1 ;; Calculator for GNU Emacs, part II [calc-undo.el]
2 ;; Copyright (C) 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
3 ;; Written by Dave Gillespie, daveg@synaptics.com.
5 ;; This file is part of GNU Emacs.
7 ;; GNU Emacs is distributed in the hope that it will be useful,
8 ;; but WITHOUT ANY WARRANTY. No author or distributor
9 ;; accepts responsibility to anyone for the consequences of using it
10 ;; or for whether it serves any particular purpose or works at all,
11 ;; unless he says so in writing. Refer to the GNU Emacs General Public
12 ;; License for full details.
14 ;; Everyone is granted permission to copy, modify and redistribute
15 ;; GNU Emacs, but only under the conditions described in the
16 ;; GNU Emacs General Public License. A copy of this license is
17 ;; supposed to have been given to you along with GNU Emacs so you
18 ;; can know your rights and responsibilities. It should be in a
19 ;; file named COPYING. Among other things, the copyright notice
20 ;; and this notice must be preserved on all copies.
24 ;; This file is autoloaded from calc-ext.el.
29 (defun calc-Need-calc-undo () nil)
36 (and calc-executing-macro
37 (error "Use C-x e, not X, to run a keyboard macro that uses Undo."))
43 (if (null (nthcdr (1- n) calc-undo-list))
44 (error "No further undo information available"))
47 (nthcdr n calc-undo-list)
48 (let ((saved-stack-top calc-stack-top))
49 (let ((calc-stack-top 0))
50 (calc-handle-undos calc-undo-list n))
51 (setq calc-stack-top saved-stack-top))))
55 (defun calc-handle-undos (cl n)
58 (let ((old-redo calc-redo-list))
59 (setq calc-undo-list nil)
60 (calc-handle-undo (car cl))
61 (setq calc-redo-list (append calc-undo-list old-redo)))
62 (calc-handle-undos (cdr cl) (1- n))))
65 (defun calc-handle-undo (list)
67 (let ((action (car list)))
69 ((eq (car action) 'push)
70 (calc-pop-stack 1 (nth 1 action) t))
71 ((eq (car action) 'pop)
72 (calc-push-list (nth 2 action) (nth 1 action)))
73 ((eq (car action) 'set)
74 (calc-record-undo (list 'set (nth 1 action)
75 (symbol-value (nth 1 action))))
76 (set (nth 1 action) (nth 2 action)))
77 ((eq (car action) 'store)
78 (let ((v (intern (nth 1 action))))
79 (calc-record-undo (list 'store (nth 1 action)
80 (and (boundp v) (symbol-value v))))
81 (if (y-or-n-p (format "Un-store variable %s? " (nth 1 action)))
84 (set v (nth 2 action))
86 (calc-refresh-evaltos v)))))
87 ((eq (car action) 'eval)
88 (calc-record-undo (append (list 'eval (nth 2 action) (nth 1 action))
89 (cdr (cdr (cdr action)))))
90 (apply (nth 1 action) (cdr (cdr (cdr action))))))
91 (calc-handle-undo (cdr list))))
96 (and calc-executing-macro
97 (error "Use C-x e, not X, to run a keyboard macro that uses Redo."))
101 (if (null (nthcdr (1- n) calc-redo-list))
102 (error "Unable to redo"))
105 (nthcdr n calc-redo-list)
106 (let ((saved-stack-top calc-stack-top))
107 (let ((calc-stack-top 0))
108 (calc-handle-redos calc-redo-list n))
109 (setq calc-stack-top saved-stack-top))))
113 (defun calc-handle-redos (cl n)
116 (let ((old-undo calc-undo-list))
117 (setq calc-undo-list nil)
118 (calc-handle-undo (car cl))
119 (setq calc-undo-list (append calc-undo-list old-undo)))
120 (calc-handle-redos (cdr cl) (1- n))))
123 (defun calc-last-args (n)
125 (and calc-executing-macro
126 (error "Use C-x e, not X, to run a keyboard macro that uses last-args."))
128 (let ((urec (calc-find-last-x calc-undo-list n)))
130 (calc-handle-last-x urec)
131 (error "Not enough undo information available"))))
134 (defun calc-handle-last-x (list)
136 (let ((action (car list)))
137 (if (eq (car action) 'pop)
138 (calc-pop-push-record-list 0 "larg"
139 (delq 'top-of-stack (nth 2 action))))
140 (calc-handle-last-x (cdr list))))
143 (defun calc-find-last-x (ul n)
145 (if (calc-undo-does-pushes (car ul))
148 (calc-find-last-x (cdr ul) (1- n)))
149 (calc-find-last-x (cdr ul) n)))
152 (defun calc-undo-does-pushes (list)
154 (or (eq (car (car list)) 'pop)
155 (calc-undo-does-pushes (cdr list))))