Archive for November, 2013

RPN Calc Part 3 – Undo

Posted Nov 19 2013 by with 0 Comments

One of the reasons given in the GoF book for the use of the command pattern is to support undo. By recording the commands executed by a user, and giving the commands the ability to reverse themselves, a user interface can be designed to allow users to undo mistakes they make. For this post, I’ll talk about how this is done in the undoable version of rpncalc.

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