Re: [PATCH] Implement `the-environment' and `local-eval' in evaluator

[Mark H Weaver <mhw@netris.org>]

I wrote:
> Having thought more about this, I'm fully convinced that 'module-a
> should be the answer.

On second thought, I don't think my argument was very solid.  My nephew
demanded my attention while I was working on that email, and so I rushed
it out when I should have put it aside and pondered some more.

So, in cases where (the-environment) is found within a macro template,
I guess I'm still undecided about whether the captured expander
environment should be at the point of (the-environment), or whether it
should be at the point of the initial macro use that led to that
expansion.

However, I'm fairly sure that those are the only two sane options, and I
feel quite certain that the module used by `local-eval' should be taken
from the captured expander environment, whatever that may be.

Do people agree with that those are the two sane options?
Any thoughts on which one is more useful?

I guess we should try to come up with examples of useful macros that use
(the-environment), and hope that these examples point to a clear winner.

For that matter, in the unlikely case that both options seem genuinely
useful, it wouldn't be hard to implement both, since they would both
translate to the same `tree-il' type.  The only difference would be in
the expander, since it puts the <expander-environment> into the tree-il
node, and that piece of code is only a few lines.

Thoughts?

     Best,
      Mark