Path: utzoo!utgpu!water!watmath!dalcs!garfield!john13
From: john13@garfield.UUCP (John Russell)
Newsgroups: comp.lang.c
Subject: Re: Implicit testing of 0 (was: == vs =)
Summary: how to make your intentions clear
Message-ID: <4439@garfield.UUCP>
Date: 24 Jan 88 19:52:57 GMT
References: <11216@brl-adm.ARPA> <2111@chinet.UUCP> <4403@garfield.UUCP> <3208@bunker.UUCP> <3484@ihlpf.ATT.COM>
Reply-To: john13@garfield.UUCP (John Russell)
Organization: Memorial University of Newfoundland, St. John's
Lines: 38

(Haven't seen 3208@bunker yet in its entirety so I'll be brief)

>In article <3208@bunker.UUCP> garys@bunker.UUCP (Gary M. Samuelson) writes:
>.1.  I don't find the implicit test for zero "distasteful" -- I find
>.	hard-to-read code distasteful.  Actually, "taste" is irrelevant.
>.	Cost of development and cost of maintenance are.  Hard-to-read
>.	code costs too much.  I enjoy solving puzzles as much as the
>.	next guy, but programmers should be paid to write programs,
>.	not solve puzzles.

Might I propose a solution then?

/* do several assignments to either the success value or 0 if call fails */

if (x = y = z = a = b = c = fn())
...
else	/* I know all my temp variables are set to 0 here */
...

/* test current value of function against expected value */

if (q == fn())	/* or if (fn() == q) which some people prefer */
...

This allows you to save a machine cycle here and there, and do other things
that someone else might find hard to follow, without creating an unreadable
program. I personally find it easier to type out a short comment than to
stretch my fingers for extra parentheses, '!= 0', '!= NULL' etc; I use a single 
key macro to do the /*  */ and leave the cursor in the middle. Positioning 
extra parentheses in the middle of some long expression has bitten me far more 
often than has = vs ==.

John
-- 
"You are lying scum!"
	-- member of Parliament James Fulton was expelled for saying this to
	   Canadian Prime Minister Brian Mulroney; use of the word "lying"
	   was deemed unparliamentary, although the "scum" was acceptable