David Kastrup <d...@gnu.org> writes:
> In the light of local-eval evaluating a _form_ rather than a _body_
> (stupid of me to forget), and seeing the weird semantics of begin, I
> agree that an implicit (let () ...) wrapper for a single form does not
> really appear to add significant gains. It would be marginally
> convenient and marginally confusing.
>
> So one might as well forget about it.
Except possibly for symmetry: how does plain eval handle it?
guile> (let ((x 2)) (eval '(begin (define x 4) x) (current-module)))
4
guile> x
4
guile>
Right through to the top. And we couldn't do that in local-eval. But
it also has no qualms just because previously evaluated forms would have
used a previous definition of x. But that's because of top-level. Eval
is always top-level, and define acts like set! there.
What if the-environment had been taken at top-level (basically just
carrying the information of (current-module))? Should local-eval then
behave accordingly? If so, could we not just fold eval and local-eval
into one function? And one could then define
(define current-module
(let ((top-level (the-environment)))
(lambda () (eval '(the-environment) top-level))))
if the-environment just returns the current module when at top level?
Basically, I can accept your reasoning. This is just putting out a bit
of brainstorming.
--
David Kastrup
