Function: decipher-set-map

decipher-set-map is a byte-compiled function defined in decipher.el.gz.

Signature

(decipher-set-map CIPHER-CHAR PLAIN-CHAR &optional NO-UNDO)

Source Code

;; Defined in /usr/src/emacs/lisp/play/decipher.el.gz
;;--------------------------------------------------------------------
;; Mapping ciphertext and plaintext:
;;--------------------------------------------------------------------

(defun decipher-set-map (cipher-char plain-char &optional no-undo)
  ;; Associate a ciphertext letter with a plaintext letter
  ;; CIPHER-CHAR must be an uppercase or lowercase letter
  ;; PLAIN-CHAR must be a lowercase letter (or a space)
  ;; NO-UNDO if non-nil means do not record undo information
  ;; Any existing associations for CIPHER-CHAR or PLAIN-CHAR will be erased.
  (setq cipher-char (upcase cipher-char))
  (or (and (>= cipher-char ?A) (<= cipher-char ?Z))
      (error "Bad character"))          ;Cipher char must be uppercase letter
  (or no-undo
      (decipher-add-undo (decipher-get-undo cipher-char plain-char)))
  (let ((cipher-string (char-to-string cipher-char))
        (plain-string  (char-to-string plain-char))
        case-fold-search                ;Case is significant
        mapping bound)
    (save-excursion
      (goto-char (point-min))
      (if (setq mapping (rassoc cipher-char decipher-alphabet))
          (progn
            (setcdr mapping ?\s)
            (search-forward-regexp (concat "^([a-z]*"
                                           (char-to-string (car mapping))))
            (decipher-insert ?\s)
            (beginning-of-line)))
      (if (setq mapping (assoc plain-char decipher-alphabet))
          (progn
            (if (/= ?\s (cdr mapping))
                (decipher-set-map (cdr mapping) ?\s t))
            (setcdr mapping cipher-char)
            (search-forward-regexp (concat "^([a-z]*" plain-string))
            (decipher-insert cipher-char)
            (beginning-of-line)))
      (search-forward-regexp (concat "^([a-z]+   [A-Z]*" cipher-string))
      (decipher-insert plain-char)
      (setq case-fold-search t          ;Case is not significant
            cipher-string    (downcase cipher-string))
      (let ((font-lock-fontify-region-function #'ignore))
        ;; insert-and-inherit will pick the right face automatically
        (while (search-forward-regexp "^:" nil t)
          (setq bound (point-at-eol))
          (while (search-forward cipher-string bound 'end)
            (decipher-insert plain-char)))))))