Re: Improving the LISP working environment by taking a lesson from...

[Richard M. Stallman <RMS at MIT-AI>]

    Date: 10 Nov 1980 10:41 PST
    From: Deutsch at PARC-MAXC
    In-reply-to: SHRAGE's message of 10 Nov 1980 (Monday) 0512-EDT

    1- In Interlisp, the Masterscope facility lets you easily find out
    what all your functions, variables, etc. names are.

EMACS makes it easy to find out what Lisp functions you have in a
file, and where they are called from, even among several files.

    2- The SYSOUT facility in Interlisp makes it very cheap (in time)
    to create checkpoints which you can resume from later.  Many
    Interlisp users prefer the APL "workspace" style, keeping a SYSOUT
    around to work in for days or weeks.

Maclisp also allows an environment to be saved, just as easily, but
there is no application for it in our normal way of working.  We keep
our programs in text files, not in Lisp environments.  When programs
are kept in files, it is usually not useful to save a checkpoint.

    3- It's not simply a matter of "cover functions", different Lisp
    systems have chosen to develop themselves in quite different
    directions.  For example, Interlisp has put tremendous emphasis on
    managing the programming process through history retention,
    building up a data base of your code, etc., while MACLisp has
    placed more emphasis on efficient compilation and certain kinds of
    system simplicity.

This is unfair and misleading.  The absense of tools for programming
in Maclisp is because we do the programming in EMACS.  The tools are
in EMACS, not in Lisp.