Hi,
I'm trying to "dynamically" create classes which I would then like to
instantiate. The behavior I would like to achieve is that:
guile> (define c (make-a-class 'some-name))
guile> (define obj (make c))
guile> obj
#<<my-class> some-name deadbeef>
To that purpose, I have a metaclass named `<my-class>' and a procedure
`make-a-class' that simply returns instances of `<my-class>'. Since
`compute-cpl' is customized for instances of `<my-class>', I can make
sure that instances of `<my-class>' have a proper CPL that includes
`<top>'. Here's the code:
(use-modules (oop goops))
(read-set! keywords 'prefix)
(define-class <my-class> (<class>)
(the-slot :init-value #t))
(define-method (compute-cpl (c <my-class>))
(format (current-error-port) "CPL (~a)~%" c)
(list c <top>))
(define-method (make-instance (c <my-class>))
(format (current-error-port) "make-instance (~a)~%" c)
(next-method))
(define (make-a-class name)
(let ((c (make <my-class>)))
(slot-set! c 'name name)
c))
The issue is that when instantiating an instance of `<my-class>' (read
that twice ;-)), I'm getting the following error:
;; Create a class (instance of `<my-class>').
guile> (define c (make-a-class 'paf))
CPL (#<<my-class> ??? 301f8930>)
guile> c
#<<my-class> paf 301f8930>
;; Instantiate it.
guile> (make c)
make-instance (#<<my-class> paf 301f8930>)
<unnamed port>: In expression (let* (#) (format # "make-instance (~a)~%" ...)
...):
<unnamed port>: No applicable method for #<<generic> initialize (10)> in call
(initialize #<struct 301f8930:301f7320> ())
ABORT: (goops-error)
This is quite unexpected since I would expect, at least, the
`initialize' class for instances of `<top>' to be applicable. The other
surprising thing is that the instance to be initialized is still seen as
#<struct ...> instead of #<paf ...> or some such.
Any idea?
Thanks,
Ludovic.
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