[plt-scheme] How do I do this in true functional style?

Joe Marshall writes:
 > Additionally, you may wish to use the printed representation of the
 > desired 3-dimensional array of booleans.  This will avoid the entire
 > process of initialization.

What if the array is very sparse, e.g. a 100x100x100 cube with 20
points?

 > I use Emacs macros, SED, AWK, LEX, or whatever to strip out noise
 > like commas and put in parenthesis, quotations, etc.

Dumb question, but why not use Scheme to do this?

 > If you find yourself mutating structure, you should consider the
 > drawbacks.

On the other hand, the alternative is functional array update, which
is inefficient unless you have a really good compiler (which will just
turn it into mutation anyway).

--dougo at place.org