Re: Proposal

[Zack Weinberg <zack at codesourcery dot com>]

On Tue, Sep 18, 2001 at 09:12:31PM +0200, Frank Klemm wrote:
> On Tue, Sep 18, 2001 at 10:20:00AM -0700, Zack Weinberg wrote:
> > 
> > I'd also point out that very few people have access to the
> > standard; yes, ANSI sells copies for not-totally-outrageous sums,
> > but many don't know that and the cost may still be too high.
>
> Most programmers don't know the standard and are not interested in
> knowing the standard, because their (present) job is to solve a
> problem for one or two different systems, not for every
> theoretically possible system, and the standard supports nearly
> every stuff which has more than 4 pins ;-)

We tend to see things differently from most programmers, since we are
responsible for supporting every feature of the compiler.  The
standard is the only thing that tells us what the compiler is supposed
to do, and we have enough trouble with its own ambiguities.  Every
extension adds ambiguities to that.

We are therefore concerned that extensions fit well with the standard,
The best way to ensure that is for the people who propose and
implement them to be deeply familiar with the standard.  As such, it
is a problem that the standard is not freely or even widely available.

Let's get back to what you originally proposed.  You want to be able
to write 1000000 as 1_000_000 for legibility.  This would be easy to
implement and I agree that it would be an improvement.  What you need
to do is decide exactly what the extended syntax is supposed to be.
For instance, are you allowed to write any of the following?

	16777216_UL
	16777216U_L
	0._1234
	0x_1234
	12.34_e+56
	12.34e_+56

All but the last are legitimate "preprocessing numbers".  I can tell
you right now that I'll be a lot more receptive to an extension that
doesn't change the definition of a preprocessing number.

You should investigate the rules for numeric syntax in languages
which already have this notation, such as Ada and Perl.

Once you've done an exhaustive analysis and decided what your syntax
is going to be, you should submit a patch which implements and
documents the new extension.  We will then consider it.

Oh, and file your copyright assignment paperwork now; the turnaround
time can be several months and we can't take any nontrivial patch of
yours until it's come back.

> I'm looking for some webspace for feature proposals, performance
> issues and warning issues.
> 
> And someone who translates my "pseudo English" into "real English".

Please feel free to submit patches to our website.  (You need not file
copyright paperwork to do this.)  You can check it out of CVS with

cvs -d :pserver:anoncvs@gcc.gnu.org:/cvs/gcc co wwwdocs

Read through the existing htdocs/projects directory first, please.

There are plenty of native English speakers on this list who will be
happy to help you with phrasing and so on.

zw