Re: Issue: LOAD-TIME-EVAL (Version 8)

[David N Gray <Gray@DSG.csc.ti.com>]

> > guess that the most likely route to a solution will involve defining
> > some sort of "tree walk" through the source code, defining the identity
> > of a form as the path taken through the tree to reach that form.  I'm
> > guessing that the intuition that the proposal intended to capture is the
> > same thing that this tree walk does.
> 
> Yes, that is pretty much what I had in mind, but I agree it is not
> formally stated.  Perhaps a more formal statement would be that you do
> a code walk to expand all macros, then do a COPY-TREE on the resulting
> code, then all the LOAD-TIME-VALUE expressions you end up with would have
> the right uniqueness properties.

In other words, the interpreter would be required to do a pre-pass over the
code.  In discussions in other contexts, it seemed that the consensus was
that we did not want to require a pre-pass implementation approach or to rule
out a displacing macros approach.  I don't think we want to reverse that
position just to satisfy the fine print in this one feature.

> > Alternatively, you might abandon the intuition and think about the 
> > consequences of just using EQ of the LOAD-TIME-VALUE expression.  Would
> > it be so bad?
> 
> That's pretty much the alternative I mentioned above, I guess.

This looks like the only viable answer to me.