Re: [Chicken-users] coops

[schugk]

> The version you install is 1.1

Then a new version does not solve my problem. Here is some code:

(define-generic (show s))

(define-method (show (s <number>))
  (number->string s))

(define-method (show (s <symbol>))
  (symbol->string s))

(define-method (show (s <pair>))
  (string-append "(" (show (car s)) "," (show (cdr s)) ")"))

(define-method (show (s <list>))
    (apply string-append (map show s)))

I expected that (show '(1 2 3 4)) is evaluated to "123". But the  
specialized method for <list> is only called if the value of s is  
<null>. Instead the method for <pair> is called and is evaluated to  
"(1,(2,(3,(4,(5,)))))". My problem is that <pair> is always preferred  
because <pair> is a subclass of <list>. If i change some lines in  
coops-primitive-objects.scm so that <list> is a subclass of <pair>  
everything works fine.

Is there a reason why <pair> is a subclass of <list>?

Thanks,
Sandro

coops-primitive-objects.scm changed to

48: (defprim <pair> pair? <sequence>)
49: (defprim <list> list? <pair>)
50: (defprim <null> null? <immediate> <list>)