Path: utzoo!utgpu!watserv1!watmath!att!ima!ima.isc.com
From: karl@ima.isc.com (Karl Heuer)
Newsgroups: comp.lang.c
Subject: Re: # to the nth power
Message-ID: <5240@ima.ima.isc.com>
Date: 5 Nov 90 06:08:53 GMT
References: <90305.005050CJH101@psuvm.psu.edu>
Sender: karl@ima.ima.isc.com
Reply-To: karl@ima.isc.com (Karl Heuer)
Organization: Interactive Systems
Lines: 23
Supersedes: <1990Nov02.060401.17669@dirtydog.ima.isc.com>

In article <90305.005050CJH101@psuvm.psu.edu> CJH101@psuvm.psu.edu (Carl J. Hixon) writes:
>Why am I unable to find an opperator which raises a number to a power.  (The
>fortran equivalent of x**n)

If you look up "exponentiation" in the index to K&R, you'll be directed to a
page that mentions the non-existence of such an operator, and an example
function that implements the integer-to-integer version.  (And, if the K&R was
2nd edition, a mention of the existence of the real-to-real version in the
standard library.)

As to *why*, the usual explanation is that C operators tend to mirror common
hardware instructions, with anything more complex (such as string copy) being
implemented as a library function instead.  This explanation isn't entirely
satisfactory, and in fact I believe C should have had such an operator; but
I'll continue that thread in alt.lang.cfutures.

In article <1990Nov1.232830.17131@NCoast.ORG> catfood@NCoast.ORG (Mark W. Schumann) writes:
>	int result = 1;
>	for (i = exponent; i > 1; i--) result *= root;

Fencepost error.  Should be "i > 0".

Karl W. Z. Heuer (karl@ima.isc.com or uunet!ima!karl), The Walking Lint