emacs/lisp/language/tibet-util.el

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;;; tibet-util.el --- utilities for Tibetan -*- coding: utf-8-emacs; lexical-binding: t; -*-
;; Copyright (C) 1997, 2001-2024 Free Software Foundation, Inc.
;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
;; 2005, 2006, 2007, 2008, 2009, 2010, 2011
;; National Institute of Advanced Industrial Science and Technology (AIST)
;; Registration Number H14PRO021
;; Author: Toru TOMABECHI <Toru.Tomabechi@orient.unil.ch>
;; Keywords: multilingual, Tibetan
;; Created: Feb. 17. 1997
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; History:
;; 1997.03.13 Modification in treatment of text properties;
;; Support for some special signs and punctuation.
;; 1999.10.25 Modification for a new composition way by K.Handa.
;;; Commentary:
;; Note: This file includes several codepoints outside of the Unicode
;; 0..#x10FFFF range, which are characters that were not unified into
;; Unicode. Therefore, this file is encoded in utf-8-emacs, because
;; UTF-8 cannot encode such codepoints. We include these codepoints
;; literally in the file to have them displayed by suitable fonts,
;; which makes maintenance easier.
;;; Code:
(defconst tibetan-obsolete-glyphs
`(("" . "") ; 2 col <-> 1 col
("" . "")
("" . "")
("" . "")
("ཿ" . "ཿ")
("" . "")
("" . "")
;; Yes these are dirty. But ...
("༎ ༎" . ,(compose-string (copy-sequence "༎ ༎")
0 3 [?༎ (Br . Bl) ? (Br . Bl) ?༎]))
("༄༅༅" . ,(compose-string
(copy-sequence "࿁࿂࿂࿂") 0 4
[?࿁ (Br . Bl) ?࿂ (Br . Bl) ?࿂ (Br . Bl) ?࿂]))
("༄༅" . ,(compose-string (copy-sequence "࿁࿂࿂")
0 3 [?࿁ (Br . Bl) ?࿂ (Br . Bl) ?࿂]))
("" . ,(compose-string (copy-sequence "࿁࿂༙")
0 3 [?࿁ (Br . Bl) ?࿂ (br . tr) ?༙]))
("" . ,(compose-string (copy-sequence "࿁࿂")
0 2 [?࿁ (Br . Bl) ?࿂]))))
;;;###autoload
(defun tibetan-char-p (ch)
"Check if char CH is Tibetan character.
Returns non-nil if CH is Tibetan. Otherwise, returns nil."
(memq (char-charset ch) '(tibetan tibetan-1-column)))
;;; Functions for Tibetan <-> Tibetan-transcription.
;;;###autoload
(defun tibetan-tibetan-to-transcription (str)
"Transcribe Tibetan string STR and return the corresponding Roman string."
(let (;; Accumulate transcriptions here in reverse order.
(trans nil)
(len (length str))
(i 0)
ch this-trans)
(while (< i len)
(let ((idx (string-match tibetan-precomposition-rule-regexp str i)))
(if (eq idx i)
;; Ith character and the followings matches precomposable
;; Tibetan sequence.
(setq i (match-end 0)
this-trans
(car (rassoc
(cdr (assoc (match-string 0 str)
tibetan-precomposition-rule-alist))
tibetan-precomposed-transcription-alist)))
(setq ch (substring str i (1+ i))
i (1+ i)
this-trans
(car (or (rassoc ch tibetan-consonant-transcription-alist)
(rassoc ch tibetan-vowel-transcription-alist)
(rassoc ch tibetan-subjoined-transcription-alist)))))
(setq trans (cons this-trans trans))))
(apply 'concat (nreverse trans))))
;;;###autoload
(defun tibetan-transcription-to-tibetan (str)
"Convert Tibetan Roman string STR to Tibetan character string.
The returned string has no composition information."
(let (;; Case is significant.
(case-fold-search nil)
(idx 0)
;; Accumulate Tibetan strings here in reverse order.
