1 ;;; tv-util.el --- support for Tai Viet -*- coding: utf-8 -*-
3 ;; Copyright (C) 2007, 2008
4 ;; National Institute of Advanced Industrial Science and Technology (AIST)
5 ;; Registration Number H13PRO009
7 ;; Keywords: multilingual, Tai Viet, i18n
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software; you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation; either version 3, or (at your option)
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs; see the file COPYING. If not, write to the
23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24 ;; Boston, MA 02110-1301, USA.
28 ;; Regexp matching with a sequence of Tai Viet characters.
30 (format "[\xaa80-\xaac2\xaadb-\xaadf-]+"))
32 ;; Char-table of information about glyph type of Tai Viet characters.
33 (defconst tai-viet-glyph-info
34 (let ((table (make-char-table nil))
35 (specials '((right-overhang . "ꪊꪋꪌꪍꪏꪓꪖꪜꪞꪡꪤꪨ")
37 (combining-vowel . "ꪴꪰꪲꪳꪷꪸꪾ")
38 (combining-tone . "꪿꫁")
40 ;; Set all TaiViet characters to `t'.
41 (set-char-table-range table (cons #xaa80 #xaac2) t)
42 (set-char-table-range table (cons #xaadb #xaadf) t)
43 ;; Overwrite it for special characters.
44 (dolist (elt specials)
45 (let ((category (car elt))
47 (dotimes (i (length chars))
48 (aset table (aref chars i) category))))
51 (defun tai-viet-compose-string (from to string)
52 "Compose Tai Viet characters in STRING between indices FROM and TO."
53 (let* ((ch (aref string from))
54 (info (aref tai-viet-glyph-info ch))
56 (if (eq info 'non-spacing)
57 (compose-string string from (1+ from) (string ch ?\t)))
58 (setq from (1+ from) prev-info info)
59 (while (and (< from to)
60 (>= #xaa80 (setq ch (aref string from)))
62 (setq info (aref tai-viet-glyph-info ch))
63 (if (and (eq info 'non-spacing)
64 (eq prev-info 'non-spacing))
65 (compose-string from (1+ from) (string ?\t ch)))
66 (setq from (1+ from) prev-info info))
67 (if (eq info 'right-overhang)
68 (compose-string string (1- from) from (string ch ?\t)))
71 (defun tai-viet-compose-region (from to)
72 "Compose Tai Viet characters in the region between FROM and TO."
73 (decompose-region from to)
74 (let ((normal-rule '(Br . Bl))
75 (tone-rule '(tr . bl))
77 ch info pos components overhang)
80 (setq ch (char-after from)
81 info (aref tai-viet-glyph-info ch)))
86 (if (memq info '(combining-vowel combining-tone))
88 ;; Display this as a spacing glyph.
89 (compose-region (1- from) from (string ?\t ch))
94 overhang (if (eq info 'right-overhang)
96 (if (and (not prev-viet) (eq info 'left-overhang))
101 (setq ch (char-after from)
102 info (aref tai-viet-glyph-info ch)))
103 (if (memq info '(combining-vowel combining-tone))
106 (list components normal-rule ch)
110 (setq ch (char-after from)
111 info (aref tai-viet-glyph-info ch))
112 (eq info 'combining-tone))
113 (setq components (nconc components
116 (if (eq overhang 'left-overhang)
117 (setq components (cons ?\t
118 (cons normal-rule components)))
119 (if (and (eq overhang 'right-overhang)
121 (setq components (nconc components
122 (list normal-rule ?\t)))))
123 (compose-region pos from components))
124 (if (eq overhang 'left-overhang)
125 (compose-region pos from (string ?\t components))))
126 (if (eq overhang 'left-overhang)
127 (compose-region pos from (string ?\t components))
128 (if (and (eq overhang 'right-overhang) (>= from to))
129 (compose-region pos from (string components ?\t))))))))
134 (defun tai-viet-composition-function (from to font-object string)
136 (if (string-match tai-viet-re string from)
137 (tai-viet-compose-string from (match-end 0) string))
139 (if (looking-at tai-viet-re)
140 (tai-viet-compose-region from (match-end 0)))))
143 (provide 'tai-viet-util)
145 ;; arch-tag: a45ac3fc-07d0-44d5-8841-2ebea7e11f5b