Changes by: Aleksey Nogin (nogin at cs.caltech.edu)
Date: 2000-05-17 16:01:20 -0700 (Wed, 17 May 2000)
In Ocaml, string is a mutable data structure. In MetaPRL, we use strings everywhere (variable
names, opnames, etc) as if they were immutable. We need to
a) Make sure that nobody can cheat the system by starting to mute strings.
b) Let the compiler and GC know that we are not going to mute strings (which should allow
them to be more efficient).