[Chicken-users] Dynamic Callbacks without SWIG

[Francisco Rafael Leon]

Hello all,

I spent some time struggling to get callbacks working with SWIG, but
then decided that there must be an easier way than dealing with SWIG
pointers and C_save and C_callback.  I came up with this (in pure scheme!):

-----------------
;compile this with csc

(use lolevel)

(define-external (dynfcn (double x)) double 
                 ((global-ref (string->symbol "myfunc")) x))

(load "rest-of-program.scm")

------------------

You can then re-define "myfunc" as many times as you wish inside of the
interpreted code "rest-of-program.scm".  External C code can call
"dynfcn", and it will be dynamically bound inside chicken on each call.

Amazingly, this explicit dynamic binding with global-ref seems to work
fine.

Sincerely,

F. Rafael Leon