Re: Accessing the environment's locale encoding settings

[ludo@gnu.org (Ludovic Courtès)]

Hi,

Apologies for not answering earlier, and for making changes without
continuing this discussion.  So here’s an after-the-fact reply.

Mark H Weaver <mhw@netris.org> skribis:

> ludo@gnu.org (Ludovic Courtès) writes:
>> It’s not completely satisfying either because --locale is not in
>> 2.0.[0-3], so users who really need it will need some configury;
>> furthermore, from 2.2.x on, it will be mostly unneeded.
>>
>> Yet, a choice has to be made between this hack and the other one.  :-)
>>
>> Thoughts?
>
> I like the --locale argument, except that the default (if there is no
> --locale argument) should be to either (A) call setlocale(LC_ALL, "") or
> (B) do something like the other hack, where the arguments are decoded as
> if the locale had been temporarily set according to the environment
> variables.
>
> My strong preference would be Option A.

The problem I see with changing the default to call setlocale(LC_ALL,
"") is that %default-port-encoding would no longer match the current
locale, as is currently the case.  Or we’d have to change its default
value.  But I thought this would be too disruptive in either case, and
thus I stick to Option B.

> If you are trying to maintain backward compatibility, keep in mind that
> for most practical purposes, Guile 1.8 acts closer to option A than the
> other options.  Furthermore, Option A is the Right Thing moving forward,
> and matches what Guile 2.2 will do.
>
> If we accept only ASCII arguments by default, then _most_ Guile scripts
> will need to add the --locale argument, but only for versions after
> 2.0.3.  More likely, many authors won't bother with this ugliness, and
> their scripts will be broken for non-ASCII locales.

Yes, I thought about that too, and thought it counted against Option A.

So the current situation is:

  • In 2.0, one still has to call ‘setlocale’ implicitly, but
    command-line arguments are converted from the locale encoding
    suggested by the environment variables (commit
    ed4c3739668b4b111b38555b8bc101cb74c87c1c).

  • In 2.1, the ‘setlocale’ call is implicit when the ‘guile’ executable
    is used (commit bb9b357e2b98cea82f844115ee5f66704bb6a1c8).  The
    %default-port-encoding value is still Latin-1, but presumably that
    would need to be changed to the current locale encoding.  Thoughts?

Nothing’s set in stone and I’m glad to revisit the situation.

Thanks,
Ludo’.