[no subject]

CC: (BUG LISPM) at MIT-MC
    ALAN@MIT-AI 11/07/79 23:45:33 Re: parallel and sequential binding.
    To: MOON at MIT-MC
        MOON@MIT-MC 11/07/79 21:35:53 Re: parallel and sequential binding.
            Date: Wed ,7 Nov 79 06:08:00 EDT
            From: RMS at MIT-AI (Richard M. Stallman)
            
            How about changing PROG to bind its variables in parallel
            like DO and LET, but introducing PROG* which would bind them
            sequentially as PROG does now.  PROG* would be like LET*....
        I don't see how this could be worth the incompatibility.  Better would
        be to leave PROG alone and not use it new programs.
    Well I hate to be the one to say this, but there are still places where
    PROG (or some PROGlike thing without the repeatness of DO) is what
    is wanted.  A parallel PROG would only be incompatable for LispMachine
    code, since the MacLisp PROG doesn't need to make the distinction.
    Now this is not to say that we should make this proposed change,
    but perhaps it can't be brushed off that easily. (Have you ever used
    PROG in such a way that it would make a difference?)
Yes, I forgot that in Maclisp you can't give initial values.  So the
incompatibility is not so gross as I thought.   There are certainly lots
of macros which use PROG in such a way that they can tell whether it
is sequential or parallel.  However, since this would only be in code
written for the Lisp machine making the change is at least
contemplatable.

It still sounds like an unimportant change that would get in the
way of a lot of people's work, but if RMS or someone wants to do
all the work involved in making the change, I won't object.  However,
it -is- important that &AUX binding be left sequential.