Re: wish list

["Jecel Mattos de Assumpcao Jr." <jecel@lsi.usp.br>]

Sorry if there is line noise - my connection is getting worse
each day...
Tue, 31 Oct 1995 09:08:38 +0800, Randall.Smith@Eng.Sun.COM (Randy Smith) wrote:
> > [ my HotSelf idea ]
> 
>
> Dave and I sat down and added this in about 15 minutes!  Press a
> button and end up with some new self object in your hand.

That's great!! Does this mean I get two more wishes ;-) ?

I assume this happens when the broswer find a line like
<a href=xxx.self>click me </a>, right? How about having 
<app=xxx.self> show the resulting object inside the page?
Better yet - make <img src=xxx.gif app=xxx.self> show the
object in the page, and an image of the object in a dumb
browser.

> > [ I claimed undo needed VM support ]
>
>
> Would like to hear your ideas on this one in particular.  What are you
> thinking?  A redo of the assignment primitive to keep a reference to the
> last N old values ??

That would be a bit better than using something like "rawColor" slots
to save old versions, but would not be too efficient - versions, like
wrappers, tend to spread and contaminate the whole system.

Actually, I am not sure what should be done, but I feel it must be
integrated with the garbage collector and the persistent store
system. The best idea I have seen so far is Paul Wilson's "Deamonic
Memory", but he seems to have gone in other directions now. I can
try to get a reference, if there is interest. Anyway, his system
would let you back up the whole system to any point in the past.
That is not what I want. I want to be able to back up a certain set
of objects to any point in the past (and even have some of them
coexist with their current versions!).

Of course there must be a high-level "hook" to all this so the user
can control this from the user interface, but I don't think a good
solution can be made only at the programming environment level (though
a cumbersome one could - a kind of copy-down in time :-)

This is *the* major missing piece for Merlin. If I can't solve this,
then the system will be too dangerous for normal use (at least
Self 4.0 has snapshots...)

--- Jecel