Re: L10N & LC variables

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 27 May 2017 08:33:59 +0100
> From: Alan Third <alan@idiocy.org>
> Cc: emacs-devel <emacs-devel@gnu.org>
> 
> LANG is used in set-locale-environment in mule-cmds.el, but I don’t
> know what is set using it.

The doc string of set-locale-environment says quite a lot about that:

  This sets the language environment, the coding system priority,
  the default input method and sometimes other things.

> I know almost nothing about locales in emacs.

They are mainly used for setting up the defaults for encoding and
decoding incoming/outgoing text outside of Emacs.

> The main motivation for setting LANG on macOS was so that external
> commands would be given the correct locale, eg. spell checkers.

Spell-checking uses this to tell the speller what dictionary to use.

> Would it be worth creating a function available from lisp that returns
> system locale information?

What information would that function return?  Does "C-h L" do what you
want?  If not, what is missing?

Anyway, I think we should separate the issues related to translation
infrastructure from issues related to setting the language for
fetching strings translated into that language.  They are two
orthogonal problems; in particular, I can easily envision an Emacs
user wishing to set a language that has nothing to do with the user's
locale, for example to test some translations.  Also, the notion of
"current language" has implications elsewhere in Emacs, like in case
conversions.

We should handle these two classes of issues separately.