lisp/case-table.el

   1 ;;; case-table.el --- code to extend the character set and support case tables  -*- lexical-binding: t -*-
   2
   3 ;; Copyright (C) 1988, 1994, 2001-2017 Free Software Foundation, Inc.
   4
   5 ;; Author: Howard Gayle
   6 ;; Maintainer: emacs-devel@gnu.org
   7 ;; Keywords: i18n
   8 ;; Package: emacs
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;; Written by:
  28 ;; TN/ETX/TX/UMG Howard Gayle        UUCP : seismo!enea!erix!howard
  29 ;; Telefonaktiebolaget L M Ericsson  Phone: +46 8 719 55 65
  30 ;; Ericsson Telecom                  Telex: 14910 ERIC S
  31 ;; S-126 25 Stockholm                FAX  : +46 8 719 64 82
  32 ;; Sweden
  33
  34 ;;; Code:
  35
  36 (defun describe-buffer-case-table ()
  37   "Describe the case table of the current buffer."
  38   (interactive)
  39   (let ((description (make-char-table 'case-table)))
  40     (map-char-table
  41      (function (lambda (key value)
  42                  (if (not (natnump value))
  43                      (if (consp key)
  44                          (set-char-table-range description key "case-invariant")
  45                        (aset description key "case-invariant"))
  46                    (let (from to)
  47                      (if (consp key)
  48                          (setq from (car key) to (cdr key))
  49                        (setq from (setq to key)))
  50                      (while (<= from to)
  51                        (aset
  52                         description from
  53                         (cond ((/= from (downcase from))
  54                                (concat "uppercase, matches "
  55                                        (char-to-string (downcase from))))
  56                               ((/= from (upcase from))
  57                                (concat "lowercase, matches "
  58                                        (char-to-string (upcase from))))
  59                               (t "case-invariant")))
  60                        (setq from (1+ from)))))))
  61      (current-case-table))
  62     (save-excursion
  63      (with-output-to-temp-buffer "*Help*"
  64        (set-buffer standard-output)
  65        (describe-vector description)
  66        (help-mode)))))
  67
  68 (defun case-table-get-table (case-table table)
  69   "Return the TABLE of CASE-TABLE.
  70 TABLE can be `down', `up', `eqv' or `canon'."
  71   (let ((slot-nb (cdr (assq table '((up . 0) (canon . 1) (eqv . 2))))))
  72     (or (if (eq table 'down) case-table)
  73         (char-table-extra-slot case-table slot-nb)
  74         ;; Setup all extra slots of CASE-TABLE by temporarily selecting
  75         ;; it as the standard case table.
  76         (let ((old (standard-case-table)))
  77           (unwind-protect
  78               (progn
  79                 (set-standard-case-table case-table)
  80                 (char-table-extra-slot case-table slot-nb))
  81             (or (eq case-table old)
  82                 (set-standard-case-table old)))))))
  83
  84 (defun get-upcase-table (case-table)
  85   "Return the upcase table of CASE-TABLE."
  86   (case-table-get-table case-table 'up))
  87 (make-obsolete 'get-upcase-table 'case-table-get-table "24.4")
  88
  89 (defun copy-case-table (case-table)
  90   (let ((copy (copy-sequence case-table))
  91         (up (char-table-extra-slot case-table 0)))
  92     ;; Clear out the extra slots (except for upcase table) so that
  93     ;; they will be recomputed from the main (downcase) table.
  94     (if up
  95         (set-char-table-extra-slot copy 0 (copy-sequence up)))
  96     (set-char-table-extra-slot copy 1 nil)
  97     (set-char-table-extra-slot copy 2 nil)
  98     copy))
  99
 100 (defun set-case-syntax-delims (l r table)
 101   "Make characters L and R a matching pair of non-case-converting delimiters.
 102 This sets the entries for L and R 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
 105 indicate left and right delimiters."
