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From: bobd@zaphod.UUCP (Bob Dalgleish)
Newsgroups: net.ai,net.lang.lisp
Subject: Re: Re: Multi-language systems
Message-ID: <212@zaphod.UUCP>
Date: Wed, 20-Mar-85 19:21:01 EST
Article-I.D.: zaphod.212
Posted: Wed Mar 20 19:21:01 1985
Date-Received: Sat, 23-Mar-85 01:01:29 EST
References: <242@bu-cs.UUCP>, <316@cmu-cs-k.ARPA> <253@bu-cs.UUCP>, <494@harvard.ARPA> <259@bu-cs.UUCP>
Organization: Develcon Electronics, Saskatoon, SK
Lines: 44
Xref: watmath net.ai:2656 net.lang.lisp:413

> ...
> Just as in natural language, computer languages cluster into families.
> There is nothing hard about mixing FORTRAN & COBOL modules into a big
> system (or FORTAN & PL/I).  I've done plenty of that sort of stuff.
> It's when you move across families where things break down, and
> especially where you try mixing an inherently interpreted language like
> LISP or SNOBOL with an inherently compiled one like FORTRAN that things
> get dangerous.
> 
> 						Bill Henneman

My understanding is that Honeywell Multics allows/supports/encourages
multiple language systems by defining data structures in parameters in a
language-independent way.  Thus, my neighbourhood Multics fanatic says
it is easy and natural to mix LISP and PL/I (admittedly not ANSI
standard).  Similarly, DEC provides a common calling convention (which
does not go nearly far enough - parameters are more interesting than
calls).

What I tell my young people (:-) is to choose "horses for courses" - use
the best language for the task at hand.  Medium to large projects
unfortunately present a number of courses, but only one language can be
used.  We have attempted to disguise our single horse by using
preprocessors and application generators when possible to provide more
natural notation - database management and language parsing are prime
candidates for this.

My dream horse is one that allows me to specify what kind of course I
am going to run for the next little while - the language acquires new
or different capabilities to allow me to express my programs
naturally.  I know what happens to such bastard horses (er, languages)
- they are called PL/I, LISP 2.0, Ada, etc. and they earn the undying
contempt of the base language purists and the fear of those who cannot
deal with having more than one way to look at a problem.  The
alternative is to provide an extensible language - such languages are
often only trivially extensible (i.e., you still have to know the
underlying language), or are so powerful as to overwhelm all but the
most brave.
-- 
[The opinions expressed here are only loosely based on the facts]

Bob Dalgleish		...!alberta!sask!zaphod!bobd
			      ihnp4!
(My company has disclaimed any knowledge of me and whatever I might say)