a proposal further. I just felt
like having some working prototype implemented would be useful.





On Mon, Dec 9, 2024 at 1:37 AM Jouke Witteveen <[email protected]> wrote:
>
> On Mon, Dec 9, 2024 at 12:11 AM Paul Smith <[email protected]> wrote:
> > I reviewed the previous (lengthy) email thread before looking at this
> > patch.
>
> I guess you mean the thread that at some point was titled "math
> expressions" [1].
> Was there any conclusion there? At some point it gravitated to a
> shell/Posix-style expr [2] function. There were issues with most, if
> not all, proposals and personally I still think arithmetic operators
> may be too much feature creep altogether. So far, much of GNU Make's
> functionality could be summarized as a fancy rewriting language that
> produces commands to be run. The compare function introduced around
> the same time as the previous thread is already challenging this
> viewpoint, but it could still be considered an enhanced conditional
> operator. These newly proposed functions really add "numbers" as a
> supported interpretation of variable values (Bash has the same).
> Doesn't GNU Make already have Guile integration for cases where you
> want not just a rewriting engine? I know that Make is already Turing
> complete, so this argument doesn't hold in the theoretical sense, but
> still I can imagine more non-idiomatic uses of arithmetic operators
> than idiomatic ones.
>
> > I don't see the advantage in creating this special case.  If someone
> > wants the negation of a value, wouldn't they just write "-$V" instead
> > of "$(sub $V)"?
>
> This feels similar to many concerns raised in the original thread four
> years ago. In this particular case, "-$V" could result in two
> consecutive minus signs, which is probably not what we want.
>
> What I remember from the original thread is that we first needed a
> good proposal. I'm afraid the existence of the implementation
> suggested now sidesteps the discussion on what functionality is
> actually desirable.
>
> Regards,
> - Jouke
>
> [1] https://lists.gnu.org/archive/html/bug-make/2020-05/msg00070.html
> [2] https://pubs.opengroup.org/onlinepubs/9799919799/utilities/expr.html