[MUD-Dev] Languages

clawrenc at cup.hp.com clawrenc at cup.hp.com
Wed May 21 10:09:02 New Zealand Standard Time 1997

In <199705200947.LAA05046 at regoc.srce.hr>, on 05/20/97 
   at 08:09 AM, silovic at srce.hr (Miroslav Silovic) said:

>(note that if MUD is hard to debug because of no debug support,
>dynamic typing is not the one to blame. Stack trace is your friend in
>all dynamic languages, starting with LISP - and it's something that
>is far harder to program in a static language, although not at all

As mentioned earlier in a recent article in the Journal of the ACM a
bunch of Sun engineers did some interesting work under MOO for a
back-end debugging world.  Essentially what it meant was that normal
user programming would occur in "Kansas" quite normally and unchanged
from normal MOO programming in any way, but if a world-fatal error
occurred (say a bad change to a root object) a user could login into a
parallel but seperate world ("Oz") running on the same server and from
there interactively debug Kansas (both worlds running in parallel with
Oz able to affect Kansas, but Kansas unable to affect Oz).  This
parallelism continued to the extent of allowing an Oz' to debug an Oz,
or an Oz'' for a buggy Oz'.

It is an interesting solution, and one offers some definitely useful
tools.  I though it especially interesting to view as a side-effect of
moving a single-rooted MOO heirarchy to a dynamically generated
multiply rooted heirarchy (Oz and Kansas).  The concept of using that
parrallelism for back-end under-the-covers access the the world is
just flat out intrigueing.

J C Lawrence                           Internet: claw at null.net
(Contractor)                           Internet: coder at ibm.net
---------------(*)               Internet: clawrenc at cup.hp.com
...Honorary Member Clan McFUD -- Teamer's Avenging Monolith...

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