(t-str-list nil)
i subtrans)
(while (setq i (string-match tibetan-regexp str idx))
(if (< idx i)
;; STR contains a pattern that doesn't match Tibetan
;; transcription. Include the pattern as is.
(setq t-str-list (cons (substring str idx i) t-str-list)))
(setq subtrans (match-string 0 str)
idx (match-end 0))
(let ((t-char (cdr (assoc subtrans
tibetan-precomposed-transcription-alist))))
(if t-char
;; SUBTRANS corresponds to a transcription for
;; precomposable Tibetan sequence.
(setq t-char (car (rassoc t-char
tibetan-precomposition-rule-alist)))
(setq t-char
(cdr
(or (assoc subtrans tibetan-consonant-transcription-alist)
(assoc subtrans tibetan-vowel-transcription-alist)
(assoc subtrans tibetan-modifier-transcription-alist)
(assoc subtrans tibetan-subjoined-transcription-alist)))))
(setq t-str-list (cons t-char t-str-list))))
(if (< idx (length str))
(setq t-str-list (cons (substring str idx) t-str-list)))
(apply 'concat (nreverse t-str-list))))
;;
;;; Functions for composing/decomposing Tibetan sequence.
;;
;; A Tibetan syllable is typically structured as follows:
;;
;; [Prefix] C [C+] V [M] [Suffix [Post suffix]]
;;
;; where C's are all vertically stacked, V appears below or above
;; consonant cluster and M is always put above the C[C+]V combination.
;; (Sanskrit visarga, though it is a vowel modifier, is considered
;; to be a punctuation.)
;;
;; Here are examples of the words "bsgrubs" and "hfauM"
;;
;; བསྒྲུབས ཧཱུཾ
;;
;; M
;; b s b s h
;; g fa
;; r u
;; u
;;
;; Consonants `'' (འ), `w' (ཝ), `y' (ཡ), `r' (ར) take special
;; forms when they are used as subjoined consonant. Consonant `r'
;; takes another special form when used as superjoined in such a case
;; as "rka", while it does not change its form when conjoined with
;; subjoined `'', `w' or `y' as in "rwa", "rya".
; Append a proper composition rule and glyph to COMPONENTS to compose
; CHAR with a composition that has COMPONENTS.
(defun tibetan-add-components (components char)
(let ((last (last components))
(stack-upper '(tc . bc))
(stack-under '(bc . tc))
rule comp-vowel)
;; Special treatment for 'a chung.
;; If 'a follows a consonant, turn it into the subjoined form.
;; * Disabled by Tomabechi 2000/06/09 *
;; Because in Unicode, འ may follow directly a consonant without
;; any intervening vowel, as in མཁ<E0BD98><E0BD81><EFBFBD><EFBFBD>འ་=མ ཁ འ not མ ཁ <20><><EFBFBD><EFBFBD>
;;(if (and (= char ?འ)
;; (aref (char-category-set (car last)) ?0))
;; (setq char ?ཱ)) ;; modified for new font by Tomabechi 1999/12/10
;; Composite vowel signs are decomposed before being added
;; Added by Tomabechi 2000/06/08
(if (memq char '(?ཱི ?ཱུ ?ྲྀ ?ཷ ?ླྀ ?ཹ ?ཱྀ))
(setq comp-vowel
(copy-sequence
(cddr (assoc (char-to-string char)
tibetan-composite-vowel-alist)))
char
(cadr (assoc (char-to-string char)
tibetan-composite-vowel-alist))))
(cond
;; Compose upper vowel sign vertically over.
((aref (char-category-set char) ?2)
(setq rule stack-upper))
;; Compose lower vowel sign vertically under.
((aref (char-category-set char) ?3)
(if (or (eq char ?<3F><EFBFBD><EFBFBD><EFBFBD>) ;; `<60><><EFBFBD><EFBFBD>' and `཰' should not visible when composed.
(eq char #xF70))
(setq rule nil)
(setq rule stack-under)))
;; Transform ra-mgo (superscribed r) if followed by a subjoined
;; consonant other than w, ', y, r.
