[racket] Use of map and eval to evaluate symbol in namespace

Matthew Flatt wrote at 08/04/2014 02:40 AM:
> While he didn't say so explicitly, I don't think that Neil is worried
> about the implementation of `eval` within Racket. After all, `eval` is
> at the heart of the implementation, and any program that you give to
> Racket is going through `eval` whether or not the program calls the
> `eval` function.

Correct.  I breathe oxygen constantly, without thinking about it, but 
I'd never use a fuel-air explosive to mow my lawn.

Neil V.