bug#56323: 29.0.50; [v2] Add new customisable phonetic Tamil input method

[Eli Zaretskii <eliz@gnu.org>]

> From: Visuwesh <visuweshm@gmail.com>
> Cc: 56323@debbugs.gnu.org
> Date: Sat, 02 Jul 2022 14:10:07 +0530
> 
> > The only remaining issue, AFAIU, is why string-lessp is not good
> > enough for sorting within each sub-list.
> 
> It is not good enough for each sub-list for the same reason: the order
> produced by string-lessp is not the same as the actual order.

So, then please explain what should be the "correct" order within each
sub-list.  Is the correct order within each sub-list in the ascending
order of the codepoint?  If not, what is the correct order?

> I will try to explain the situation using the regular English alphabets
> and the extra letter þ (which was used in place of "th" AFAIU).
> 
> The core English alphabets are a-z then we have some extra alphabets
> like the þ above.  When we have a list containing _both_ a-z and þ, the
> order produced by string-lessp is wrong.
> 
> When I did as you suggested and broke the list into two -- a-z and þ --
> and sorted the sub-list that only contained a-z with string-lessp, the
> sorted sub-list was not in the right alphabetical order i.e., instead of
> "a b c d ..." it was "a c b d ..."

That's not what I see:

  (let ((letters '("a" "b" "r" "x" "z")))
    (sort letters 'string-lessp))
   => ("a" "b" "r" "x" "z")

Please show an example where characters a-z are sorted by string-lessp
in the wrong order.