+++ /dev/null
-
-package DateTime::Set;
-
-use strict;
-use Carp;
-use Params::Validate qw( validate SCALAR BOOLEAN OBJECT CODEREF ARRAYREF );
-use DateTime 0.12; # this is for version checking only
-use DateTime::Duration;
-use DateTime::Span;
-use Set::Infinite 0.59;
-use Set::Infinite::_recurrence;
-
-use vars qw( $VERSION );
-
-use constant INFINITY => 100 ** 100 ** 100 ;
-use constant NEG_INFINITY => -1 * (100 ** 100 ** 100);
-
-BEGIN {
- $VERSION = '0.28';
-}
-
-
-sub _fix_datetime {
- # internal function -
- # (not a class method)
- #
- # checks that the parameter is an object, and
- # also protects the object against mutation
-
- return $_[0]
- unless defined $_[0]; # error
- return $_[0]->clone
- if ref( $_[0] ); # "immutable" datetime
- return DateTime::Infinite::Future->new
- if $_[0] == INFINITY; # Inf
- return DateTime::Infinite::Past->new
- if $_[0] == NEG_INFINITY; # -Inf
- return $_[0]; # error
-}
-
-sub _fix_return_datetime {
- my ( $dt, $dt_arg ) = @_;
-
- # internal function -
- # (not a class method)
- #
- # checks that the returned datetime has the same
- # time zone as the parameter
-
- # TODO: set locale
-
- return unless $dt;
- return unless $dt_arg;
- if ( $dt_arg->can('time_zone_long_name') &&
- !( $dt_arg->time_zone_long_name eq 'floating' ) )
- {
- $dt->set_time_zone( $dt_arg->time_zone );
- }
- return $dt;
-}
-
-sub iterate {
- # deprecated method - use map() or grep() instead
- my ( $self, $callback ) = @_;
- my $class = ref( $self );
- my $return = $class->empty_set;
- $return->{set} = $self->{set}->iterate(
- sub {
- my $min = $_[0]->min;
- $callback->( $min->clone ) if ref($min);
- }
- );
- $return;
-}
-
-sub map {
- my ( $self, $callback ) = @_;
- my $class = ref( $self );
- die "The callback parameter to map() must be a subroutine reference"
- unless ref( $callback ) eq 'CODE';
- my $return = $class->empty_set;
- $return->{set} = $self->{set}->iterate(
- sub {
- local $_ = $_[0]->min;
- next unless ref( $_ );
- $_ = $_->clone;
- my @list = $callback->();
- my $set = Set::Infinite::_recurrence->new();
- $set = $set->union( $_ ) for @list;
- return $set;
- }
- );
- $return;
-}
-
-sub grep {
- my ( $self, $callback ) = @_;
- my $class = ref( $self );
- die "The callback parameter to grep() must be a subroutine reference"
- unless ref( $callback ) eq 'CODE';
- my $return = $class->empty_set;
- $return->{set} = $self->{set}->iterate(
- sub {
- local $_ = $_[0]->min;
- next unless ref( $_ );
- $_ = $_->clone;
- my $result = $callback->();
- return $_ if $result;
- return;
- }
- );
- $return;
-}
-
-sub add { return shift->add_duration( DateTime::Duration->new(@_) ) }
-
-sub subtract { return shift->subtract_duration( DateTime::Duration->new(@_) ) }
-
-sub subtract_duration { return $_[0]->add_duration( $_[1]->inverse ) }
-
-sub add_duration {
- my ( $self, $dur ) = @_;
- $dur = $dur->clone; # $dur must be "immutable"
-
- $self->{set} = $self->{set}->iterate(
- sub {
- my $min = $_[0]->min;
- $min->clone->add_duration( $dur ) if ref($min);
- },
- backtrack_callback => sub {
- my ( $min, $max ) = ( $_[0]->min, $_[0]->max );
- if ( ref($min) )
- {
- $min = $min->clone;
- $min->subtract_duration( $dur );
- }
- if ( ref($max) )
- {
- $max = $max->clone;
- $max->subtract_duration( $dur );
- }
- return Set::Infinite::_recurrence->new( $min, $max );
- },
- );
- $self;
-}
-
-sub set_time_zone {
- my ( $self, $tz ) = @_;
-
- $self->{set} = $self->{set}->iterate(
- sub {
- my $min = $_[0]->min;
- $min->clone->set_time_zone( $tz ) if ref($min);
- },
- backtrack_callback => sub {
- my ( $min, $max ) = ( $_[0]->min, $_[0]->max );
- if ( ref($min) )
- {
- $min = $min->clone;
- $min->set_time_zone( $tz );
- }
- if ( ref($max) )
- {
- $max = $max->clone;
- $max->set_time_zone( $tz );
- }
- return Set::Infinite::_recurrence->new( $min, $max );
- },
- );
- $self;
-}
-
-sub set {
- my $self = shift;
