[racket] Defining a typed language

Sam Tobin-Hochstadt writes:

 > You can't turn this feature off -- it's a fundamental part of the
 > macro system. There are a few strategies that you can employ here:
 > 
 > 1. If your language is written with #lang, then you can insert, at
 > `read` time, an extra form, perhaps just `(begin)`. Then all your
 > modules will have at least two forms.
 > 2. You can also, in the #lang case, `read` directly to
 > `#%module-begin` wrapped around everything, which will mean that your
 > #%module-begin gets control right away.

Both of these look doable. Thanks for the suggestion!

Konrad.