comparison lisp/prim/undo-stack.el @ 2:ac2d302a0011 r19-15b2

Import from CVS: tag r19-15b2
author cvs
date Mon, 13 Aug 2007 08:46:35 +0200
parents 376386a54a3c
children 0293115a14e9
comparison
equal deleted inserted replaced
1:c0c6a60d29db 2:ac2d302a0011
102 ;;; 6, which is less than optimal. 102 ;;; 6, which is less than optimal.
103 ;;; 103 ;;;
104 ;;; Conceptually, we can implement the "undoable stack" using 104 ;;; Conceptually, we can implement the "undoable stack" using
105 ;;; two stacks of a sort called "truncatable stack", which are 105 ;;; two stacks of a sort called "truncatable stack", which are
106 ;;; just simple stacks, but where you can truncate elements 106 ;;; just simple stacks, but where you can truncate elements
107 ;;; of of the bottom of the stack. Then, the undoable stack 107 ;;; off of the bottom of the stack. Then, the undoable stack
108 ;;; 108 ;;;
109 ;;; 1 -> 2 -> 3 -> 4 -> 5 -> 6 109 ;;; 1 -> 2 -> 3 -> 4 -> 5 -> 6
110 ;;; ^^ 110 ;;; ^^
111 ;;; 111 ;;;
112 ;;; is equivalent to two truncatable stacks: 112 ;;; is equivalent to two truncatable stacks: