Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!purdue!i.cc.purdue.edu!h.cc.purdue.edu!ags
From: ags@h.cc.purdue.edu (Dave Seaman)
Newsgroups: comp.lang.fortran
Subject: Re: *THE GENERAL CASE* (was: function side effects)
Message-ID: <4012@h.cc.purdue.edu>
Date: 26 Sep 88 03:29:09 GMT
References: <4007@h.cc.purdue.edu> <4100@lanl.gov>
Reply-To: ags@h.cc.purdue.edu.UUCP (Dave Seaman)
Organization: Purdue University
Lines: 41

In article <4100@lanl.gov> jlg@lanl.gov (Jim Giles) writes:
>Both of them do since the specific case we were discussing was the replacement
>of i=i+1 with i+=1.  You were the one who implied that:
>      A(F(I))=A(F(I))+1
>was allowed to have F modify I on the call. (In response to what I said
>that this function call wasn't allowed side effects, you quoted the
>standard which allowed functions to change their args.  They can't
>in this case.  This was the case under discussion - as explicitly
>placed into the subject line.)

I did not intend to respond to this discussion again, but you have once
again misrepresented what I said, and I must therefore once again set the
record straight.

I have never said or implied that the function F in the statement you give
could modify its argument I.  My point was always that it could modify an
unrelated variable in COMMON, which could subsequently affect other parts
of the program.  The point of my example about dummy arguments was simply
that you had made an incorrect statement.  It turns out that you did not
mean what you wrote, but I certainly was not aware of that at the time.  I
happen to know that I am not the only person who, on reading your posting,
thought you actually meant that NO functions were allowed to have side
effects.

Claiming that the statement "Fortran functions are not allowed to have
side effects" is irrelevant to the subject line is like claiming that the
First Amendment to the U.S. Constitution is irrelevant to any argument
over whether American citizens between the ages of 37 and 43 are permitted
to discuss duck hunting in a public saloon after 4:30 on Thursday
afternoons.  The fact is that your statement, had it been true, would have
settled the argument in your favor.  That fact alone makes the statement
relevant.

I think we should simply agree that there was a misunderstanding between
us on what you meant, which has since been cleared up, and therefore does
not merit further discussion.

Please refrain from misrepresenting what I said.  The argument is over.
-- 
Dave Seaman	  					
ags@j.cc.purdue.edu