[Chicken-users] better printer for coops instances?

[Marco Maggi]

This script:

(require-library (coops)
                 (coops-primitive-objects))
(module (coops-demo)
    ()
  (import (scheme)
          (coops)
          (coops-primitive-objects))
  (define-method (doit (x <integer>) (y <integer>) (z <integer>))
    (+ x y z))
  (doit #\z 2 3)
  #| end of module |# )

prints an error beginning with:

Error: (doit) no method defined for given argument classes: (#<coops-instance> 
#<coops-instance> #<coops-instance>)

I would really enjoy seeing something similar to:

   #<coops-instance class=<char> value=#\z>
   #<coops-instance class=<fixnum> value=2>
   #<coops-instance class=<fixnum> value=3>

instead of "#<coops-instance>".  Is something like this possible?

TIA
-- 
Marco Maggi