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From: slack@wxlvax.UUCP (Tom Slack)
Newsgroups: net.ai
Subject: Re: Multi-language systems
Message-ID: <420@wxlvax.UUCP>
Date: Wed, 20-Mar-85 12:31:34 EST
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Posted: Wed Mar 20 12:31:34 1985
Date-Received: Fri, 22-Mar-85 02:24:43 EST
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> However, I my reference to Whorf was possibly to elliptic.  Whorf was an
> American linguist who advanced the hypothesis that the language you
> speak greatly influences the way you think about the world around you.
> As I said, whether or not his hypothesis is valid for natural languages,
> it is certainly true for computer languages.  Implicit in the fact that
> I am writing a program in COBOL is the decision that the data flow is
> important, and the control flow is trivial.  Similar judgements go into
> any choice of language for any program I write.  I try to match the tool
> to the job.  Each language has its own strengths and weaknesses, but the
> price paid for the strength of any given language is that it imposes a
> problem-solving style on the programmer.

I agree with this fundamentally, however the correct approach for the 
progammer worth his salt is to say that all successfull programming
languages (read problem-solving styles) have some merit.
A good 3rd generation system such as C or PASCAL can implement these
styles albeit with some difficulty provided the programmer has them
firmly established in his mind.

> 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.

The Good Programmer should know fairly well languages from several families.

> A system which is dangerously multi-lingual will, in my view, perforce
> be difficult to maintain because it is opaque for the two reasons cited
> above: some of the code will be obscure because it is faking an
> environment for the sibling, and the rest will lack unity of style.
> Speaking from experience, I can say that no one person is going to be
> able to understand the whole system.  I've been programming since 1955,
> and I've never met a programmer equally proficient in all languages.

Here is where I really disagree.
I have not known a really good programmer who was not very proficient
in at least two families of Languages.  Usually one of those was 
PL/1 C or PASCAL.
The others were from RPG ALGOL APL and LISP to
many macro assemblers FORTH or even COBOL.
It may be that they have a preferred language 
(Mine was APL till I learned LISP),
but they are quite comfortable in the other.
Nothing says that people cannot think two ways (or more).

> Some languages match their thought processes, and some don't.  The
> amount of worthwhile communication between a FORTRAN programmer and a
> LISP programmer is non-measurable, because their fundemental ideas about
> what programming is are irreconcilable.
> 
> 						Bill Henneman

I would change this to read:
The amount of worthwhile communication between a programmer who only knows
FORTRAN and one who only knows LISP is non-measurable, ...

Tom Slack