Namestring&pathstring returning shared structure

[lmi-angel!gjc%mc.ARPA]

Why stop at strings Dave? Another win would be immutable list
structure. Think of it, (as the CLU'ist remarked) you can pass a whole
list to a function without having to worry about the possible RPLACA or RPLACD
operations it may do!

Actually, one could make this into a serious suggestion. Certainly most systems
have so-called pure areas, for example, in the LMI system you get a
write-into-read-only-memory error if you do (setf (aref (get-pname 'foo) 0) #\X),
and perhaps this feature could actually be presented in a system-independant way.

Something along the lines of "if the pure-structure feature is provided then
the primitives should be called PURE-COPY (or PURCOPY) and PURE-P."

-gjc