Re: how to introduce reference objects into ruby

2. It's also possible to construct things that are pointers to variables
   instead of to objects, if you make them a pair of a holding object
   together with the name of the variable in it. For example, every
local
   context has a Binding object that is associated to it (but is created
   only on-demand, as there is a faster internal form for it). It could
   look like:

I have no experience with Binding objects, but the overhead seems pretty
huge if you want to do this for a lot of element (I want to have this
for each matrix element, not per row, see my previous mail regarding
sparse matrices). Is it feasable to keep all these Bindings for all the
elements of my matrix?

If you were to implement references in the core of ruby, how would you 
deal with fixnums?

The problem is not that a Fixnum stores its content in the VALUE struct
itself. I see such a Reference object as an empty box that can contain a
single Ruby VALUE and that has a modified assignment operator:
ref=Reference.new(12)
ref=15
This last assignment will make in normal Ruby ref equal to the Fixnum
VALUE 15, while in the modified Ruby, an assignment to a Reference
object makes sure ref stays the same object, but the content of ref gets
updated and will contain 15. So, I don't see any problems with Fixnums,
it is my feeling that only the assignment operator should act
differently for reference objects than for other Ruby objects.

Greetings,
Geert.