Re: [Help-smalltalk] Adding data to OOPs

[Paolo Bonzini]

Unfortunately, this is out of discussion.  You are wasting up to 33% 
more space for every object (33% for FloatEs and short strings, 25% for 
FloatDs, Points and Associations, ...).

> And it should be alright from here, with mst_Object and gst_object_header
> being sized somewhat correctly for GST memory management. As you can see it
> is a Smalltalk <-> Objective-C bridge I developed, which I am moving almost
> directly into GST for this project. Actually, it would be ince if objClass
> was the first, and could transparently act as OOP class and ObjC Class...

If you can manage to do so this is fine.

If you really need the pointer to come first, allocate Objective-C 
objects with malloc (in FixedSpace, so they do not move across GC's and 
the GC does not need to walk them), reserve 4 more bytes than necessary, 
put your objc_class* there, return to Smalltalk the pointer to objSize, 
and add a new mapping to the C call-out mechanism that adjusts back the 
pointer to point to the objc_class*.

The idea of bridging GST and Objective-C has came up a few times in the 
past and is indeed a good one, but it needs to be as little invasive as 
possible.  For example, the Java bridge in Smalltalk 2.1e requires *no* 
change to the VM that was not desirable on its one (the only change 
required was the implementation of variable classes for values other 
than unsigned 8- and 32-bit integers).

Paolo