Re: object-properties

[Maciej Stachowiak <mstachow@alum.mit.edu>]

Ian Bicking wrote:
> 
> Happy Presidents' Day everyone!  I hope we all take a moment to
> meditate on those fine presidents of America's past.
> 
> Hehe... what a silly holiday.  Well, anyway...
> 
> I'm thinking about changing the object system in Tcl->Scheme to
> something based on object-properties.  I believe Maciej(?) was
> saying that object-properties was going to become much slower.
> How much slower is that?  With the version of Guile that I am using
> it seems to work about as fast as normal list access (i.e., it's not a
> big win to make a special object type when I can put all the extra
> information in object-properties).

I think it was procedure-properties we were discussing. object-properties
will probably continue to be implemented as a hash table on the object
to an association list of the properties. You may be able to tweak a bit
more speed out of it by using only one property which is a hash table,
but that may slow things down instead.

I really should look at integrating the auto-resizing hash tables
that were worked on on this list a while back, that should make things
more useful.
 
> If object-properties stays reasonable fast or something like it can
> do the same thing, this would make Scheme/Tcl data integration
> fairly seemless (though almost too seemless -- in particular, in-
> place mutation like string-set! is quite incompatible with Tcl's strict
> call-by-value)...

Can you make that actually keep the values as different types properly
in sync in light of arbitrary Scheme manipulation?

 - Maciej

PS, this Tcl stuff is really cool. When it gets reasonably useful and stable,
I want to try to make a scwm configuration file in Tcl, that should be something
of an acid test of usefulness.