Re: [PATCH] Add the Kaithi script to Emacs

[Eli Zaretskii <eliz@gnu.org>]

> From: समीर सिंह Sameer Singh
>  <lumarzeli30@gmail.com>
> Date: Sat, 7 May 2022 02:32:06 +0530
> 
> I have added the Kaithi script this time.
> Please check for any mistakes

Thanks.

> diff --git a/etc/HELLO b/etc/HELLO
> index dbbcc0493b..351e2dc4cd 100644
> --- a/etc/HELLO
> +++ b/etc/HELLO
> @@ -59,6 +59,8 @@ Hindi (हिंदी)	नमस्ते / नमस्कार ।
>  Inuktitut (ᐃᓄᒃᑎᑐᑦ)	ᐊᐃ
>  Italian (italiano)	Ciao / Buon giorno
>  Javanese (ꦧꦱꦗꦮꦶ)	console.log("ꦲꦭꦺꦴ");
> +
> +Kaithi (𑂍𑂶𑂟𑂲)                              𑂩𑂰𑂧𑂩𑂰𑂧

The text in parenthesis should be the name of the script spelled in
the script itself, followed by a single TAB, and then one or more
greetings in language(s) that use(s) the script.  Does the above
follow this pattern?  I see that you used spaces instead of TAB, which
is incorrect.

> +*** New language environment "Kaithi".
> +This language environment supports Kaithi or Kayasthi, which was
> +an important writing system of the past mainly used for administrative
> +purposes. A new input method, 'kaithi', is provided to type text in

Please leave 2 spaces between sentences in documentation, per US
English rules we use.

> diff --git a/lisp/international/fontset.el b/lisp/international/fontset.el
> index 883f08905e..5bfa085b1b 100644
> --- a/lisp/international/fontset.el
> +++ b/lisp/international/fontset.el
> @@ -232,6 +232,7 @@ font-encoding-charset-alist
>  	(elymaic #x10FE0)
>  	(old-uyghur #x10F70)
>          (brahmi #x11013 #x11045 #x11052 #x11065)
> +        (kaithi #x1108D)

Is a single character enough to accept a font as having good coverage
of Kaithi?  If not, you can request more than one, like I did for
Brahmi.

> @@ -599,6 +600,7 @@ setup-default-fontset
>       (sinhala ,(font-spec :registry "iso10646-1" :otf '(sinh nil (akhn))))
>       (malayalam ,(font-spec :registry "iso10646-1" :otf '(mlm2 nil (akhn)))
>                  ,(font-spec :registry "iso10646-1" :otf '(mlym nil (akhn))))
> +     (kaithi ,(font-spec :registry "iso10646-1" :otf '(kthi nil (rphf))))

Is the rphf feature indeed needed for Kaithi?  If not, just add kaithi
to the list of "simple scripts" that starts around line 736 in
fontset.el, and the code there will do the rest.

> +            (documentation . "\
> +Such languages which used Kaithi script such as Awadhi, Bhojpuri, Magahi and
> +Maithili are supported in this language environment."))

"Such languages ... such as" is awkward English; please rephrase this
doc string.

> +  (set-char-table-range composition-function-table
> +                        '(#x110B0 . #x110BA)
> +                        (list (vector
> +                               (concat consonant nukta "?\\(?:" virama consonant nukta "?\\)*\\(?:" virama "\\|" vowel "*" nukta "?" anusvara-candrabindu "?\\)")

Please break and reindent this long line to make it more readable.

> +("`c" #x200C)  ; ZWNJ
> +("`C" #x200D)  ; ZWJ

Are these zero-width characters used for writing in Kaithi?  If so,
should the composition rules be augmented with some rules that
mentions them?  At least ZWJ, if it has any role, should probably be
mentioned; ZWNJ most probably does its job by just being there and
preventing the other composition rules from taking effect.

Thanks.