[racket] Generics: implemented methods not inherited?

Is there a way to inherit methods from a parent struct?
If I'm not mistaken, it's not what #:defaults and other keywords are for.

For example, the following fails:

#lang racket
(require racket/generic)
(define-generics g
  (foo g)
  (bar g))

(struct a ()
  #:methods gen:g
  [(define (foo g) '(foo a))
   (define (bar g) '(bar a))])

(struct b a ()
  #:methods gen:g
  [(define (foo g) '(foo b))])

(foo (a)) ; '(foo a)
(foo (b)) ; '(foo b)
(bar (a)) ; '(bar a)
(bar (b)) ; Error: bar: not implemented for #<b>


Laurent


On Fri, Sep 6, 2013 at 4:13 PM, Konrad Hinsen <konrad.hinsen at fastmail.net>wrote:

> Asumu Takikawa writes:
>
>  > You can write the method implementations as plain function definitions
>  > in some module, e.g.,
>  >
>  >   (define (my-dict-ref ...) ...)
>  >   ...
>  >   (provide my-dict-ref ...)
>  >
>  > and then in each structure you can do
>  >
>  >   (struct particular-dict (...)
>  >     #:methods
>  >     [(define dict-ref my-dict-ref)
>  >      ...])
>  >
>  > to share the implementations.
>
> That looks so obvious once you see it... Thanks a lot!
>
> Konrad.
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>   Racket Users list:
>   http://lists.racket-lang.org/users
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