Subject: Re: bug#58957: [PATCH] Improve Brahmi composition rules.

From: समीर सिंह Sameer Singh<[email-masked]>
Date: Wed, 2 Nov 2022 08:14:09 +0530

On Wed, Nov 2, 2022 at 8:12 AM समीर सिंह Sameer Singh <[email-masked]>
wrote:

> The present composition rules for Brahmi have a bug where the virama is
> not composed with the consonants, I have fixed that now. I have also added
> support for composing velar and bilabial fricatives in Brahmi.
>
> Please review the patch.
> Thanks
>
From 0c4329edef9577d808e0a9c6d87b9e08e3b96356 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E0=A4=B8=E0=A4=AE=E0=A5=80=E0=A4=B0=20=E0=A4=B8=E0=A4=BF?=
 =?UTF-8?q?=E0=A4=82=E0=A4=B9=20Sameer=20Singh?= <[email-masked]>
Date: Wed, 2 Nov 2022 08:05:44 +0530
Subject: [PATCH] * lisp/language/indian.el: Improve Brahmi composition rules.
 (bug#58957)

---
 lisp/language/indian.el | 42 ++++++++++++++++++++++++++++-------------
 1 file changed, 29 insertions(+), 13 deletions(-)

diff --git a/lisp/language/indian.el b/lisp/language/indian.el
index 4994cfdc7a..f70f7fcce1 100644
--- a/lisp/language/indian.el
+++ b/lisp/language/indian.el
@@ -552,24 +552,40 @@ malayalam-composable-pattern
    char-script-table))
 
 ;; Brahmi composition rules
-(let ((consonant     "[\U00011013-\U00011034]")
-      (non-consonant "[^\U00011013-\U00011034\U00011046\U0001107F]")
-      (vowel         "[\U00011038-\U00011045]")
-      (numeral       "[\U00011052-\U00011065]")
-      (multiplier    "[\U00011064\U00011065]")
-      (virama        "\U00011046")
-      (number-joiner "\U0001107F"))
+(let ((consonant            "[\x11013-\x11037\x11075]")
+      (independent-vowel    "[\x11005-\x11012\x11071\x11072]")
+      (vowel                "[\x11038-\x11045\x11073\x11074]")
+      (nasal                "[\x11000\x11001]")
+      (virama               "\x11046")
+      (jivhamuliya          "\x11003")
+      (upadhmaniya          "\x11004")
+      (ka-kha               "[\x11013\x11014]")
+      (pa-pha               "[\x11027\x11028]")
+      (number-joiner        "\x1107F")
+      (numeral              "[\x11052-\x11065]")
+      (multiplier           "[\x11064\x11065]"))
   (set-char-table-range composition-function-table
-		        '(#x11046 . #x11046)
+                        '(#x11046 . #x11046)
                         (list (vector
-                               ;; Consonant conjuncts
-                               (concat consonant "\\(?:" virama consonant "\\)+"
-                                       vowel "?")
+                               ;; Consonant based syllables
+                               (concat consonant "\\(?:" virama consonant
+                                       "\\)*\\(?:" virama "\\|" vowel "*"
+                                       nasal "?\\)")
                                1 'font-shape-gstring)
                               (vector
-                               ;; Vowelless consonants
-                               (concat consonant virama non-consonant)
+                               ;; Vowel based syllables
+                               (concat independent-vowel virama "?" vowel "?" nasal "?")
                                1 'font-shape-gstring)))
+  (set-char-table-range composition-function-table
+                        '(#x11003 . #x11004)
+                        (list (vector
+                               ;; Velar fricative
+                               (concat jivhamuliya ka-kha "?")
+                               0 'font-shape-gstring)
+                              (vector
+                               ;; Bilabial fricative
+                               (concat upadhmaniya pa-pha "?")
+                               0 'font-shape-gstring)))
   (set-char-table-range composition-function-table
                         '(#x1107F . #x1107F)
                         (list (vector
-- 
2.37.3