Re: [Chicken-users] tinyclos and variable argument functions

[felix winkelmann]

> 
> I also think there might be a problem with define-macro... With the above 
> patch to tinyclos,
> the following code gives somewhat strange results:
> 
> #;2> (define-method (foo (a <top>) b) (print "two " a " " b))
> #;3> (define-method (foo (a <top>)) (print "one " a))
> #;4> (foo 3 2)
> Error: bad argument count - received 3 but expected 2
> #;4> (foo 3)
> one 3
> "one "
> #;5> (define-method (foo (a <top>) (b <top>)) (print "two other " a " " b))
> #;6> (foo 3 2)
> two other 3 2
> "two other "
> 
> What is going on here is that when expanding the first define-method, 
> define-method is
> passing the list of specializers to (add-global-method) as '(<top>).  This is 
> because
> of lines 482 in chicken-highlevel-macros.scm:
>     (if (or (not (pair? args))
>             (and (not (pair? (car args)))
>                  (not (scan (cdr args))) ) )
> Since define-method stops generating the list of specializers when it finds 
> no more
> pairs left in the list of arguments, b's type (which is <top>) is never 
> getting added
> to the list. It makes for a wierd case where wrapping b inside a (b <top>) 
> works
> whereas it doesn't if b is just left open.
> 
> Thus, during add-method, since the list of specializers for the first method 
> is equal
> to the list for the second, the second define-method is replacing the first.
> 

But is this so weird? A non-specialized argument ("b" in the first
define-method) must be an instance of something in the end...


cheers,
felix