Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!uunet!igor!rutabaga!jls
From: jls@rutabaga.Rational.COM (Jim Showalter)
Newsgroups: comp.object
Subject: Re: Documenting OO Systems
Keywords: operators
Message-ID: <jls.670567351@rutabaga>
Date: 2 Apr 91 04:42:31 GMT
References: <jls.669768656@rutabaga> <299@orbit.gtephx.UUCP> <1991Mar25.145441.1@happy.colorado.edu> <20106@alice.att.com> <3481@engadm3.csd.mot.com> <DWWX.91Mar25215016@cbnewsk.ATT.COM> <jls.669956827@rutabaga> <1991Mar26.191259.14470@i88.isc.com> <4693@osc.COM> <jl
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%int j (int year, int month, int day) {
%int month_days[12] = {31,28,31,30,31,30,31,31,30,31,30,31};
%if (month<1 || month>12) return 0;
%int leap = !(year%4) && year&400;
%if (day<1 || day>(month_days[month-1] + (month==2 && year))) return 0;
%int dayofmonth = 0;
%for (int i=0; i<month-1; i++) dayofmonth += month_days[i];
%return dayofmonth + day + (month>2 && year);
%}

THIS is readable? I think the problem is more deeply rooted in the
C culture than I thought... (this would garner one of my Ada students
a D minus)

%It becomes immediately apparent not
%only what the function is supposed to do, but that it contains at
%least one error (surely you meant to check (month==2 && leap)).

Yep, you found one of the planted bugs. Now find the other.

P.S. For all those who said what this function does is calculate
     the Julian date: wrong. What it is SUPPOSED to do is calculate
     the Julian date. What it actually does is produce erroneous
     results.

     This might have been easier to see if it had been written better.
--
***** DISCLAIMER: The opinions expressed herein are my own, except in
      the realm of software engineering, in which case I've borrowed
      them from incredibly smart people.