[comp.lang.fortran] *THE SPECIAL CASE*

ags@h.cc.purdue.edu (Dave Seaman) (09/21/88)

In article <3821@lanl.gov> jlg@lanl.gov (Jim Giles) writes:
>You are the one who keeps
>introducing into the discussion things which weren't relevant to the
>original issue.  

On the contrary, you are the one who keeps changing the subject and 
talking about the general case.  To see clearly what is happening, 
take a look at the subject line above.  I have changed it.  I am now 
talking ONLY about the special case.  I expect you to do likewise, 
unless you use a different subject line.

Do we have agreement on the ground rules?  Good.

Now, I will ask my question one last time:  why is my code example 
illegal?

No, the answer is not "because side effects are not allowed in 
Fortran."  That is not answering the question.  That is changing the 
subject.  Get the picture?

Let me help.  The answer is, "because section _____ of the standard 
says _________________".  You fill in the blanks.  No paraphrasing, 
please.  I insist on an exact quote.

How about it?

-----------------------------------------------------------------------
Fair warning:  I intend to post again, with THE GENERAL CASE as my 
subject.  Since you were the one who introduced that discussion and 
kept returning to it every time I tried to discuss MY subject, I 
thought you were entitled to know.  Of course, you don't have to 
respond, if you find it too difficult to stick to logic and can no longer 
accuse me of changing the subject.
-- 
Dave Seaman	  					
ags@j.cc.purdue.edu

jlg@lanl.gov (Jim Giles) (09/22/88)

From article <3994@h.cc.purdue.edu>, by ags@h.cc.purdue.edu (Dave Seaman):
> Now, I will ask my question one last time:  why is my code example 
> illegal?
> 

The example you gave appears to be legal.  The optimization I gave for
your example also appears to be legal.  It appears that the semantics
of Fortran may be ambiguous in this case.  I claim that any case in which
the semantics of a programming language are ambiguous is a case which
the programmer should regard as illegal.  I regard multiple side effects
in C expressions as illegal - because the semantics of such things are
ambiguous

YES!!! I ADMIT IT!!!! You have found a case that I thought was illegal
and now it appears to be _merely_ ambiguous in meaning.  Now, are you still
going to maintain that it should be used by programmers (as you have been
doing).  Or, do you think it should have the same status as the 'i=f(i++)'
type of operation in C?  That is, it should be illegal but the committee
hasn't said so yet.

J. Giles
Los Alamos