[racket] redex + #lang = awesome

David Van Horn wrote:

> Then I thought, PCF's binding structure is a lot like Racket's: wouldn't
> it be nice to get syntax coloring, syntax arrows, renaming, etc.  That
> was about another 30 lines of code.

Can you say a few words about how you achieved this? Thanks to Matthew's 
article and RacketCon tutorial, I now know how creating languages works, 
but he didn't cover this last bit. I could start poring over the code, 
but I suspect a minute or two of your time will save me a lot more. 
Thanks. --PR