Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!dewey.soe.berkeley.edu!oster
From: oster@dewey.soe.berkeley.edu (David Phillip Oster)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Initializing automatic arrays
Keywords: MPW-C, LSC, versions 3.0
Message-ID: <28295@ucbvax.BERKELEY.EDU>
Date: 5 Mar 89 21:46:46 GMT
References: <9226@orstcs.CS.ORST.EDU>
Sender: usenet@ucbvax.BERKELEY.EDU
Reply-To: oster@dewey.soe.berkeley.edu.UUCP (David Phillip Oster)
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Organization: School of Education, UC-Berkeley
Lines: 36

In article <9226@orstcs.CS.ORST.EDU> sagen@nucthy.physics.orst.edu (Milt Sagen) writes:
_>#ifdef THINK_C
_>#define  real  double
_>#else
_>#define  real  extended
_>#endif
_>
_>real XFactorial( x )
_>   real x ;
_>{
_>   real  coef[] = (  76.18009173, -86.50532033, 24.01409822
_>                     -1.231739516, 0.120858003e-2, 0.536382e-5 ) ;
_>}

this program has numerous errors, and certainly doesn't do what the
author intended. Notice that Milt uses parentheses to delimit his list of
constants: That makes the whole thing be a constant expression that
returns its last component as its value. So, what he has is equivalent to
real coef[1] = 0.536382e-5;  Note further that even if he had used
squiggly braces, there is a comma missing at the end of the first line, so
he will get a 5 element array of which coef[2] == 24.01409822 - 1.231739516;
The following version version is more correct:
 
real XFactorial( x )real x;{
   static real  coef[] = {  76.18009173, -86.50532033, 24.01409822,
                     -1.231739516, 0.120858003e-2, 0.536382e-5 } ;
}
This version is correct if, as is likely, coef will not change at
runtime.

I am surprised that MPW C passed the original without complaint. I like
compilers to point out errors in my code.

--- David Phillip Oster            --"When we replace the mouse with a pen,
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