code.delx.au - gnu-emacs/blob - lisp/language/indian.el

   1 ;;; indian.el --- Indian languages support -*- coding: iso-2022-7bit; -*-
   2
   3 ;; Copyright (C) 1999, 2001 Free Software Foundation, Inc.
   4
   5 ;; Maintainer:  KAWABATA, Taichi <kawabata@m17n.org>
   6 ;; Keywords:    multilingual, i18n, Indian
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Commentary:
  26
  27 ;; This file defines in-is13194 coding system and relationship between
  28 ;; indian-glyph character-set and various CDAC fonts.
  29
  30 ;;; Code:
  31
  32 (define-coding-system 'in-is13194-devanagari
  33   "8-bit encoding for ASCII (MSB=0) and IS13194-Devanagari (MSB=1)."
  34   :coding-type 'iso-2022
  35   :mnemonic ?D
  36   :designation [ascii indian-is13194 nil nil]
  37   :charset-list '(ascii indian-is13194)
  38   :post-read-conversion 'in-is13194-post-read-conversion
  39   :pre-write-conversion 'in-is13194-pre-write-conversion)
  40
  41 (define-coding-system-alias 'devanagari 'in-is13194-devanagari)
  42
  43 (defvar indian-font-foundry 'cdac
  44   "Font foundry for Indian characters.
  45 Currently supported foundries are `cdac' and `akruti'.")
  46
  47 (defvar indian-script-language-alist
  48   "Alist of Indian scripts vs the corresponding language list and font foundry.
  49 Each element has this form:
  50
  51   (SCRIPT LANGUAGE-LIST FONT-FOUNDRY)
  52
  53 SCRIPT is one of Indian script names.
  54
  55 LANGUAGE-LIST is a list of Indian langauge names SCRIPT is used for.
  56 The list is in the priority order.
  57
  58 FONT-FOUNDRY is a font foundry representing a group of Indian
  59 fonts.  If the value is nil, the value of `indian-font-foundry'
  60 is used."
  61   '((devanagari (hindi sanskrit) nil)
  62     (bengali (bengali assamese) nil)
  63     (gurmukhi (punjabi) nil)
  64     (gujarati (gujarati) nil)
  65     (oriya (oriya) nil)
  66     (tamil (tamil) nil)
  67     (telugu (telugu) nil)
  68     (kannada (kannada) nil)
  69     (malayalam (malayalam) nil)))
  70
  71 (defconst indian-font-char-index-table
  72   '(                                    ; for which language(s)
  73     ;; CDAC fonts
  74     (#x0000 . cdac:dv-ttsurekh)         ; hindi, etc
  75     (#x0100 . cdac:sd-ttsurekh)         ; sanskrit
  76     (#x0200 . cdac:bn-ttdurga)          ; bengali
  77     (#x0300 . cdac:tm-ttvalluvar)       ; tamil
  78     (#x0400 . cdac:tl-tthemalatha)      ; telugu
  79     (#x0500 . cdac:as-ttdurga)          ; assamese
  80     (#x0600 . cdac:or-ttsarala)         ; oriya
  81     (#x0700 . cdac:kn-ttuma)            ; kannada
  82     (#x0800 . cdac:ml-ttkarthika)       ; malayalam
  83     (#x0900 . cdac:gj-ttavantika)       ; gujarati
  84     (#x0A00 . cdac:pn-ttamar)           ; punjabi
  85
  86     ;; AKRUTI fonts
  87     (#x0B00 . akruti:dev)               ; hindi, etc
  88     (#x0C00 . akruti:bng)               ; bengali
  89     (#x0D00 . akruti:pnj)               ; punjabi
  90     (#x0E00 . akruti:guj)               ; gujarati
  91     (#x0F00 . akruti:ori)               ; oriya
  92     (#x1000 . akruti:tml)               ; tamil
  93     (#x1100 . akruti:tlg)               ; telugu
  94     (#x1200 . akruti:knd)               ; kannada
  95     (#x1300 . akruti:mal)               ; malayalam
  96     )
  97   "Aliat of indices of `indian-glyph' character vs Indian font identifiers.
  98 Each element has this form: (INDEX . FONT-IDENTIFIER)
  99
 100 INDEX is an index number of the first character in the charset
 101 `indian-glyph' assigned for glyphs in the font specified by
 102 FONT-IDENTIFIER.  Currently FONT-IDENTIFIERs are defined for CDAC
 103 and AKRUTI font groups.")
 104
 105 (defun indian-font-char (index font-identifier)
 106   "Return character of charset `indian-glyph' made from glyph index INDEX.
 107 FONT-IDENTIFIER is an identifier of an Indian font listed in the
 108 variable `indian-font-char-index-table'.  It specifies which
 109 font INDEX is for."
 110   (if (or (< index 0) (> index 255))
 111       (error "Invalid glyph index: %d" index))
 112   (let ((start (car (rassq font-identifier indian-font-char-index-table))))
 113     (if (not start)
 114         (error "Unknown font identifier: %s" font-identifier))
 115     (setq index (+ start index))
 116     (make-char 'indian-glyph (+ (/ index 96) 32) (+ (% index 96) 32))))
 117
 118 ;; Return a range of characters (cons of min and max character) of the
 119 ;; charset `indian-glyph' for displaying SCRIPT in LANGUAGE by a font
 120 ;; of FOUNDRY.
 121
 122 (defun indian-font-char-range (font-identifier)
 123   (cons (indian-font-char 0 font-identifier)
 124         (indian-font-char 255 font-identifier)))
 125
 126 (defvar indian-script-table
 127   '[
 128     devanagari
 129     sanskrit
 130     bengali
 131     tamil
 132     telugu
 133     assamese
 134     oriya
 135     kannada
 136     malayalam
 137     gujarati
 138     punjabi
 139     ]
 140   "Vector of Indian script names.")
 141
 142 (let ((len (length indian-script-table))
 143       (i 0))
 144   (while (< i len)
 145     (put (aref indian-script-table i) 'indian-glyph-code-offset (* 256 i))
 146     (setq i (1+ i))))
 147
 148 (defvar indian-default-script 'devanagari
 149   "Default script for Indian languages.
 150 Each Indian language environment sets this value
 151 to one of `indian-script-table' (which see).
 152 The default value is `devanagari'.")
 153
 154 (defvar indian-composable-pattern
 155   (make-char-table nil)
 156   "Char table of regexps for composable Indian character sequence.")
 157
 158 (provide 'indian)
 159
 160 ;;; indian.el ends here