# Copyright (c) 2003 Flavio Soibelmann Glock. All rights reserved.
# This program is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.
package DateTime::Span;
use strict;
use DateTime::Set;
use DateTime::SpanSet;
use Params::Validate qw( validate SCALAR BOOLEAN OBJECT CODEREF ARRAYREF );
use vars qw( $VERSION );
use constant INFINITY => DateTime::INFINITY;
use constant NEG_INFINITY => DateTime::NEG_INFINITY;
$VERSION = $DateTime::Set::VERSION;
sub set_time_zone {
my ( $self, $tz ) = @_;
$self->{set} = $self->{set}->iterate(
sub {
my %tmp = %{ $_[0]->{list}[0] };
$tmp{a} = $tmp{a}->clone->set_time_zone( $tz ) if ref $tmp{a};
$tmp{b} = $tmp{b}->clone->set_time_zone( $tz ) if ref $tmp{b};
\%tmp;
}
);
return $self;
}
# note: the constructor must clone its DateTime parameters, such that
# the set elements become immutable
sub from_datetimes {
my $class = shift;
my %args = validate( @_,
{ start =>
{ type => OBJECT,
optional => 1,
},
end =>
{ type => OBJECT,
optional => 1,
},
after =>
{ type => OBJECT,
optional => 1,
},
before =>
{ type => OBJECT,
optional => 1,
},
}
);
my $self = {};
my $set;
die "No arguments given to DateTime::Span->from_datetimes\n"
unless keys %args;
if ( exists $args{start} && exists $args{after} ) {
die "Cannot give both start and after arguments to DateTime::Span->from_datetimes\n";
}
if ( exists $args{end} && exists $args{before} ) {
die "Cannot give both end and before arguments to DateTime::Span->from_datetimes\n";
}
my ( $start, $open_start, $end, $open_end );
( $start, $open_start ) = ( NEG_INFINITY, 0 );
( $start, $open_start ) = ( $args{start}, 0 ) if exists $args{start};
( $start, $open_start ) = ( $args{after}, 1 ) if exists $args{after};
( $end, $open_end ) = ( INFINITY, 0 );
( $end, $open_end ) = ( $args{end}, 0 ) if exists $args{end};
( $end, $open_end ) = ( $args{before}, 1 ) if exists $args{before};
if ( $start > $end ) {
die "Span cannot start after the end in DateTime::Span->from_datetimes\n";
}
$set = Set::Infinite::_recurrence->new( $start, $end );
if ( $start != $end ) {
# remove start, such that we have ">" instead of ">="
$set = $set->complement( $start ) if $open_start;
# remove end, such that we have "<" instead of "<="
$set = $set->complement( $end ) if $open_end;
}
$self->{set} = $set;
bless $self, $class;
return $self;
}
sub from_datetime_and_duration {
my $class = shift;
my %args = @_;
my $key;
my $dt;
# extract datetime parameters
for ( qw( start end before after ) ) {
if ( exists $args{$_} ) {
$key = $_;
$dt = delete $args{$_};
}
}
# extract duration parameters
my $dt_duration;
if ( exists $args{duration} ) {
$dt_duration = $args{duration};
}
else {
$dt_duration = DateTime::Duration->new( %args );
}
# warn "Creating span from $key => ".$dt->datetime." and $dt_duration";
my $other_date;
my $other_key;
if ( $dt_duration->is_positive ) {
if ( $key eq 'end' || $key eq 'before' ) {
$other_key = 'start';
$other_date = $dt->clone->subtract_duration( $dt_duration );
}
else {
$other_key = 'before';
$other_date = $dt->clone->add_duration( $dt_duration );
}
}
else {
if ( $key eq 'end' || $key eq 'before' ) {
$other_key = 'start';
$other_date = $dt->clone->add_duration( $dt_duration );
}
else {
$other_key = 'before';
$other_date = $dt->clone->subtract_duration( $dt_duration );
}
}
# warn "Creating span from $key => ".$dt->datetime." and ".$other_date->datetime;
return $class->new( $key => $dt, $other_key => $other_date );
}
# This method is intentionally not documented. It's really only for
# use by ::Set and ::SpanSet's as_list() and iterator() methods.
sub new {
my $class = shift;
my %args = @_;
