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 ;;; Code:
  29
  30 (defvar set-case-syntax-set-multibyte nil)
  31
  32 (defun describe-buffer-case-table ()
  33   "Describe the case table of the current buffer."
  34   (interactive)
  35   (let ((description (make-char-table 'case-table)))
  36     (map-char-table
  37      (function (lambda (key value)
  38                  (aset
  39                   description key
  40                   (cond ((not (natnump value))
  41                          "case-invariant")
  42                         ((/= key (downcase key))
  43                          (concat "uppercase, matches "
  44                                  (char-to-string (downcase key))))
  45                         ((/= key (upcase key))
  46                          (concat "lowercase, matches "
  47                                  (char-to-string (upcase key))))
  48                         (t "case-invariant")))))
  49      (current-case-table))
  50     (save-excursion
  51      (with-output-to-temp-buffer "*Help*"
  52        (set-buffer standard-output)
  53        (describe-vector description)
  54        (help-mode)))))
  55
  56 (defun copy-case-table (case-table)
  57   (let ((copy (copy-sequence case-table)))
  58     ;; Clear out the extra slots so that they will be
  59     ;; recomputed from the main (downcase) table.
  60     (set-char-table-extra-slot copy 0 nil)
  61     (set-char-table-extra-slot copy 1 nil)
  62     (set-char-table-extra-slot copy 2 nil)
  63     copy))
  64
  65 (defun set-case-syntax-delims (l r table)
  66   "Make characters L and R a matching pair of non-case-converting delimiters.
  67 This sets the entries for L and R in TABLE, which is a string
  68 that will be used as the downcase part of a case table.
  69 It also modifies `standard-syntax-table' to
  70 indicate left and right delimiters."
  71   (aset table l l)
  72   (aset table r r)
  73   ;; Clear out the extra slots so that they will be
  74   ;; recomputed from the main (downcase) table.
  75   (set-char-table-extra-slot table 0 nil)
  76   (set-char-table-extra-slot table 1 nil)
  77   (set-char-table-extra-slot table 2 nil)
  78   (modify-syntax-entry l (concat "(" (char-to-string r) "  ")
  79                        (standard-syntax-table))
  80   (modify-syntax-entry r (concat ")" (char-to-string l) "  ")
  81                        (standard-syntax-table)))
  82
  83 (defun set-case-syntax-pair (uc lc table)
  84   "Make characters UC and LC a pair of inter-case-converting letters.
  85 This sets the entries for characters UC and LC in TABLE, which is a string
  86 that will be used as the downcase part of a case table.
  87 It also modifies `standard-syntax-table' to give them the syntax of
  88 word constituents."
  89   (let ((lu (length (string-as-unibyte (string uc))))
  90         (ll (length (string-as-unibyte (string lc)))))
  91     (unless (= lu ll)
  92       (error "Can't casify chars with different `charset-bytes' values")))
  93   (aset table uc lc)
  94   (aset table lc lc)
  95   (set-char-table-extra-slot table 0 nil)
  96   (set-char-table-extra-slot table 1 nil)
  97   (set-char-table-extra-slot table 2 nil)
  98   (modify-syntax-entry lc "w   " (standard-syntax-table))
  99   (modify-syntax-entry uc "w   " (standard-syntax-table)))
 100
 101 (defun set-case-syntax (c syntax table)
 102   "Make character C case-invariant with syntax SYNTAX.
 103 This sets the entry for character C in TABLE, which is a string
 104 that will be used as the downcase part of a case table.
 105 It also modifies `standard-syntax-table'.
 106 SYNTAX should be \" \", \"w\", \".\" or \"_\"."
 107   (aset table c c)
 108   (set-char-table-extra-slot table 0 nil)
 109   (set-char-table-extra-slot table 1 nil)
 110   (set-char-table-extra-slot table 2 nil)
 111   (modify-syntax-entry c syntax (standard-syntax-table)))
 112
 113 (provide 'case-table)
 114
 115 ;;; case-table.el ends here