lisp/case-table.el

   1 ;;; case-table.el --- code to extend the character set and support case tables
   2
   3 ;; Copyright (C) 1988, 1994 Free Software Foundation, Inc.
   4
   5 ;; Author: Howard Gayle
   6 ;; Maintainer: FSF
   7 ;; Keywords: i18n
   8
   9 ;; This file is part of GNU Emacs.
  10
  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 2, or (at your option)
  14 ;; any later version.
  15
  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.
  20
  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., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; Written by:
  29 ;; TN/ETX/TX/UMG Howard Gayle        UUCP : seismo!enea!erix!howard
  30 ;; Telefonaktiebolaget L M Ericsson  Phone: +46 8 719 55 65
  31 ;; Ericsson Telecom                  Telex: 14910 ERIC S
  32 ;; S-126 25 Stockholm                FAX  : +46 8 719 64 82
  33 ;; Sweden
  34
  35 ;;; Code:
  36
  37 (defvar set-case-syntax-offset 0)
  38
  39 (defvar set-case-syntax-set-multibyte nil)
  40
  41 (defun describe-buffer-case-table ()
  42   "Describe the case table of the current buffer."
  43   (interactive)
  44   (let ((description (make-char-table 'case-table)))
  45     (map-char-table
  46      (function (lambda (key value)
  47                  (aset
  48                   description key
  49                   (cond ((not (natnump value))
  50                          "case-invariant")
  51                         ((/= key (downcase key))
  52                          (concat "uppercase, matches "
  53                                  (char-to-string (downcase key))))
  54                         ((/= key (upcase key))
  55                          (concat "lowercase, matches "
  56                                  (char-to-string (upcase key))))
  57                         (t "case-invariant")))))
  58      (current-case-table))
  59     (save-excursion
  60      (with-output-to-temp-buffer "*Help*"
  61        (set-buffer standard-output)
  62        (describe-vector description)
  63        (help-mode)))))
  64
  65 (defun copy-case-table (case-table)
  66   (let ((copy (copy-sequence case-table)))
  67     ;; Clear out the extra slots so that they will be
  68     ;; recomputed from the main (downcase) table.
  69     (set-char-table-extra-slot copy 0 nil)
  70     (set-char-table-extra-slot copy 1 nil)
  71     (set-char-table-extra-slot copy 2 nil)
  72     copy))
  73
  74 (defsubst set-case-syntax-1 (char)
  75   "Offset CHAR by `set-case-syntax-offset' if CHAR is a non-ASCII 8-bit char."
  76   (if (and (>= char 128) (< char 256))
  77       (+ char set-case-syntax-offset)
  78     char))
  79
  80 (defun set-case-syntax-delims (l r table)
  81   "Make characters L and R a matching pair of non-case-converting delimiters.
  82 This sets the entries for L and R in TABLE, which is a string
  83 that will be used as the downcase part of a case table.
  84 It also modifies `standard-syntax-table' to
  85 indicate left and right delimiters."
  86   (setq l (set-case-syntax-1 l))
  87   (setq r (set-case-syntax-1 r))
  88   (aset table l l)
  89   (aset table r r)
  90   ;; Clear out the extra slots so that they will be
  91   ;; recomputed from the main (downcase) table.
  92   (set-char-table-extra-slot table 0 nil)
  93   (set-char-table-extra-slot table 1 nil)
  94   (set-char-table-extra-slot table 2 nil)
  95   (modify-syntax-entry l (concat "(" (char-to-string r) "  ")
  96                        (standard-syntax-table))
  97   (modify-syntax-entry r (concat ")" (char-to-string l) "  ")
  98                        (standard-syntax-table)))
  99
 100 (defun set-case-syntax-pair (uc lc table)
 101   "Make characters UC and LC a pair of inter-case-converting letters.
 102 This sets the entries for characters UC and LC in TABLE, which is a string
 103 that will be used as the downcase part of a case table.
 104 It also modifies `standard-syntax-table' to give them the syntax of
 105 word constituents."
 106   (unless (= (charset-bytes (char-charset uc))
 107              (charset-bytes (char-charset lc)))
 108     (error "Can't casify chars with different `charset-bytes' values"))
 109   (setq uc (set-case-syntax-1 uc))
 110   (setq lc (set-case-syntax-1 lc))
 111   (aset table uc lc)
 112   (aset table lc lc)
 113   (set-char-table-extra-slot table 0 nil)
 114   (set-char-table-extra-slot table 1 nil)
 115   (set-char-table-extra-slot table 2 nil)
 116   (modify-syntax-entry lc "w   " (standard-syntax-table))
 117   (modify-syntax-entry uc "w   " (standard-syntax-table)))
 118
 119 (defun set-case-syntax (c syntax table)
 120   "Make character C case-invariant with syntax SYNTAX.
 121 This sets the entry for character C in TABLE, which is a string
 122 that will be used as the downcase part of a case table.
 123 It also modifies `standard-syntax-table'.
 124 SYNTAX should be \" \", \"w\", \".\" or \"_\"."
 125   (setq c (set-case-syntax-1 c))
 126   (aset table c c)
 127   (set-char-table-extra-slot table 0 nil)
 128   (set-char-table-extra-slot table 1 nil)
 129   (set-char-table-extra-slot table 2 nil)
 130   (modify-syntax-entry c syntax (standard-syntax-table)))
 131
 132 (provide 'case-table)
 133
 134 ;;; case-table.el ends here