Standard total ordering

[Jeff Dalton <jeff%aiai.edinburgh.ac.uk@NSS.Cs.Ucl.AC.UK>]

In Prolog, there is a standard total ordering for terms (i.e., all
data).  This is often quite useful.  For example, it is faster to
search an ordered list for membership than to search an unordered
one.

Note that the order is essentially arbitrary: what matters is that any
terms may be consistently compared.  (OK, what really matters is all
the properties of a total order.)

To what extent is it possible to do something like this for Lisp?

In a Lisp where objects never move (or never change order relative to
each other), the object's address could be used.  This assumes we are
ordering objects as distinguished by EQ.  Is there some point in
ordering for EQUAL objects instead?

Jeff Dalton,                      JANET: J.Dalton@uk.ac.ed             
AI Applications Institute,        ARPA:  J.Dalton%uk.ac.ed@nss.cs.ucl.ac.uk
Edinburgh University.             UUCP:  ...!ukc!ed.ac.uk!J.Dalton