[plt-scheme] immutable strings vs. uninterned symbols

Eli Barzilay writes:
 > It's the concept of a different type for different
 > uses.  Otherwise you would feel just as well in a world that uses
 > numbers/strings/church-encodings/goedel-numbers for everything.

Right, but there's more to a type than just what procedures
accept/produce it.  In some ways that's the least interesting part,
especially if I'm going to make an abstract type on top of it, in
which case none of those procedures should be used.  But different
types in Scheme also have different performance characteristics,
different behavior in equivalence predicates, and different forms for
parsing and printing.  (Are there other differences?  Garbage
collection maybe?)

--dougorleans at gmail.com