Bijan Parsia wrote:

	Just a point. It's not clear that Strings *should* be resizable. In
	Python, they're an immutable type (like Tuples, unlike lists). In Prolog
	and Erlang they are mutable---and indeed, they are just lists of
	characters.
	
While strings *are* just (singly linked) lists of characters in Prolog and
Erlang, they are *not* mutable.  In fact *no* lists are mutable in Prolog
or Erlang.  Come to think of it, Prolog and Erlang don't have any mutable
data structures, period.  (Programs they can change, but not data structures.)