((and (= (car last) ?ར)
(not (memq char '(?ྭ ?ཱ ?ྱ ?ྲ))))
(setcar last ?<3F><EFBFBD><EFBFBD><EFBFBD>) ;; modified for newfont by Tomabechi 1999/12/10
(setq rule stack-under))
;; Transform initial base consonant if followed by a subjoined
;; consonant but 'a.
(t
(let ((laststr (char-to-string (car last))))
(if (and (/= char ?ཱ) ;; modified for new font by Tomabechi
(string-match "[ཀ-ཛྷཞཟལ-ཀྵཪ]" laststr))
(setcar last (string-to-char
(cdr (assoc (char-to-string (car last))
tibetan-base-to-subjoined-alist)))))
(setq rule stack-under))))
(if rule
(setcdr last (list rule char)))
;; Added by Tomabechi 2000/06/08
(if comp-vowel
(nconc last comp-vowel))
))
;;;###autoload
(defun tibetan-compose-string (str)
"Compose Tibetan string STR."
(let ((idx 0))
;; `འ' is included in the pattern for subjoined consonants
;; because we treat it specially in tibetan-add-components.
;; (This feature is removed by Tomabechi 2000/06/08)
(while (setq idx (string-match tibetan-composable-pattern str idx))
(let ((from idx)
(to (match-end 0))
components)
(if (eq (string-match tibetan-precomposition-rule-regexp str idx) idx)
(setq idx (match-end 0)
components
(list (string-to-char
(cdr
(assoc (match-string 0 str)
tibetan-precomposition-rule-alist)))))
(setq components (list (aref str idx))
idx (1+ idx)))
(while (< idx to)
(tibetan-add-components components (aref str idx))
(setq idx (1+ idx)))
(compose-string str from to components))))
str)
;;;###autoload
(defun tibetan-compose-region (beg end)
"Compose Tibetan text the region BEG and END."
(interactive "r")
;; (let (str result chars)
(save-excursion
(save-restriction
(narrow-to-region beg end)
(goto-char (point-min))
;; `འ' is included in the pattern for subjoined consonants
;; because we treat it specially in tibetan-add-components.
;; (This feature is removed by Tomabechi 2000/06/08)
(while (re-search-forward tibetan-composable-pattern nil t)
(let ((from (match-beginning 0))
(to (match-end 0))
components)
(goto-char from)
(if (looking-at tibetan-precomposition-rule-regexp)
(progn
(setq components
(list (string-to-char
(cdr
(assoc (match-string 0)
tibetan-precomposition-rule-alist)))))
(goto-char (match-end 0)))
(setq components (list (char-after from)))
(forward-char 1))
(while (< (point) to)
(tibetan-add-components components (following-char))
(forward-char 1))
(compose-region from to components)))))) ;; )
(defvar tibetan-decompose-precomposition-alist
(mapcar (lambda (x) (cons (string-to-char (cdr x)) (car x)))
tibetan-precomposition-rule-alist))
;;;###autoload
(defun tibetan-decompose-region (from to)
"Decompose Tibetan text in the region FROM and TO.
This is different from `decompose-region' because precomposed
Tibetan characters are decomposed into normal Tibetan character
sequences."
(interactive "r")
(save-restriction
(narrow-to-region from to)
(decompose-region from to)
(goto-char from)
(while (not (eobp))
(let* ((char (following-char))
(slot (assq char tibetan-decompose-precomposition-alist)))
(if slot
(progn
(delete-char 1)
(insert (cdr slot)))
(forward-char 1))))))
;;;###autoload
(defun tibetan-decompose-string (str)
"Decompose Tibetan string STR.
This is different from `decompose-string' because precomposed
Tibetan characters are decomposed into normal Tibetan character
sequences."
(let ((new "")
(len (length str))
(idx 0)
char slot)
(while (< idx len)
(setq char (aref str idx)
slot (assq (aref str idx) tibetan-decompose-precomposition-alist)
new (concat new (if slot (cdr slot) (char-to-string char)))
idx (1+ idx)))
new))
;;;
;;; This variable is used to avoid repeated decomposition.