# If we find anything _not_ appropriate for from_datetimes, we
# assume it must be for durations, and call this constructor.
# This way, we don't need to hardcode the DateTime::Duration
# parameters.
foreach ( keys %args )
{
return $class->from_datetime_and_duration(%args)
unless /^(?:before|after|start|end)$/;
}
return $class->from_datetimes(%args);
}
sub is_empty_set {
my $set = $_[0];
$set->{set}->is_null;
}
sub clone {
bless {
set => $_[0]->{set}->copy,
}, ref $_[0];
}
# Set::Infinite methods
sub intersection {
my ($set1, $set2) = @_;
my $class = ref($set1);
my $tmp = {}; # $class->new();
$set2 = $set2->as_spanset
if $set2->can( 'as_spanset' );
$set2 = $set2->as_set
if $set2->can( 'as_set' );
$set2 = DateTime::Set->from_datetimes( dates => [ $set2 ] )
unless $set2->can( 'union' );
$tmp->{set} = $set1->{set}->intersection( $set2->{set} );
# intersection() can generate something more complex than a span.
bless $tmp, 'DateTime::SpanSet';
return $tmp;
}
sub intersects {
my ($set1, $set2) = @_;
my $class = ref($set1);
$set2 = $set2->as_spanset
if $set2->can( 'as_spanset' );
$set2 = $set2->as_set
if $set2->can( 'as_set' );
$set2 = DateTime::Set->from_datetimes( dates => [ $set2 ] )
unless $set2->can( 'union' );
return $set1->{set}->intersects( $set2->{set} );
}
sub contains {
my ($set1, $set2) = @_;
my $class = ref($set1);
$set2 = $set2->as_spanset
if $set2->can( 'as_spanset' );
$set2 = $set2->as_set
if $set2->can( 'as_set' );
$set2 = DateTime::Set->from_datetimes( dates => [ $set2 ] )
unless $set2->can( 'union' );
return $set1->{set}->contains( $set2->{set} );
}
sub union {
my ($set1, $set2) = @_;
my $class = ref($set1);
my $tmp = {}; # $class->new();
$set2 = $set2->as_spanset
if $set2->can( 'as_spanset' );
$set2 = $set2->as_set
if $set2->can( 'as_set' );
$set2 = DateTime::Set->from_datetimes( dates => [ $set2 ] )
unless $set2->can( 'union' );
$tmp->{set} = $set1->{set}->union( $set2->{set} );
# union() can generate something more complex than a span.
bless $tmp, 'DateTime::SpanSet';
# # We have to check it's internal structure to find out.
# if ( $#{ $tmp->{set}->{list} } != 0 ) {
# bless $tmp, 'Date::SpanSet';
# }
return $tmp;
}
sub complement {
my ($set1, $set2) = @_;
my $class = ref($set1);
my $tmp = {}; # $class->new;
if (defined $set2) {
$set2 = $set2->as_spanset
if $set2->can( 'as_spanset' );
$set2 = $set2->as_set
if $set2->can( 'as_set' );
$set2 = DateTime::Set->from_datetimes( dates => [ $set2 ] )
unless $set2->can( 'union' );
$tmp->{set} = $set1->{set}->complement( $set2->{set} );
}
else {
$tmp->{set} = $set1->{set}->complement;
}
# complement() can generate something more complex than a span.
bless $tmp, 'DateTime::SpanSet';
# # We have to check it's internal structure to find out.
# if ( $#{ $tmp->{set}->{list} } != 0 ) {
# bless $tmp, 'Date::SpanSet';
# }
return $tmp;
}
sub start {
return DateTime::Set::_fix_datetime( $_[0]->{set}->min );
}
*min = \&start;
sub end {
return DateTime::Set::_fix_datetime( $_[0]->{set}->max );
}
*max = \&end;
sub start_is_open {
# min_a returns info about the set boundary
my ($min, $open) = $_[0]->{set}->min_a;
return $open;
}
sub start_is_closed { $_[0]->start_is_open ? 0 : 1 }
sub end_is_open {
# max_a returns info about the set boundary
my ($max, $open) = $_[0]->{set}->max_a;
return $open;
}
sub end_is_closed { $_[0]->end_is_open ? 0 : 1 }
# span == $self
sub span { @_ }
sub duration {
my $dur;
local $@;
eval {
local $SIG{__DIE__}; # don't want to trap this (rt ticket 5434)
$dur = $_[0]->end->subtract_datetime_absolute( $_[0]->start )
};
return $dur if defined $dur;
return DateTime::Infinite::Future->new -
DateTime::Infinite::Past->new;
}
*size = \&duration;
1;
__END__
=head1 NAME
DateTime::Span - Datetime spans
=head1 SYNOPSIS
use DateTime;
use DateTime::Span;
$date1 = DateTime->new( year => 2002, month => 3, day => 11 );
$date2 = DateTime->new( year => 2003, month => 4, day => 12 );
$set2 = DateTime::Span->from_datetimes( start => $date1, end => $date2 );
# set2 = 2002-03-11 until 2003-04-12
$set = $set1->union( $set2 ); # like "OR", "insert", "both"
$set = $set1->complement( $set2 ); # like "delete", "remove"
$set = $set1->intersection( $set2 ); # like "AND", "while"
$set = $set1->complement; # like "NOT", "negate", "invert"
if ( $set1->intersects( $set2 ) ) { ... # like "touches", "interferes"
if ( $set1->contains( $set2 ) ) { ... # like "is-fully-inside"
# data extraction
$date = $set1->start; # first date of the span
$date = $set1->end; # last date of the span
=head1 DESCRIPTION
C<DateTime::Span> is a module for handling datetime spans, otherwise
known as ranges or periods ("from X to Y, inclusive of all datetimes
in between").