- my %args = validate( @_,
- { locale => { type => SCALAR | OBJECT,
- default => undef },
- }
- );
- $self->{set} = $self->{set}->iterate(
- sub {
- my $min = $_[0]->min;
- $min->clone->set( %args ) if ref($min);
- },
- );
- $self;
-}
-
-sub from_recurrence {
- my $class = shift;
-
- my %args = @_;
- my %param;
-
- # Parameter renaming, such that we can use either
- # recurrence => xxx or next => xxx, previous => xxx
- $param{next} = delete $args{recurrence} || delete $args{next};
- $param{previous} = delete $args{previous};
-
- $param{span} = delete $args{span};
- # they might be specifying a span using begin / end
- $param{span} = DateTime::Span->new( %args ) if keys %args;
-
- my $self = {};
-
- die "Not enough arguments in from_recurrence()"
- unless $param{next} || $param{previous};
-
- if ( ! $param{previous} )
- {
- my $data = {};
- $param{previous} =
- sub {
- _callback_previous ( _fix_datetime( $_[0] ), $param{next}, $data );
- }
- }
- else
- {
- my $previous = $param{previous};
- $param{previous} =
- sub {
- $previous->( _fix_datetime( $_[0] ) );
- }
- }
-
- if ( ! $param{next} )
- {
- my $data = {};
- $param{next} =
- sub {
- _callback_next ( _fix_datetime( $_[0] ), $param{previous}, $data );
- }
- }
- else
- {
- my $next = $param{next};
- $param{next} =
- sub {
- $next->( _fix_datetime( $_[0] ) );
- }
- }
-
- my ( $min, $max );
- $max = $param{previous}->( DateTime::Infinite::Future->new );
- $min = $param{next}->( DateTime::Infinite::Past->new );
- $max = INFINITY if $max->is_infinite;
- $min = NEG_INFINITY if $min->is_infinite;
-
- my $base_set = Set::Infinite::_recurrence->new( $min, $max );
- $base_set = $base_set->intersection( $param{span}->{set} )
- if $param{span};
-
- # warn "base set is $base_set\n";
-
- my $data = {};
- $self->{set} =
- $base_set->_recurrence(
- $param{next},
- $param{previous},
- $data,
- );
- bless $self, $class;
-
- return $self;
-}
-
-sub from_datetimes {
- my $class = shift;
- my %args = validate( @_,
- { dates =>
- { type => ARRAYREF,
- },
- }
- );
- my $self = {};
- $self->{set} = Set::Infinite::_recurrence->new;
- # possible optimization: sort datetimes and use "push"
- for( @{ $args{dates} } )
- {
- # DateTime::Infinite objects are not welcome here,
- # but this is not enforced (it does't hurt)
-
- carp "The 'dates' argument to from_datetimes() must only contain ".
- "datetime objects"
- unless UNIVERSAL::can( $_, 'utc_rd_values' );
-
- $self->{set} = $self->{set}->union( $_->clone );
- }
-
- bless $self, $class;
- return $self;
-}
-
-sub empty_set {
- my $class = shift;
-
- return bless { set => Set::Infinite::_recurrence->new }, $class;
-}
-
-sub clone {
- my $self = bless { %{ $_[0] } }, ref $_[0];
- $self->{set} = $_[0]->{set}->copy;
- return $self;
-}
-
-# default callback that returns the
-# "previous" value in a callback recurrence.
-#
-# This is used to simulate a 'previous' callback,
-# when then 'previous' argument in 'from_recurrence' is missing.
-#
-sub _callback_previous {
- my ($value, $callback_next, $callback_info) = @_;
- my $previous = $value->clone;
-
- return $value if $value->is_infinite;
-
- my $freq = $callback_info->{freq};
- unless (defined $freq)
- {
- # This is called just once, to setup the recurrence frequency
- my $previous = $callback_next->( $value );
- my $next = $callback_next->( $previous );
- $freq = 2 * ( $previous - $next );
- # save it for future use with this same recurrence
- $callback_info->{freq} = $freq;
- }
-
- $previous->add_duration( $freq );
- $previous = $callback_next->( $previous );
- if ($previous >= $value)
- {
- # This error happens if the event frequency oscilates widely
- # (more than 100% of difference from one interval to next)
- my @freq = $freq->deltas;
- print STDERR "_callback_previous: Delta components are: @freq\n";
- warn "_callback_previous: iterator can't find a previous value, got ".
- $previous->ymd." after ".$value->ymd;
- }
- my $previous1;
- while (1)
- {
- $previous1 = $previous->clone;
- $previous = $callback_next->( $previous );
- return $previous1 if $previous >= $value;
- }
-}
-
-# default callback that returns the
-# "next" value in a callback recurrence.
-#
-# This is used to simulate a 'next' callback,
-# when then 'next' argument in 'from_recurrence' is missing.
-#
-sub _callback_next {
- my ($value, $callback_previous, $callback_info) = @_;
- my $next = $value->clone;
-
- return $value if $value->is_infinite;
-
- my $freq = $callback_info->{freq};
- unless (defined $freq)
- {
- # This is called just once, to setup the recurrence frequency
- my $next = $callback_previous->( $value );
- my $previous = $callback_previous->( $next );
- $freq = 2 * ( $next - $previous );
- # save it for future use with this same recurrence
- $callback_info->{freq} = $freq;
- }
-
- $next->add_duration( $freq );
- $next = $callback_previous->( $next );
- if ($next <= $value)
- {
- # This error happens if the event frequency oscilates widely
- # (more than 100% of difference from one interval to next)
- my @freq = $freq->deltas;
- print STDERR "_callback_next: Delta components are: @freq\n";
- warn "_callback_next: iterator can't find a previous value, got ".
- $next->ymd." before ".$value->ymd;
- }
- my $next1;
- while (1)
- {
- $next1 = $next->clone;
- $next = $callback_previous->( $next );
- return $next1 if $next >= $value;
- }
-}
-
-sub iterator {
- my $self = shift;
-
- my %args = @_;
- my $span;
- $span = delete $args{span};
- $span = DateTime::Span->new( %args ) if %args;
-
- return $self->intersection( $span ) if $span;
- return $self->clone;
-}
-
-
-# next() gets the next element from an iterator()
-# next( $dt ) returns the next element after a datetime.
-sub next {
- my $self = shift;
- return undef unless ref( $self->{set} );
-
- if ( @_ )
- {
- if ( $self->{set}->_is_recurrence )
- {
- return _fix_return_datetime(
- $self->{set}->{param}[0]->( $_[0] ), $_[0] );
- }
- else
- {
- my $span = DateTime::Span->from_datetimes( after => $_[0] );
- return _fix_return_datetime(
- $self->intersection( $span )->next, $_[0] );
- }
- }
-
- my ($head, $tail) = $self->{set}->first;
- $self->{set} = $tail;
- return $head->min if defined $head;
- return $head;
-}
-
-# previous() gets the last element from an iterator()
-# previous( $dt ) returns the previous element before a datetime.
-sub previous {
- my $self = shift;
- return undef unless ref( $self->{set} );
-
- if ( @_ )
- {
- if ( $self->{set}->_is_recurrence )
- {
- return _fix_return_datetime(
- $self->{set}->{param}[1]->( $_[0] ), $_[0] );
- }
- else
- {
- my $span = DateTime::Span->from_datetimes( before => $_[0] );
- return _fix_return_datetime(
- $self->intersection( $span )->previous, $_[0] );
- }
- }
-
- my ($head, $tail) = $self->{set}->last;
- $self->{set} = $tail;
- return $head->max if defined $head;
- return $head;
-}
-
-# "current" means less-or-equal to a datetime
-sub current {
- my $self = shift;
-
- return undef unless ref( $self->{set} );
-
- if ( $self->{set}->_is_recurrence )
- {
- my $tmp = $self->next( $_[0] );
- return $self->previous( $tmp );
- }
-
- return $_[0] if $self->contains( $_[0] );
- $self->previous( $_[0] );
-}
-
-sub closest {
- my $self = shift;
- # return $_[0] if $self->contains( $_[0] );
- my $dt1 = $self->current( $_[0] );
- my $dt2 = $self->next( $_[0] );
-
- return $dt2 unless defined $dt1;
- return $dt1 unless defined $dt2;
-
- my $delta = $_[0] - $dt1;
- return $dt1 if ( $dt2 - $delta ) >= $_[0];
-
- return $dt2;
-}
-
-sub as_list {
- my $self = shift;
- return undef unless ref( $self->{set} );
-
- my %args = @_;
- my $span;
- $span = delete $args{span};
- $span = DateTime::Span->new( %args ) if %args;
-
- my $set = $self->clone;
- $set = $set->intersection( $span ) if $span;
-
- return if $set->{set}->is_null; # nothing = empty
-
- # Note: removing this line means we may end up in an infinite loop!