;;;
(setq-default tibetan-decomposed nil)
;;;###autoload
(defun tibetan-decompose-buffer ()
"Decomposes Tibetan characters in the buffer into their components.
See also the documentation of the function `tibetan-decompose-region'."
(interactive)
(make-local-variable 'tibetan-decomposed)
(cond ((not tibetan-decomposed)
(tibetan-decompose-region (point-min) (point-max))
(setq tibetan-decomposed t))))
;;;###autoload
(defun tibetan-compose-buffer ()
"Composes Tibetan character components in the buffer.
See also docstring of the function `tibetan-compose-region'."
(interactive)
(make-local-variable 'tibetan-decomposed)
(tibetan-compose-region (point-min) (point-max))
(setq tibetan-decomposed nil))
;;;###autoload
(defun tibetan-post-read-conversion (len)
(save-excursion
(save-restriction
(let ((buffer-modified-p (buffer-modified-p)))
(narrow-to-region (point) (+ (point) len))
(tibetan-compose-region (point-min) (point-max))
(set-buffer-modified-p buffer-modified-p)
(make-local-variable 'tibetan-decomposed)
(setq tibetan-decomposed nil)
(- (point-max) (point-min))))))
;;;###autoload
(defun tibetan-pre-write-conversion (from to)
(setq tibetan-decomposed-temp tibetan-decomposed)
(let ((old-buf (current-buffer)))
(set-buffer (generate-new-buffer " *temp*"))
(if (stringp from)
(insert from)
(insert-buffer-substring old-buf from to))
(if (not tibetan-decomposed-temp)
(tibetan-decompose-region (point-min) (point-max)))
;; Should return nil as annotations.
nil))
;;;
;;; Unicode-related definitions.
;;;
(defvar tibetan-canonicalize-for-unicode-alist
'(("<EFBFBD><EFBFBD><EFBFBD><EFBFBD>" . "") ;; remove vowel a
("" . "ཱི") ;; decompose vowels whose use is ``discouraged'' in Unicode 3.0
("" . "ཱུ")
("" . "ྲྀ")
("" . "ྲཱྀ")
("" . "ླྀ")
("" . "ླཱྀ")
("" . "ཱྀ"))
"Rules for canonicalizing Tibetan vowels for Unicode.")
(defvar tibetan-canonicalize-for-unicode-regexp
"[<5B><><EFBFBD><EFBFBD>ཱཱིུྲྀཷླྀཹཱྀ]"
"Regexp for Tibetan vowels to be canonicalized in Unicode.")
(defun tibetan-canonicalize-for-unicode-region (from to)
(save-restriction
(narrow-to-region from to)
(goto-char from)
(while (re-search-forward tibetan-canonicalize-for-unicode-regexp nil t)
(let (
;;(from (match-beginning 0))
;;(to (match-end 0))
(canonical-form
(cdr (assoc (match-string 0)
tibetan-canonicalize-for-unicode-alist))))
;;(goto-char from)
;;(delete-region from to)
;;(insert canonical-form)
(replace-match canonical-form)
))))
(defvar tibetan-strict-unicode t
"Flag to control Tibetan canonicalizing for Unicode.
If non-nil, the vowel a is removed and composite vowels are decomposed
before writing buffer in Unicode. See also
`tibetan-canonicalize-for-unicode-regexp' and
`tibetan-canonicalize-for-unicode-alist'.")
;;;###autoload
(defun tibetan-pre-write-canonicalize-for-unicode (from to)
(let ((old-buf (current-buffer))
(strict-unicode tibetan-strict-unicode))
(set-buffer (generate-new-buffer " *temp*"))
(if (stringp from)
(insert from)
(insert-buffer-substring old-buf from to))
(if strict-unicode
(tibetan-canonicalize-for-unicode-region (point-min) (point-max)))
;; Should return nil as annotations.
nil))
(provide 'tibet-util)
;;; tibet-util.el ends here