[erlang-questions] Matching Empty maps

[Richard A. O'Keefe]

The frames proposal did something similar.
I tried the experiment of requiring |_ to say
"other things can be present", with the absence
of this meaning exact key agreement.

But writing sample programs I found that I was
CONSTANTLY leaving the |_ out when it should have
been there, and of course it missed half of the
*point* of using records/frames/maps, namely that
you can add a new field without breaking existing
code.