- ## return undef if $set->{set}->is_too_complex; # undef = no begin/end
-
- return undef
- if $set->max->is_infinite ||
- $set->min->is_infinite;
-
- my @result;
- my $next = $self->min;
- if ( $span ) {
- my $next1 = $span->min;
- $next = $next1 if $next1 && $next1 > $next;
- $next = $self->current( $next );
- }
- my $last = $self->max;
- if ( $span ) {
- my $last1 = $span->max;
- $last = $last1 if $last1 && $last1 < $last;
- }
- do {
- push @result, $next if !$span || $span->contains($next);
- $next = $self->next( $next );
- }
- while $next && $next <= $last;
- return @result;
-}
-
-sub intersection {
- my ($set1, $set2) = ( shift, shift );
- my $class = ref($set1);
- my $tmp = $class->empty_set();
- $set2 = $set2->as_set
- if $set2->can( 'as_set' );
- $set2 = $class->from_datetimes( dates => [ $set2, @_ ] )
- unless $set2->can( 'union' );
- $tmp->{set} = $set1->{set}->intersection( $set2->{set} );
- return $tmp;
-}
-
-sub intersects {
- my ($set1, $set2) = ( shift, shift );
- my $class = ref($set1);
- $set2 = $set2->as_set
- if $set2->can( 'as_set' );
- unless ( $set2->can( 'union' ) )
- {
- if ( $set1->{set}->_is_recurrence )
- {
- for ( $set2, @_ )
- {
- return 1 if $set1->current( $_ ) == $_;
- }
- return 0;
- }
- $set2 = $class->from_datetimes( dates => [ $set2, @_ ] )
- }
- return $set1->{set}->intersects( $set2->{set} );
-}
-
-sub contains {
- my ($set1, $set2) = ( shift, shift );
- my $class = ref($set1);
- $set2 = $set2->as_set
- if $set2->can( 'as_set' );
- unless ( $set2->can( 'union' ) )
- {
- if ( $set1->{set}->_is_recurrence )
- {
- for ( $set2, @_ )
- {
- return 0 unless $set1->current( $_ ) == $_;
- }
- return 1;
- }
- $set2 = $class->from_datetimes( dates => [ $set2, @_ ] )
- }
- return $set1->{set}->contains( $set2->{set} );
-}
-
-sub union {
- my ($set1, $set2) = ( shift, shift );
- my $class = ref($set1);
- my $tmp = $class->empty_set();
- $set2 = $set2->as_set
- if $set2->can( 'as_set' );
- $set2 = $class->from_datetimes( dates => [ $set2, @_ ] )
- unless $set2->can( 'union' );
- $tmp->{set} = $set1->{set}->union( $set2->{set} );
- bless $tmp, 'DateTime::SpanSet'
- if $set2->isa('DateTime::Span') or $set2->isa('DateTime::SpanSet');
- return $tmp;
-}
-
-sub complement {
- my ($set1, $set2) = ( shift, shift );
- my $class = ref($set1);
- my $tmp = $class->empty_set();
- if (defined $set2)
- {
- $set2 = $set2->as_set
- if $set2->can( 'as_set' );
- $set2 = $class->from_datetimes( dates => [ $set2, @_ ] )
- unless $set2->can( 'union' );
- # TODO: "compose complement";
- $tmp->{set} = $set1->{set}->complement( $set2->{set} );
- }
- else
- {
- $tmp->{set} = $set1->{set}->complement;
- bless $tmp, 'DateTime::SpanSet';
- }
- return $tmp;
-}
-
-sub min {
- return _fix_datetime( $_[0]->{set}->min );
-}
-
-sub max {
- return _fix_datetime( $_[0]->{set}->max );
-}
-
-# returns a DateTime::Span
-sub span {
- my $set = $_[0]->{set}->span;
- my $self = bless { set => $set }, 'DateTime::Span';
- return $self;
-}
-
-sub count {
- my ($self) = shift;
- return undef unless ref( $self->{set} );
-
- my %args = @_;
- my $span;
- $span = delete $args{span};
- $span = DateTime::Span->new( %args ) if %args;
-
- my $set = $self->clone;
- $set = $set->intersection( $span ) if $span;
-
- return $set->{set}->count
- unless $set->{set}->is_too_complex;
-
- return undef
- if $set->max->is_infinite ||
- $set->min->is_infinite;
-
- my $count = 0;
- my $iter = $set->iterator;
- $count++ while $iter->next;
- return $count;
-}
-
-1;
-
-__END__
-
-=head1 NAME
-
-DateTime::Set - Datetime sets and set math
-
-=head1 SYNOPSIS
-
- use DateTime;
- use DateTime::Set;
-
- $date1 = DateTime->new( year => 2002, month => 3, day => 11 );
- $set1 = DateTime::Set->from_datetimes( dates => [ $date1 ] );
- # set1 = 2002-03-11
-
- $date2 = DateTime->new( year => 2003, month => 4, day => 12 );
- $set2 = DateTime::Set->from_datetimes( dates => [ $date1, $date2 ] );
