[racket] typed racket and interfaces

On 2014-05-02 21:36:07 -0400, Alexander D. Knauth wrote:
>    And it gave me this error:
>    . Type Checker: not a valid type: #:implements in: #:implements

This example works for me. I forgot to ask though: are you trying to run
this on Racket v6.0?

Typed Racket prior to the current pre-release (and the upcoming v6.0.1)
mostly does not support classes. If you don't have a pre-release build
already, you can get one here (at one of the linked snapshot sites):

  http://pre.racket-lang.org/

Cheers,
Asumu