X-Git-Url: http://gb7djk.dxcluster.net/gitweb/gitweb.cgi?a=blobdiff_plain;f=perl%2FJulian.pm;h=2307e08a9d651a6b6a238b90d8af0f8945aabc1e;hb=f0910da57e166acb22e83de4e4b771d175074c80;hp=861f84d441aef14e79d9727b0956bb659e79b99b;hpb=ece0b001419b8e755540eaff4ce3a558fd7d939f;p=spider.git

diff --git a/perl/Julian.pm b/perl/Julian.pm
index 861f84d4..2307e08a 100644
--- a/perl/Julian.pm
+++ b/perl/Julian.pm
@@ -6,95 +6,131 @@
 # $Id$
 #
 
+use strict;
+
 package Julian;
 
-use strict;
+sub alloc($$$)
+{
+	my ($pkg, $year, $thing) = @_;
+	return bless [$year, $thing], ref($pkg)||$pkg;
+}
+
+sub copy
+{
+	my $old = shift;
+	return $old->alloc(@$old);
+}
+
+sub cmp($$)
+{
+	my ($a, $b) = @_;
+	return $a->[1] - $b->[1] if ($a->[0] == $b->[0]);
+	return $a->[0] - $b->[0];
+}
+
+sub year
+{
+	return $_[0]->[0];
+}
+
+sub thing
+{
+	return $_[0]->[1];
+}
+
+package Julian::Day;
+
+use vars qw(@ISA);
+@ISA = qw(Julian);
 
 my @days = (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
 
-# take a unix date and transform it into a julian day (ie (1998, 13) = 13th day of 1998)
-sub unixtoj
+# is it a leap year?
+sub _isleap
 {
-	my $t = shift;
-	my ($year, $day) = (gmtime($t))[5,7];
-	
-	$year += 1900;
-	return ($year, $day+1);
+	my $year = shift;
+	return ($year % 4 == 0 && ($year % 100 != 0 || $year % 400 == 0)) ? 1 : 0; 
 }
 
-# take a unix and return a julian month from it
-sub unixtojm
+sub new($$)
 {
+	my $pkg = shift;
 	my $t = shift;
-	my ($mon, $year) = (gmtime($t))[4..5];
-
+	my ($year, $day) = (gmtime($t))[5,7];
 	$year += 1900;
-	return ($year, $mon + 1);
+	return $pkg->SUPER::alloc($year, $day+1);
 }
 
 # take a julian date and subtract a number of days from it, returning the julian date
-sub sub
+sub sub($$)
 {
-	my ($year, $day, $amount) = @_;
-	my $diny = isleap($year) ? 366 : 365;
-	$day -= $amount;
-	while ($day <= 0) {
-		$day += $diny;
-		$year -= 1;
-		$diny = isleap($year) ? 366 : 365;
+	my ($old, $amount) = @_;
+	my $self = $old->copy;
+	my $diny = _isleap($self->[0]) ? 366 : 365;
+	$self->[1] -= $amount;
+	while ($self->[1] <= 0) {
+		$self->[1] += $diny;
+		$self->[0] -= 1;
+		$diny = _isleap($self->[0]) ? 366 : 365;
 	}
-	return ($year, $day);
+	return $self;
 }
 
-sub add
+sub add($$)
 {
-	my ($year, $day, $amount) = @_;
-	my $diny = isleap($year) ? 366 : 365;
-	$day += $amount;
-	while ($day > $diny) {
-		$day -= $diny;
-		$year += 1;
-		$diny = isleap($year) ? 366 : 365;
+	my ($old, $amount) = @_;
+	my $self = $old->copy;
+	my $diny = _isleap($self->[0]) ? 366 : 365;
+	$self->[1] += $amount;
+	while ($self->[1] > $diny) {
+		$self->[1] -= $diny;
+		$self->[0] += 1;
+		$diny = _isleap($self->[0]) ? 366 : 365;
 	}
-	return ($year, $day);
+	return $self;
 } 
 
-# take a julian month and subtract a number of months from it, returning the julian month
-sub subm
+package Julian::Month;
+
+use vars qw(@ISA);
+@ISA = qw(Julian);
+
+sub new($$)
 {
-	my ($year, $mon, $amount) = @_;
-	$mon -= $amount;
-	while ($mon <= 0) {
-		$mon += 12;
-		$year -= 1;
-	}
-	return ($year, $mon);
+	my $pkg = shift;
+	my $t = shift;
+	my ($mon, $year) = (gmtime($t))[4,5];
+	$year += 1900;
+	return $pkg->SUPER::alloc($year, $mon+1);
 }
 
-sub addm
+# take a julian month and subtract a number of months from it, returning the julian month
+sub sub($$)
 {
-	my ($year, $mon, $amount) = @_;
-	$mon += $amount;
-	while ($mon > 12) {
-		$mon -= 12;
-		$year += 1;
+	my ($old, $amount) = @_;
+	my $self = $old->copy;
+	
+	$self->[1] -= $amount;
+	while ($self->[1] <= 0) {
+		$self->[1] += 12;
+		$self->[0] -= 1;
 	}
-	return ($year, $mon);
-} 
-
-sub cmp
-{
-	my ($y1, $d1, $y2, $d2) = @_;
-	return $d1 - $d2 if ($y1 == $y2);
-	return $y1 - $y2;
+	return $self;
 }
 
-# is it a leap year?
-sub isleap
+sub add($$)
 {
-	my $year = shift;
-	return ($year % 4 == 0 && ($year % 100 != 0 || $year % 400 == 0)) ? 1 : 0; 
-}
+	my ($old, $amount) = @_;
+	my $self = $old->copy;
+
+	$self->[1] += $amount;
+	while ($self->[1] > 12) {
+		$self->[1] -= 12;
+		$self->[0] += 1;
+	}
+	return $self;
+} 
 
 
 1;