Re: [Chicken-users] Peculiar TinyCLOS specialization bit

[Andreas Rottmann]

"Joel Reymont" <address@hidden> writes:

> Try running the following code:
>
> (require 'tinyclos)
>
> (define-class <a> () ())
> (define-class <b> (<a>) ())
> (define-method (foo (self <b>) (a <a>)) #f)
> (define b (make <b>))
> (foo b #f)
>
> You will get "Error: call-next-method: no methods left: #<procedure>"
> since method foo is expecting an object as it's second argument and is
> getting #f.
>
> I think it should pass, though. Am I missing something?
>
The only method on the generic function foo is specialized on (<b>
<a>), while you pass (<b> <boolean>), so there are no applicable
methods. Some error is the expected behaviour. If you want it to pass,
do

(define-method (foo (self <b>) (a <top>)) #f)

or

(define-method (foo (self <b>) (a <boolean>)) #f)

instead of or additionally to 

(define-method (foo (self <b>) (a <a>)) #f)

HTH, Rotty
-- 
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