ri...@happyleptic.org writes:
> (define (hook-helper %s) (lambda () #\t))
>
> where %s is the long list of parameters (foo bar baz...) that's inserted by
> the C program.
> And :
>
> (define (hook . args) (local-eval (cons print-user-fields user-fields)
> (procedure-environment (apply hook-helper args))))
Using local-eval and procedure-environment like this won't work in Guile
1.9/2.0, I believe.
But you could get a similar effect - which I think will still work in
1.9/2.0 - by creating a module, defining values in it, and then
evaluating in that module. (In Guile, module == top level environment.)
(Note that the bindings in a module are conceptually similar to an alist,
so this is actually not so different from what Thien-Thi suggested.)
To create a module, in Scheme:
(define-module (xxx))
Then your C code would access that using
SCM module = scm_c_resolve_module ("xxx");
and define each value in it using
scm_c_module_define (module, name, value);
and finally evaluate in that module using
scm_c_eval_string_in_module (expression, module);
It would also seem (at least to me) a bit less magical to define the
user-fields as a procedure, e.g.:
(define (calc-user-fields)
(list foo
bar
(+ baz foo)
(if (> foo bar) 1 2)))
and then the "expression" above would be "(calc-user-fields)".
All completely untested, of course! :-)
Regards,
Neil