 106   (aset table l l)
 107   (aset table r r)
 108   (let ((up (case-table-get-table table 'up)))
 109     (aset up l l)
 110     (aset up r r))
 111   ;; Clear out the extra slots so that they will be
 112   ;; recomputed from the main (downcase) table and upcase table.
 113   (set-char-table-extra-slot table 1 nil)
 114   (set-char-table-extra-slot table 2 nil)
 115   (modify-syntax-entry l (concat "(" (char-to-string r) "  ")
 116                        (standard-syntax-table))
 117   (modify-syntax-entry r (concat ")" (char-to-string l) "  ")
 118                        (standard-syntax-table)))
 119
 120 (defun set-case-syntax-pair (uc lc table)
 121   "Make characters UC and LC a pair of inter-case-converting letters.
 122 This sets the entries for characters UC and LC in TABLE, which is a string
 123 that will be used as the downcase part of a case table.
 124 It also modifies `standard-syntax-table' to give them the syntax of
 125 word constituents."
 126   (aset table uc lc)
 127   (aset table lc lc)
 128   (let ((up (case-table-get-table table 'up)))
 129     (aset up uc uc)
 130     (aset up lc uc))
 131   ;; Clear out the extra slots so that they will be
 132   ;; recomputed from the main (downcase) table and upcase table.
 133   (set-char-table-extra-slot table 1 nil)
 134   (set-char-table-extra-slot table 2 nil)
 135   (modify-syntax-entry lc "w   " (standard-syntax-table))
 136   (modify-syntax-entry uc "w   " (standard-syntax-table)))
 137
 138 (defun set-upcase-syntax (uc lc table)
 139   "Make character UC an upcase of character LC.
 140 It also modifies `standard-syntax-table' to give them the syntax of
 141 word constituents."
 142   (aset table lc lc)
 143   (let ((up (case-table-get-table table 'up)))
 144     (aset up uc uc)
 145     (aset up lc uc))
 146   ;; Clear out the extra slots so that they will be
 147   ;; recomputed from the main (downcase) table and upcase table.
 148   (set-char-table-extra-slot table 1 nil)
 149   (set-char-table-extra-slot table 2 nil)
 150   (modify-syntax-entry lc "w   " (standard-syntax-table))
 151   (modify-syntax-entry uc "w   " (standard-syntax-table)))
 152
 153 (defun set-downcase-syntax (uc lc table)
 154   "Make character LC a downcase of character UC.
 155 It also modifies `standard-syntax-table' to give them the syntax of
 156 word constituents."
 157   (aset table uc lc)
 158   (aset table lc lc)
 159   (let ((up (case-table-get-table table 'up)))
 160     (aset up uc uc))
 161   ;; Clear out the extra slots so that they will be
 162   ;; recomputed from the main (downcase) table and upcase table.
 163   (set-char-table-extra-slot table 1 nil)
 164   (set-char-table-extra-slot table 2 nil)
 165   (modify-syntax-entry lc "w   " (standard-syntax-table))
 166   (modify-syntax-entry uc "w   " (standard-syntax-table)))
 167
 168 (defun set-case-syntax (c syntax table)
 169   "Make character C case-invariant with syntax SYNTAX.
 170 This sets the entry for character C in TABLE, which is a string
 171 that will be used as the downcase part of a case table.
 172 It also modifies `standard-syntax-table'.
 173 SYNTAX should be \" \", \"w\", \".\" or \"_\"."
 174   (aset table c c)
 175   (let ((up (case-table-get-table table 'up)))
 176     (aset up c c))
 177   ;; Clear out the extra slots so that they will be
 178   ;; recomputed from the main (downcase) table and upcase table.
 179   (set-char-table-extra-slot table 1 nil)
 180   (set-char-table-extra-slot table 2 nil)
 181   (modify-syntax-entry c syntax (standard-syntax-table)))
 182
 183 (provide 'case-table)
 184
 185 ;;; case-table.el ends here