[self-interest] Re: oz patch

[David Ungar]

Neat! I'll have to try it out.
And if you want exceptions, it should be easy to implement them:
just a push-down stack in the process objects (one per process) containing
blocks.
You should be able to hide it behind a "tryIfFail:" method.
Jecel, I'm sure you know we already have the unwinding methods for blocks,
you would probably want to use them to pop the exception handler stack on NLRs.

- Dave


At 10:26 PM -0200 11/11/99, Jecel Assumpcao Jr wrote:
>Mario Wolczko wrote:
>>  All the stuff in  the CACM article is in 4.0, methinks, including
>>  turning off stepping for morphs whose step method is broken.
>
>True. I finally drummed up some courage and took a look at this
>part of the code. I can't say I followed it fully as it is one of
>the most twisted pieces of code I ever saw (the most was the Unix
>kernel). Wouldn't all this be much simpler if Self had proper
>exception handling? You know, like
>
>   ...  [ ... m drawOn: .... ] tryIfFail: [ ... 'world is broken!'...]
>
>>  The proxy idea is neat.
>
>I tried something more in the style of what is there already:
>
>    http://www.lsi.usp.br/~jecel/release/patches/ozPatch.self
>
>If you file this in, it will break the UI on the spot, so you
>have to do this first:
>
>    desktop worlds first _AddSlots: ( | current | )
>
>That is, supposing you have only one world open. This is obviously
>*very* quick and dirty, but if you break a morph it is removed
>from the world and a notifier comes up - clicking on its button
>gets you an outliner for the morph. The notifier is actually a bit
>redundant as you also get a debugger showing what went wrong
>and you could easily fetch the outliner from there.
>
>Anyway, the whole point is to be able to continue in the same
>world after the most common morphic boo boos. And that is nicer
>than getting dumped in a new windows (specially if other people
>are in the same world with you), isn't it?
>
>-- Jecel
>
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     David Ungar
     Sun Microsystems Laboratories
     (650) 336-2618