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Date:	Thu, 7 Aug 2003 15:37:34 PDT7
From:	Tom Novelli <tcn@mtdata.com >
Reply-To:	scoug-programming@scoug.com
To:	< "scoug-programming@scoug.com" > scoug-programming@scoug.com >
Subject:	SCOUG-Programming: Re: Warpstock 2003 Presentation

Content Type: text/plain

On Thu, 7 Aug 2003, Lynn H. Maxson wrote:
> Imperative languages require that the programmer
> "physically" maintain the source in its "logical" order. The
> ordering (writing) and reordering (rewriting) remains a
> programmer responsibility.

As it should be. This is why your typical office worker prefers
spreadsheets over databases and programmers prefer real languages
over GW-BASIC... the ordering is implicit.

> The "a = b = c;", a statement valid in PL/I and not in C,
> represents operator overload. The first "=" is the assignment
> operator;the second, the logical operator. Now C gets cute by
> introducing "==" along with "&&" and "||". PL/I would be
> better off by dropping the "=" for assignment by using the
> APL left arrow ("<-") to make the statement read "a <- b =
> c;", i.e. replace the value of a with '1'b if b = c, otherwise '0'b.
>
> I don't want to confuse the C programmer reading this that in
> PL/I a, b, and c could be arrays (dcl (a, b, c) (20, 20, 20)
> bit(1):) and that "a = b = c;" remains valid. Or that even
> possibly you could reset all three to '0'b: "a, b, c = '0'b;". No
> sense in confusing him with the ability to have multiple
> lefthand variables, i.e. multiple assignments in a single
> statement. Let him enjoy the extra typing of C.

That would be written in C as "a = b = c = 0;" since '=' is just another
binary operator which returns the right-hand value. Agreed, '==' vs. '='
is a royal pain, and I'm used to typing '->' to dereference pointers, and
I'd only have to type '=' to test equality if I used '<-' for assignment.
I'll have to try that in my new compiler.

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