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From: dik@mcvax.UUCP
Newsgroups: comp.lang.c
Subject: Re: Unary plus (and wysiwyg order or evaluation)
Message-ID: <348@zuring.mcvax.cwi.nl>
Date: Sun, 12-Apr-87 11:57:47 EST
Article-I.D.: zuring.348
Posted: Sun Apr 12 11:57:47 1987
Date-Received: Tue, 14-Apr-87 00:05:23 EST
References: <6772@brl-adm.ARPA> <803@viper.UUCP> <752@rtech.UUCP>
Reply-To: dik@zuring.UUCP (Dik T. Winter)
Organization: CWI, Amsterdam
Lines: 22

In article <752@rtech.UUCP> jas@rtech.UUCP (Jim Shankland) writes:
 > PARENTHESES AFFECT PRECEDENCE, NOT EVALUATION ORDER.  THESE ARE 2 DIFFERENT
 > THINGS.  To put it another way, parentheses affect the shape of the parse
 > tree for an expression; evaluation order is an order in which the parse
 > tree is walked.
I may be dense, but I do not understand.  If I write a + (b + c) the
parenthesis are just there to affect precedence, the second + has now higher
precedence than the first.  Evaluation order is something different, I do
not mind whether you evaluate a before b or c, or the other way round.
(This silly remark has been put up a number of times.  Parenthesis ought
to affect precedence, but I want an effect on precedence if I write
a + (b + c), just as I want it if I write a * (b + c).  However, the C
language should not provide it because of all those parenthesis coming
up from macros.  Unless of course, the ANSI C-committee decides that
parenthesis from macros are different from normal parenthesis.
{which of course is true, unless your macro ....})

I look, I used parenthesis and braces!
-- 
dik t. winter, cwi, amsterdam, nederland
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