Path: utzoo!mnetor!uunet!husc6!yale!bunker!garys
From: garys@bunker.UUCP (Gary M. Samuelson)
Newsgroups: comp.lang.c
Subject: Re: == vs =
Message-ID: <3208@bunker.UUCP>
Date: 20 Jan 88 14:26:11 GMT
References: <11216@brl-adm.ARPA> <2111@chinet.UUCP> <4403@garfield.UUCP>
Reply-To: garys@bunker.UUCP (Gary M. Samuelson)
Organization: Bunker Ramo, an Olivetti Company, Shelton, Ct
Lines: 43

In article <4403@garfield.UUCP> john13@garfield.UUCP (John Russell) writes:
>I made the = mistake a couple of times very early in the C learning process.
>But since I convinced myself that "if (x = fn())" was both a valid and
>useful construct, and put it to use in code, the *meaning* of each has become
>very apparent so that I use the proper form automatically.
>
>People who find the implicit test for zero distasteful (I get the feeling
>many of them never programmed in assembler) may never be comfortable with
>'=='. But for people who like it for its conciseness, the chances of using
>the wrong symbol due to a typo should be no greater than typing "mian" instead
>of "main".

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.

2.  It is irrelevant whether I have programmed in assembly.  As it
	happens, I have.  I'm very good at it, and I write both
	assembly and C according to the "write for the reader"
	principle.

3.  I don't buy the "conciseness" argument -- In the first place,
	1 character is not significantly more concise than 2.  In
	the second, "conciseness" is only a virtue, in my opinion,
	to the extent that it provides readability.

4.  While it may be true that typing "mian" for "main" is as likely as
	typing "=" for "==", the linker will tell me that I mispelled
	"main" by reporting "undefined symbol."  Neither the compiler,
	the linker, nor lint (of which I am an ardent advocate) will
	tell me if "=" should be "==".

5.  When I see "if (x = fn())", I know what it means, but sometimes I
	am not sure whether the author meant "if (x = fn())" or
	"if (x == fn())".  I spend a lot of time trying to figure out
	what other programmers meant, even after I figure out what
	they wrote.  "if( (x = fn()) != 0 )" is longer, but it is
	totally unambiguous to both the author and the (human) reader.

Gary Samuelson