[racket] a little macro exercise

Eli Barzilay wrote at 10/08/2010 10:57 PM:
> Here's a much shorter version that doesn't require goto emulation, 

Nice.  On principle, I was going to trouble to avoid redundant tests, as 
well as give the compiler a single optimization-friendly "case" form, 
followed by tail calls.  In practice, I guess any runtime performance 
difference would likely be in the noise.

-- 
http://www.neilvandyke.org/