From mboxrd@z Thu Jan  1 00:00:00 1970
From: nicolas.pouillard@gmail.com (Nicolas Pouillard)
Date: Mon, 27 Apr 2009 21:47:00 +0200
Subject: [sup-talk] redo ideas
In-Reply-To: <200904271244.n3RCi1VO027803@smtp6.server.rpi.edu>
References: <200904271244.n3RCi1VO027803@smtp6.server.rpi.edu>
Message-ID: <1240861270-sup-8603@ausone.local>

Excerpts from Mike S's message of Mon Apr 27 14:43:46 +0200 2009:
> I'm graduating in a few weeks, so I'll have some free time I can dedicate 
> to sup again.
> 
> Recently redo functionality was suggested, I believe this was meant to be 
> a solution for something, but I have been thinking about it for a while.
> I'd like to register Ctrl-R to keep with the vim bindings.

Just some thoughts about this... I was more thinking about the repeat feature
of Vi/Vim (the '.' command) than the redo one.

Two other ways of doing the undo/redo:

1/ Save the actions using a data type that we can inverse.
   Example in Ruby syntax
   a = Action.add_labels(:foo, :bar)
   a.apply # actually do the job
   a.invert # equals to Action.remove_labels(:foo, :bar)

2/ Save the state (has to be defined) at each action.
   This solution would be limited to actions where the state is manageable.

Best regards,

-- 
Nicolas Pouillard