Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!joyce!sri-unix!quintus!ok
From: ok@quintus.uucp (Richard A. O'Keefe)
Newsgroups: comp.lang.fortran
Subject: Re: Pointers in FORTRAN 8X
Message-ID: <513@quintus.UUCP>
Date: 7 Oct 88 07:01:01 GMT
References: <7306@well.UUCP> <3@microsoft.UUCP>
Sender: news@quintus.UUCP
Reply-To: ok@quintus.UUCP (Richard A. O'Keefe)
Organization: Quintus Computer Systems, Inc.
Lines: 24

In article <3@microsoft.UUCP> bobal@microsoft.UUCP (Bob Allison (uunet!microsoft!bobal)) writes:
>I've decided to try to present the proposal going around X3J3 for pointers 
>(which is in the language WG-5 is demanding, I believe).

Thank you.

>So, if you want
>to copy the contents of one structure pointed to by "P" to another structure
>pointed to by "Q", you write "P=Q"; if you want "P" to point to what "Q"
>points to, you write "P=>Q".

Oh dear oh dear oh dear.  Simula 67 had the same idea (the operators were
:= and :-) but the thing which saved Simula was that for a given P and Q
only one of the operators was legal.  The difference between two statements
with such different effects should _not_ be a single character.  In C,
which I do not for a moment claim is ideal, the distance between the
statements is two characters:  *P = *Q; -vs- P = Q;  and in ADA the
difference is 8 characters:  P.all := Q.all;  -vs-   P := Q;
And then to make the operation look as though it assigns P to Q!

We've had enough discontent expressed in comp.lang.c with the fact
that mistyping P==Q (a comparison) may yield a valid expression P=Q
to indicate that single-character errors are alive and well (and of
course Bliss programmers know this to their cost).  When will we learn?