Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ukma!xanth!mcnc!godot!thorn
From: thorn@godot.radonc.unc.edu (Jesse Thorn)
Newsgroups: comp.lang.lisp
Subject: Re: ENVOS COMMON LISP
Message-ID: <1019@godot.radonc.unc.edu>
Date: 21 Mar 89 19:12:19 GMT
References: <6540@arisa.Xerox.COM>
Distribution: na
Organization: Radiation Oncology NCMH/UNC, Chapel Hill, NC
Lines: 70


In article <654@arisia.Xerox.COM> Ronald A. Fischer writes about
considering Lisp development environments when comparing/benchmarking different
Lisp systems.


>Consider how much shorter your development time
>might be with a better set of development tools or application
>toolkit.

While I have never worked with ENVOS I did spend 4 years doing product
development in InterLisp on Xerox D machines - the environment sounds
identical. I can not overemphasize how valuable the development
environment  was to the development effort. These tools included the structure
editor DEDIT, the object inspector, the D window system, the debugger
package, SPY, MASTERSCOPE, CLISP, DWIM, LOOPS, etc, etc. 

The environment really helped to reduce development time and it allowed people
to do rapid prototyping e.g. make massive exploratory code changes quickly.

( Refer to "Power Tools for Programmers" (?) by Beau Sheils
onetime president of Xerox AIS (?). This magazine article describes
the benefits of a rich development environment i.e. the D machine. 
It has appeared in _Datamation_ and several books on programming environments
and user interfaces. )

I have since done product development in VAXLisp under VMS and Ultrix,
PSL under Ultrix, and Golden Common Lisp under MS-DOS. 
They produce very fast code but when I last used them they had 
just about NIL in the way of development tools - vi/edt/emacs and what 
was called a "debugger". 

When moving to these Lisps it seemed that the first thing developers
who were familiar with D machines or Symbolics boxes did
was to write some basic tools that were missing in
these environments (extensions to the debugger, xref utilities, 
performance timing utilities, a file package manager, etc). Not what you 
wanted to do when faced with deadlines.

Project development slowed considerably due to the effort put into
developing and maintaining the support tools as well as the relative
lack of a supportive development environment.

The environment IS the Lisp at least for development. In the best of
worlds you would do development on your D machine equivalent and then
port the finished code to your "fast" production machine.

>I've also not touched on the basic problem that many highly optimized
>Lisps will now produce "unsafe" code, i.e. it will crash your Lisp
>image or worse operating system if simple errors occur.  This has...

This makes debugging extremely difficult. I have worked
with "fast" Lisps that have had this problem. At one time a popular MS-DOS
Lisp had a compiler bug that would produce code that 
trashed memory and initiated a perpetual GC. It took weeks
to find the cause, and weeks to convince the vendor that there was a
problem and get a patch. This all happened a few months before the product
was to be shipped!

A nostalgia for my old 1108 and that wonderful software from Xerox
Parc has prompted this message. I now code in C on Unix systems - surely 
the Goths have invaded the temple...

P.S Anyone from Bachman or Apex out there? Drop me a line.

Jesse "It could be worse - It could be DOS" Thorn
North Carolina Memorial Hospital
Chapel Hill, NC
UUCP:  ...!mcnc!godot!thorn,
INTERNET:  thorn@godot.radonc.unc.edu