[Help-smalltalk] ObjectSpaces

[Gwenaël Casaccio]

Hi,

I would like to present a simple concept "ObjectSpaces":
grouping all objects inside  an objectspace, each time
that we send a message to another OS each of the
OSes will intercept the message.

The first usage for me was for process isolation and having
a way to know to what process objects belong. But we could
use them as a security layer between each isolated
processes (in the sence of unix not threads), we can use
them as a recursive definition of process (a process inside a
proces inside a ... ;-) I've made a prototype where I use them
as sandbox and actor model by using the fact that a Space intercept
the messages. We could use them as a reflective
 boxes (a la metaxa or metajava). I guess we could use them as kind
of transactional worlds (i.e. Worlds: Controlling the Scope of Side Effects
http://lambda-the-ultimate.org/node/3040). Another usage is
to scope of the reflection to a space I've made a prototype of it
too you couldn't get all the external instances (that belong
to another space) of a class. And I guess there are much more
possibilities ;-) I've in mind a module system, ...

I've made several implementation of the OSes  the most advanced
had multiple object tables and threaded interpreter but there were
too much bugs inside it ^^ But that was funny to do. The most recent
puts an hidden instance variable inside each objects (which is fine for
a prototype implementation)

Cheers,
Gwen