This is different from a C<DateTime::Set>, which is made of individual
datetime points as opposed to a range. There is also a module
C<DateTime::SpanSet> to handle sets of spans.
=head1 METHODS
=over 4
=item * from_datetimes
Creates a new span based on a starting and ending datetime.
A 'closed' span includes its end-dates:
$span = DateTime::Span->from_datetimes( start => $dt1, end => $dt2 );
An 'open' span does not include its end-dates:
$span = DateTime::Span->from_datetimes( after => $dt1, before => $dt2 );
A 'semi-open' span includes one of its end-dates:
$span = DateTime::Span->from_datetimes( start => $dt1, before => $dt2 );
$span = DateTime::Span->from_datetimes( after => $dt1, end => $dt2 );
A span might have just a beginning date, or just an ending date.
These spans end, or start, in an imaginary 'forever' date:
$span = DateTime::Span->from_datetimes( start => $dt1 );
$span = DateTime::Span->from_datetimes( end => $dt2 );
$span = DateTime::Span->from_datetimes( after => $dt1 );
$span = DateTime::Span->from_datetimes( before => $dt2 );
You cannot give both a "start" and "after" argument, nor can you give
both an "end" and "before" argument. Either of these conditions will
cause the C<from_datetimes()> method to die.
To summarize, a datetime passed as either "start" or "end" is included
in the span. A datetime passed as either "after" or "before" is
excluded from the span.
=item * from_datetime_and_duration
Creates a new span.
$span = DateTime::Span->from_datetime_and_duration(
start => $dt1, duration => $dt_dur1 );
$span = DateTime::Span->from_datetime_and_duration(
after => $dt1, hours => 12 );
The new "end of the set" is I<open> by default.
=item * clone
This object method returns a replica of the given object.
=item * set_time_zone( $tz )
This method accepts either a time zone object or a string that can be
passed as the "name" parameter to C<< DateTime::TimeZone->new() >>.
If the new time zone's offset is different from the old time zone,
then the I<local> time is adjusted accordingly.
If the old time zone was a floating time zone, then no adjustments to
the local time are made, except to account for leap seconds. If the
new time zone is floating, then the I<UTC> time is adjusted in order
to leave the local time untouched.
=item * duration
The total size of the set, as a C<DateTime::Duration> object, or as a
scalar containing infinity.
Also available as C<size()>.
=item * start
=item * end
First or last dates in the span.
It is possible that the return value from these methods may be a
C<DateTime::Infinite::Future> or a C<DateTime::Infinite::Past>xs object.
If the set ends C<before> a date C<$dt>, it returns C<$dt>. Note that
in this case C<$dt> is not a set element - but it is a set boundary.
=cut
# scalar containing either negative infinity
# or positive infinity.
=item * start_is_closed
=item * end_is_closed
Returns true if the first or last dates belong to the span ( begin <= x <= end ).
=item * start_is_open
=item * end_is_open
Returns true if the first or last dates are excluded from the span ( begin < x < end ).
=item * union
=item * intersection
=item * complement
Set operations may be performed not only with C<DateTime::Span>
objects, but also with C<DateTime::Set> and C<DateTime::SpanSet>
objects. These set operations always return a C<DateTime::SpanSet>
object.
$set = $span->union( $set2 ); # like "OR", "insert", "both"
$set = $span->complement( $set2 ); # like "delete", "remove"
$set = $span->intersection( $set2 ); # like "AND", "while"
$set = $span->complement; # like "NOT", "negate", "invert"
=item * intersects
=item * contains
These set functions return a boolean value.
if ( $span->intersects( $set2 ) ) { ... # like "touches", "interferes"
if ( $span->contains( $dt ) ) { ... # like "is-fully-inside"
These methods can accept a C<DateTime>, C<DateTime::Set>,
C<DateTime::Span>, or C<DateTime::SpanSet> object as an argument.
=back
=head1 SUPPORT
Support is offered through the C<datetime@perl.org> mailing list.
Please report bugs using rt.cpan.org
=head1 AUTHOR
Flavio Soibelmann Glock <fglock@gmail.com>
The API was developed together with Dave Rolsky and the DateTime Community.
=head1 COPYRIGHT
Copyright (c) 2003-2006 Flavio Soibelmann Glock. All rights reserved.
This program is free software; you can distribute it and/or modify it
under the same terms as Perl itself.
The full text of the license can be found in the LICENSE file
included with this module.
=head1 SEE ALSO
Set::Infinite
For details on the Perl DateTime Suite project please see
L<http://datetime.perl.org>.
=cut