Re: bug#47885: [PATCH] org-table-import: Make it more smarter for interactive use

[Maxim Nikulin]

It seems, there is no reliable way to work with numbers in a 
locale-aware way in emacs.  I am still against hard-coded list of 
locales. Requirement to customize a variable is rather inconvenient. 
Considering such properties as a part of translation is a little better 
but I prefer to avoid it.

The question may be risen in emacs-devel but I am unsure if I will 
participate in discussion.

On 18/05/2021 17:24, Utkarsh Singh wrote:
> On 2021-05-16, 23:24 +0700, Maxim Nikulin wrote:
>
> > On 14/05/2021 21:54, Utkarsh Singh wrote:
> > > On 2021-05-13, 00:08 +0700, Maxim Nikulin wrote:
> > >
> > > > Comma is decimal separator for es_ES, de_DE, ru_RU, etc. The point is
> > > > that order in which separator candidates are tried should depend on
> > > > active locale.
> > > I am willing to work on this problem but before this can you identify
> > > any other locale with similar problem or a resource from where I can
> > > information's about locale.
> >
> > I do not think list of locales should be hard coded. I am not familiar
> > with elisp enough to tell you if locale properties such as decimal
> > separator are exposed through some function. I expect, it is quite
> > probable. As a last measure, some number, e.g. 0.5 or 1.5 could be
> > formatted using a locale-aware function and result string could be
> > checked if it contains ",".
>
> Can you test this function:
>
> (defun org-table--comma-as-decimal-sep ()
>    "Return nil or 2 if separator is dot or comma respectively."
>    (string-search "," (format "%f" 10)))

No, it does not work. `format' always uses dot. It is reasonable when 
e.g. during writing a config file or during data exchange when locales 
must be ignored.

I was too optimistic. I did not expect that support of locales are so 
poor in Emcacs. I do not see any traces of localeconv(3) in sources that 
would allow to get value of decimal_point directly.

Numbers are forced to use "C" locale and I have not noticed any way to 
override it. Initial settings:

http://git.savannah.gnu.org/cgit/emacs.git/tree/src/emacs.c#n1490

http://git.savannah.gnu.org/cgit/emacs.git/tree/src/emacs.c#n2861

setlocale (LC_NUMERIC, "C");

> To test I am using:
> $ LANG=de_DE.UTF-8 emacs -Q
>
> But I am getting this as warning:
> (process:1787): Gtk-WARNING **: 15:40:49.375: Locale not supported by C library.
>         Using the fallback 'C' locale.

You get this error due to you have not generated this locale. On debian 
& ubuntu

dpkg-reconfigure locales

allows to select desired locales and performs all necessary actions.