From: Richard A. O'Keefe
Subject: Re: lisp environments summary
Date: 
Message-ID: <448@cresswell.quintus.UUCP>
    Peter Schachte and I work at the same place, and some-times on the same
project.  I have a Xerox Lisp Machine in my office.  Love it.  HATE the
file manager.  If you are used to developing code with a text editor like
EMACS and then slurping it in, coming to grips with the file manager can
be very painful and very counter-intuitive.

    I think it is worth pointing out that there are things that the
in-core/structure-editor approach cannot handle, and that is #+ stuff
where the code to be skipped on a particular system includes constructs
which that system cannot represent.  For example,
    (setq eps
        #+(feature large-exponents-available) 1.0e-999
        #-(feature large-exponents-available) 1.0e-38
    )
This actually is an issue if you want to write numerical functions in Lisp,
where the tolerance to be used depends on the precision available.  (There
are better ways to do this, the point is that this is a reasonable thing
to do and that it involves numbers which some Lisps can't represent.)

    One problem with the old Interlisp way of doing things was that they
hadn't really taken the file-as-data-base idea sufficiently seriously,
and tried to represent the things saved in a file manager file as TEXT.
I have lost count of the number of times I have had a variable held in
a file manager file where the code has failed because an array or record
was written out as {TYPENAME}ADDRESS which then read back as a LITATOM.
Doing a proper job of the file-as-data-base idea means having a data base
which is not affected by current syntax tables or packages and where
the utility that writes stuff out checks that nothing is written which
cannot be read back.

    Now that we have the Lyric release, Peter Schachte and I can compromise.
I can write files in Common Lisp syntax (on a SUN using an EMACS lookalike,
with the D-machine talking TCP/IP to the SUN, or on the D-machine with
TEDIT), test them on the D-machine, and then hand them over to him.  He
can convert them to the file manager, and we're both happy.

    Even so, I reckon that the D-machines with Xerox Common Lisp are a nice
environment.