From c3a05d7447ad00d1306b7fb66db1335a9562e065 Mon Sep 17 00:00:00 2001
From: Joseph Ferano first-even does above.
(Option T) is how absence is spelled: a lookup miss, an empty
collection, the end of a stream. match works on an Option, a
defdata and an enum, whose arms name cases; on a bool, whose arms
-are true and false; and on a number, a string or a
+are true and false and need no _; and on a number, a string or a
dyn, whose arms are literals — (match n 0 "zero" -1 "none" _ "some"),
or over a dyn also keywords such as :north
— each compared with =, with a _ arm required for the rest.