[racket] Tutorial: writing a language (brainf*ck) in Racket

> The dilemma was to choose a language that was simple, and looked
> nothing like Racket.  The choice was clear: it had to be brainf*ck.
> Here's the tutorial:
> 
>     http://planet.racket-lang.org/package-source/dyoo/bf.plt/1/2/planet-docs/manual/index.html
> 
> Comments and suggestions would be greatly appreciated.

Nice!

For the tape: thought about using a zipper data structure, rather than
a vector?

Means you can grow the size of the tape rather naturally, and don't have
to deal with negative indices.