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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: comp.lang.c
Subject: Re: C and Floating Point
Message-ID: <7918@utzoo.UUCP>
Date: Thu, 16-Apr-87 11:40:31 EST
Article-I.D.: utzoo.7918
Posted: Thu Apr 16 11:40:31 1987
Date-Received: Thu, 16-Apr-87 11:40:31 EST
References: <15958@sun.uucp>
Organization: U of Toronto Zoology
Lines: 28
Keywords: C Fortran Floating Point Parenthases

>   The standards committee has as one of it's obligations to define rules
> that will allow writing code which will work on the largest number of 
> compilers as possible with little or no change.  Allowing the compiler 
> to, at it's option, totaly ignore the EXPLICIT wishes of the programmer 
> is one of the easiest ways I can think of to produce a "standard" which 
> unnecessarily frustrates programmers, will actualy _Cause_ portability
> problems, and is, in fact not a functional "Standard" at all.

If you re-read paragraph 2 on page 185 of K&R, you will find that C has
always been this way.  C programmers who expect anything different do not
understand the language they are programming in, which is a guaranteed
way to become frustrated and cause portability problems.  X3J11 has always
given high priority to preserving the functioning of existing legitimate
C programs; programs which depend on order of evaluation do not come under
this heading, since C has always allowed rearrangement.

Some languages do interpret parentheses as an expression of the programmer's
wish to force order of evaluation.  Some do not.  C does not.  The problem
is not that the compiler is ignoring the programmer's wishes, but that the
programmer does not understand how to express his wishes in C (as opposed
to Fortran).

I assure you that when you understand the language, it is not difficult to
write code that will work on the largest number of computers possible with
little or no change.
-- 
"We must choose: the stars or	Henry Spencer @ U of Toronto Zoology
the dust.  Which shall it be?"	{allegra,ihnp4,decvax,pyramid}!utzoo!henry