lisp/language/indian.el

   1 ;;; indian.el --- Indian languages support -*- coding: iso-2022-7bit; -*-
   2
   3 ;; Copyright (C) 1997, 1999, 2001, 2002, 2003, 2004, 2005, 2006, 2007
   4 ;;   Free Software Foundation, Inc.
   5 ;; Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007
   6 ;;   National Institute of Advanced Industrial Science and Technology (AIST)
   7 ;;   Registration Number H14PRO021
   8
   9 ;; Maintainer:  KAWABATA, Taichi <kawabata@m17n.org>
  10 ;; Keywords:    multilingual, i18n, Indian
  11
  12 ;; This file is part of GNU Emacs.
  13
  14 ;; GNU Emacs is free software; you can redistribute it and/or modify
  15 ;; it under the terms of the GNU General Public License as published by
  16 ;; the Free Software Foundation; either version 2, or (at your option)
  17 ;; any later version.
  18
  19 ;; GNU Emacs is distributed in the hope that it will be useful,
  20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 ;; GNU General Public License for more details.
  23
  24 ;; You should have received a copy of the GNU General Public License
  25 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  26 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  27 ;; Boston, MA 02110-1301, USA.
  28
  29 ;;; Commentary:
  30
  31 ;; This file defines in-is13194 coding system and relationship between
  32 ;; indian-glyph character-set and various CDAC fonts.
  33
  34 ;;; Code:
  35
  36 (define-coding-system 'in-is13194-devanagari
  37   "8-bit encoding for ASCII (MSB=0) and IS13194-Devanagari (MSB=1)."
  38   :coding-type 'iso-2022
  39   :mnemonic ?D
  40   :designation [ascii indian-is13194 nil nil]
  41   :charset-list '(ascii indian-is13194)
  42   :post-read-conversion 'in-is13194-post-read-conversion
  43   :pre-write-conversion 'in-is13194-pre-write-conversion)
  44
  45 (define-coding-system-alias 'devanagari 'in-is13194-devanagari)
  46
  47 (defvar indian-font-foundry 'cdac
  48   "Font foundry for Indian characters.
  49 Currently supported foundries are `cdac' and `akruti'.")
  50
  51 (defvar indian-script-language-alist
  52   '((devanagari (hindi sanskrit) nil)
  53     (bengali (bengali assamese) nil)
  54     (gurmukhi (punjabi) nil)
  55     (gujarati (gujarati) nil)
  56     (oriya (oriya) nil)
  57     (tamil (tamil) nil)
  58     (telugu (telugu) nil)
  59     (kannada (kannada) nil)
  60     (malayalam (malayalam) nil))
  61   "Alist of Indian scripts vs the corresponding language list and font foundry.
  62 Each element has this form:
  63
  64   (SCRIPT LANGUAGE-LIST FONT-FOUNDRY)
  65
  66 SCRIPT is one of Indian script names.
  67
  68 LANGUAGE-LIST is a list of Indian langauge names SCRIPT is used for.
  69 The list is in the priority order.
  70
  71 FONT-FOUNDRY is a font foundry representing a group of Indian
  72 fonts.  If the value is nil, the value of `indian-font-foundry'
  73 is used.")
  74
  75 (defconst indian-font-char-index-table
  76   '(                                    ; for which language(s)
  77     ;; CDAC fonts
  78     (#x0000 . cdac:dv-ttsurekh)         ; hindi, etc
  79     (#x0100 . cdac:sd-ttsurekh)         ; sanskrit
  80     (#x0200 . cdac:bn-ttdurga)          ; bengali
  81     (#x0300 . cdac:tm-ttvalluvar)       ; tamil
  82     (#x0400 . cdac:tl-tthemalatha)      ; telugu
  83     (#x0500 . cdac:as-ttdurga)          ; assamese
  84     (#x0600 . cdac:or-ttsarala)         ; oriya
  85     (#x0700 . cdac:kn-ttuma)            ; kannada
  86     (#x0800 . cdac:ml-ttkarthika)       ; malayalam
  87     (#x0900 . cdac:gj-ttavantika)       ; gujarati
  88     (#x0A00 . cdac:pn-ttamar)           ; punjabi
  89
  90     ;; AKRUTI fonts
  91     (#x0B00 . akruti:dev)               ; hindi, etc
  92     (#x0C00 . akruti:bng)               ; bengali
  93     (#x0D00 . akruti:pnj)               ; punjabi
  94     (#x0E00 . akruti:guj)               ; gujarati
  95     (#x0F00 . akruti:ori)               ; oriya
  96     (#x1000 . akruti:tml)               ; tamil
  97     (#x1100 . akruti:tlg)               ; telugu
  98     (#x1200 . akruti:knd)               ; kannada
  99     (#x1300 . akruti:mal)               ; malayalam
 100     )
 101   "Alist of indices of `indian-glyph' character vs Indian font identifiers.
 102 Each element has this form: (INDEX . FONT-IDENTIFIER)
 103
 104 INDEX is an index number of the first character in the charset
 105 `indian-glyph' assigned for glyphs in the font specified by
 106 FONT-IDENTIFIER.  Currently FONT-IDENTIFIERs are defined for CDAC
 107 and AKRUTI font groups.")
 108
 109 (defun indian-font-char (index font-identifier)
 110   "Return character of charset `indian-glyph' made from glyph index INDEX.
 111 FONT-IDENTIFIER is an identifier of an Indian font listed in the
 112 variable `indian-font-char-index-table'.  It specifies which
 113 font INDEX is for."
 114   (if (or (< index 0) (> index 255))
 115       (error "Invalid glyph index: %d" index))
 116   (let ((start (car (rassq font-identifier indian-font-char-index-table))))
 117     (if (not start)
 118         (error "Unknown font identifier: %s" font-identifier))
 119     (setq index (+ start index))
 120     (make-char 'indian-glyph (+ (/ index 96) 32) (+ (% index 96) 32))))
 121
 122 ;; Return a range of characters (cons of min and max character) of the
 123 ;; charset `indian-glyph' for displaying SCRIPT in LANGUAGE by a font
 124 ;; of FOUNDRY.
 125
 126 (defun indian-font-char-range (font-identifier)
 127   (cons (indian-font-char 0 font-identifier)
 128         (indian-font-char 255 font-identifier)))
 129
 130 (defvar indian-script-table
 131   '[
 132     devanagari
 133     sanskrit
 134     bengali
 135     tamil
 136     telugu
 137     assamese
 138     oriya
 139     kannada
 140     malayalam
 141     gujarati
 142     punjabi
 143     ]
 144   "Vector of Indian script names.")
 145
 146 (let ((len (length indian-script-table))
 147       (i 0))
 148   (while (< i len)
 149     (put (aref indian-script-table i) 'indian-glyph-code-offset (* 256 i))
 150     (setq i (1+ i))))
 151
 152 (defvar indian-default-script 'devanagari
 153   "Default script for Indian languages.
 154 Each Indian language environment sets this value
 155 to one of `indian-script-table' (which see).
 156 The default value is `devanagari'.")
 157
 158 (defvar indian-composable-pattern
 159   (make-char-table nil)
 160   "Char table of regexps for composable Indian character sequence.")
 161
 162 (provide 'indian)
 163
 164 ;;; arch-tag: 83aa8fc7-7ee2-4364-a6e5-498f5e3b8c2f
 165 ;;; indian.el ends here