# $Id$
#
+use strict;
+
package Julian;
-use Carp;
-use strict;
+use vars qw($VERSION $BRANCH);
+$VERSION = sprintf( "%d.%03d", q$Revision$ =~ /(\d+)\.(\d+)/ );
+$BRANCH = sprintf( "%d.%03d", q$Revision$ =~ /\d+\.\d+\.(\d+)\.(\d+)/ ) || 0;
+$main::build += $VERSION;
+$main::branch += $BRANCH;
+
+
+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;