[racket] thank you for typed racket

>  -- I wrote a compiler
>  -- I benefited from TR because ...
>  -- And I need X Y and Z from R because pedestrian languages
>        such as ML and Haskell don't support it

I should add that I'm using other parts of Racket, like the web-server
package, to let me write automated tests on the prototype.  A problem
that I need to deal with is: once I've generated some JavaScript, how
do I test it automatically with a real web browser's evaluator?  I
want all my tests to be expressed in Racket, and I don't want to
depend on any external packages, such as Selenium.  So I'm using
web-server to feed JavaScript and get back evaluated results back into
Racket.  See:

https://github.com/dyoo/js-sicp-5-5/blob/master/browser-evaluate.rkt

and:

https://github.com/dyoo/js-sicp-5-5/blob/master/test-browser-evaluate.rkt

for a preliminary sketch.