[erlang-questions] Feedback for my first non-trivial Erlang program

[Richard A. O'Keefe]

On the subject of macros vs functions for constants,
there is a third way.
(There should be a fourth way.  Abstract patterns can
do *so* many nice things...)
For a constant that you don't want to use in a pattern
or guard, you can declare a function and then tell the
compiler to -inline it.

My advice would be:
 - If you want to name something that must appear
   in a pattern or guard, you have no choice but to
   use a macro.  (Until abstract patterns are
   implemented.)
 - Otherwise, always start by using plain functions.
   Get the code working, then benchmark and profile it.
   + If performance of these functions is OK, stop worrying.
   + Try inlining and benchmark+profile again.
 +++ It's generally better to try eliminating a calculation
     than to micro-optimise it.