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From: gjc@mitech.COM
Newsgroups: comp.lang.scheme
Subject: Return value of SET!/SETQ/=, and order of evaluation
Message-ID: <9104011524.AA09177@schizo>
Date: 29 Mar 91 17:23:49 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Reply-To: gjc@mitech.com
Organization: The Internet
Lines: 49

Actually, throw in the fact that in Scheme the empty list
and logical false are DIFFERENT.

As a LISP programmer for over 10 years I find it much more comfortable
to program in C than in the latest Scheme standards.

HEY GUYS: I think you have really blown it, BIG TIME.

In C, I use the return value of assignments all the time.
It is a very common programming practice. Also, I use the fact
that the NULL pointer is logical false. And also, I use the
order of evaluation implied by "&&" and "||" quite a bit.
And it isn't just me, it is hundreds of thousands of C programmers.

The way that Scheme is defined now, WELL, it just forces the
programs to be much more verbose, with lots of extra LAMBDA/LET
statements, and local variables, and even extra assignments.

And I think it is just "peachy keen" and even "neeto" that
that is exactly the kind of extra crap that Scheme Compiler Righters
(writers?) think they there compilers and so good at.

Fact: I think my compilers are good at removing extra local
      variables and crap
Therefore: I think I will design the language to force users to
           introduce a lot of extra crap so that my compiler
           gets to show how good it is at removing it.


It sure starts to smell like PASCAL to me.

No longer do we have a LISP which is EXPRESSION oriented in the
way that BLISS and quite a bit of C was. Instead we get something
more of the flavor of the old languages with the
statement/expression classification.

There are some things in Scheme which are clearly "STATEMENTS"
that is, forms which make no sense to use in a "EXPRESSION" (value)
context. There there are things which are expressions.

OK. Is a procedure call important? If so, then why is it not
possible to define a procedure which has no defined return value?

That is, why is it not possible to extend the language (via procedure
definitions) in the class of STATEMENTS (e.g. built in SET!-CAR
vs my own defined SET!-FROB)? Why only in the class of EXPRESSIONS?


-gjc