[racket] How to use typed/racket within Emacs and scheme top level ???

  I tried (require typed/scheme) in the scheme evaluation
buffer and then basic expressions evaluated with C-c-e
(such as #(44 #\c), say) evaluate fine with nice type
annotations.

But struct: definitions always generate an error. Specifically,
just the test case (struct: Foo ([a : Fixnum])) generates the
following error:

 > stdin::35: dtsi*: expected struct name at: foo
in: (dtsi* () foo ((a : Fixnum)) #:maker foo)

I then tried to wrap code in a (module foo typed/scheme ....),
but evaluations produced no output via 'display' and so forth.

Hopefully I'm missing some basic configuration and or code
structuring and interactive evaluation tactics.

Any and all advice greatly appreciated! Thanks much in
advance!

- Scott