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From: rbutterworth@orchid.UUCP
Newsgroups: comp.lang.c
Subject: Re: *\"LDA\" ok?
Message-ID: <10402@orchid.waterloo.edu>
Date: Wed, 26-Aug-87 12:02:13 EDT
Article-I.D.: orchid.10402
Posted: Wed Aug 26 12:02:13 1987
Date-Received: Fri, 28-Aug-87 02:45:48 EDT
References: <8877@brl-adm.ARPA> <8088@mimsy.UUCP> <1623@tekchips.TEK.COM> <6332@brl-smoke.ARPA>
Organization: U of Waterloo, Ontario
Lines: 37

In article <6332@brl-smoke.ARPA>, gwyn@brl-smoke.ARPA (Doug Gwyn ) writes:
> Perhaps it would help if they were told that strcmp() does NOT test for
> string equality; rather, it compare the lexical ordering of two strings.
> This makes it useful sometimes for the function used with qsort().  The
> test for exact match is simply a common special case.

The biggest problem I've found with my and other's understanding
of strcmp() is its name.  Until you get used to it, "!strcmp()",
"strmcp() != 0", and other such usages are quite non-obvious.

In most cases the function is simply used as a true or false test,
and it isn't obvious that a true comparison should mean that the
strings are different.

If it were named say strdif(), then something like
"if (!strdif(a,b)) ..." or "if (strdif(a,b))" would be much more
readable for the beginner.  i.e. the truth indicates that the
strings were different, something that even beginners should be
able to understand, as opposed to the truth indicating that the
strings were comparable, a concept that isn't all that obvious
to me even after years of use.

The word "compare" says what you want to do with the arguments,
the word "difference" says what result you want.  It's much easier
to think of this particular function in terms of what it returns
rather than in terms of what it does with its arguments.  On the
other hand, functions such as printf() are appropriately named
according to what they do to their arguments, not the value
they return, and so there is much less confusion. 

Of course there isn't much we can do about it now, but this is
something that should be considered when making up names for new
functions.

We speak of "evolving" languages, but somehow I think that if
Darwin had had to contend with the concept of "backward compatibility"
he would have given up.