Problems with Win32/WinCE VMs - backing out of changes

Dan Ingalls Dan.Ingalls at disney.com
Wed Sep 1 17:11:03 UTC 1999


>I tried protected projects and they didn't really work for me...

I'm not surprised.  The code that is there right now is only a first pass.
If we were to give it a warrantee, it would be "Has worked at least once".

>With a well implemented copy-on-write scheme, this doesn't have to  
>have any impact on 'image-style' development.  It can also be the  
>starting point for a more complete implementation (Hans Martin's  
>Collage).

I agree that a good copy-on-write scheme would be a really nice solution.  By lightening the save/restore overhead, it would allow a very simple checkpoint/rollback mechanism.

There are lots of reasons for ALSO having an integrated event/history/undo management system.  Ideally this could be applied at any level, including, eg, desktop publishing and presentation graphics as well as scripting and Squeak development itself.

As far as Squeak Central is concerned, we haven't planned to do any work on segmented images in the next 6 months (although image segments, yes).  We do, however, hope to make some progress on higher level event recording, undo, redo and the like, mainly with an eye to supporting end-user activity, but it should be applicable to Squeak development as well.

	- Dan





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