Hi,
Maxime Devos <maximede...@telenet.be> skribis:
> I wondered if some kind of 'lexical use-modules' was possible, with
> sufficient macroology and module reflection, and it looks like it is:
I agree it would be useful.
Just yesterday wrote this (my goal here was to allow dynamic module
loading based on some condition);
--8<---------------cut here---------------start------------->8---
(define-syntax with-modules
(syntax-rules ()
"Dynamically load the given MODULEs at run time, making the chosen
bindings available within the lexical scope of BODY."
((_ ((module #:select (bindings ...)) rest ...) body ...)
(let* ((iface (resolve-interface 'module))
(bindings (module-ref iface 'bindings))
...)
(with-modules (rest ...) body ...)))
((_ () body ...)
(begin body ...))))
--8<---------------cut here---------------end--------------->8---
… which can be used like this:
--8<---------------cut here---------------start------------->8---
(with-modules (((fibers) #:select (spawn-fiber sleep))
((fibers channels)
#:select (make-channel put-message get-message)))
(let ((channel (make-channel)))
(spawn-fiber
…)))
--8<---------------cut here---------------end--------------->8---
Unlike ‘use-modules’, its clearly limited to the lexical scope of its
body.
IWBN to have a similar functionality in Guile proper, and it could
probably be made more efficient.
Ludo’.
