Zelphir Kaltstahl <firstname.lastname@example.org> writes:
The issue is not with defining via (define ...) inside a (let ...) in Guile. It
is about importing macros at the time, when the body of the (let ...) is already
evaluated, which is at a later phase than macro expansion. By wrapping inside a
(let ...) org has moved the import to a later phase, which causes the macro
(let-values ...) to not be expanded.
AFAIK, Elisp does not have this problem.
As far as I know, (defun ...) and (defvar ...) are merely defining functions and
variables, not macros.
Same for defmacro in Elisp.
My point is, that imports are usually global for sessions. But :var decided for
let-wrapping, moving them to a different place. Just like imports are usually
global, I would expect (define ...)s to be global in the session, unless I put
them inside a narrowed scope like a (let ...) myself. The org generated (let
...) is invisible to the user and thus confusing, at least for GNU Guile.
For other Schemes it probably all depends on how their phases of expansion and
evaluation work. I don't know enough about the Scheme standards, to tell,
whether Guile has the correct behavior here or whether there is a correct
behavior defined in the Scheme standards. Maybe someone more knowledgeable can
chime in to comment on that.
When saying Guile I mean scheme. Remember that I am now looking from a
more general perspective of other ob-* libraries.
My conclusion so far is that it is not safe in ob-scheme to use
let-binding. Other ob-* lisp implementations may be OK (at least,
ob-emacs-lisp is OK).
Now, the main question is whether it is safe to use `define' in all the
scheme implementations. If it is, would you be interested in turning
your personal fix into a patch for ob-scheme?