Re: [Chicken-users] tinyclos - how to copy an object?

[Kon Lovett]

On Sep 19, 2007, at 11:40 PM, Shawn Rutledge wrote:

> Is there a generic way to copy an object already?  (Make another
> instance with the same slots)  Or is it necessary to write such a
> function using introspection?

(define copy-object (make-generic "copy-object"))

(add-method copy-object
  (make-method (list <object>)
    (lambda (call-next-method x . initargs)
      (let ([class (class-of x)])
        (apply make class
                    (let ([inited-slot?
                            (lambda (nam)
                              (let loop ([flag #t] [prplst initargs])
                                (and (pair? prplst)
                                     (or (and flag (equal? nam (car  
prplst)))
                                         (loop (not flag) (cdr  
prplst)) ) ) ) )])
                      (for-each
                        (lambda (s)
                          (let ([nam (car s)])
                            (unless (inited-slot? nam)
                              (set! initargs (cons nam (cons (slot- 
ref x nam) initargs))) ) ) )
                        (class-slots class))
                      initargs ) ) ) ) ) )

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