- # set2 = 2002-03-11, and 2003-04-12
-
- $date3 = DateTime->new( year => 2003, month => 4, day => 1 );
- print $set2->next( $date3 )->ymd; # 2003-04-12
- print $set2->previous( $date3 )->ymd; # 2002-03-11
- print $set2->current( $date3 )->ymd; # 2002-03-11
- print $set2->closest( $date3 )->ymd; # 2003-04-12
-
- # a 'monthly' recurrence:
- $set = DateTime::Set->from_recurrence(
- recurrence => sub {
- return $_[0] if $_[0]->is_infinite;
- return $_[0]->truncate( to => 'month' )->add( months => 1 )
- },
- span => $date_span1, # optional span
- );
-
- $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->min; # first date of the set
- $date = $set1->max; # last date of the set
-
- $iter = $set1->iterator;
- while ( $dt = $iter->next ) {
- print $dt->ymd;
- };
-
-=head1 DESCRIPTION
-
-DateTime::Set is a module for datetime sets. It can be used to handle
-two different types of sets.
-
-The first is a fixed set of predefined datetime objects. For example,
-if we wanted to create a set of datetimes containing the birthdays of
-people in our family for the current year.
-
-The second type of set that it can handle is one based on a
-recurrence, such as "every Wednesday", or "noon on the 15th day of
-every month". This type of set can have fixed starting and ending
-datetimes, but neither is required. So our "every Wednesday set"
-could be "every Wednesday from the beginning of time until the end of
-time", or "every Wednesday after 2003-03-05 until the end of time", or
-"every Wednesday between 2003-03-05 and 2004-01-07".
-
-This module also supports set math operations, so you do things like
-create a new set from the union or difference of two sets, check
-whether a datetime is a member of a given set, etc.
-
-This is different from a C<DateTime::Span>, which handles a continuous
-range as opposed to individual datetime points. There is also a module
-C<DateTime::SpanSet> to handle sets of spans.
-
-=head1 METHODS
-
-=over 4
-
-=item * from_datetimes
-
-Creates a new set from a list of datetimes.
-
- $dates = DateTime::Set->from_datetimes( dates => [ $dt1, $dt2, $dt3 ] );
-
-The datetimes can be objects from class C<DateTime>, or from a
-C<DateTime::Calendar::*> class.
-
-C<DateTime::Infinite::*> objects are not valid set members.
-
-=item * from_recurrence
-
-Creates a new set specified via a "recurrence" callback.
-
- $months = DateTime::Set->from_recurrence(
- span => $dt_span_this_year, # optional span
- recurrence => sub {
- return $_[0]->truncate( to => 'month' )->add( months => 1 )
- },
- );
-
-The C<span> parameter is optional. It must be a C<DateTime::Span> object.
-
-The span can also be specified using C<begin> / C<after> and C<before>
-/ C<end> parameters, as in the C<DateTime::Span> constructor. In this
-case, if there is a C<span> parameter it will be ignored.
-
- $months = DateTime::Set->from_recurrence(
- after => $dt_now,
- recurrence => sub {
- return $_[0]->truncate( to => 'month' )->add( months => 1 );
- },
- );
-
-The recurrence function will be passed a single parameter, a datetime
-object. The parameter can be an object from class C<DateTime>, or from
-one of the C<DateTime::Calendar::*> classes. The parameter can also
-be a C<DateTime::Infinite::Future> or a C<DateTime::Infinite::Past>
-object.
-
-The recurrence must return the I<next> event after that object. There
-is no guarantee as to what the returned object will be set to, only
-that it will be greater than the object passed to the recurrence.
-
-If there are no more datetimes after the given parameter, then the
-recurrence function should return C<DateTime::Infinite::Future>.
-
-It is ok to modify the parameter C<$_[0]> inside the recurrence
-function. There are no side-effects.
-
-For example, if you wanted a recurrence that generated datetimes in
-increments of 30 seconds, it would look like this:
-
- sub every_30_seconds {
- my $dt = shift;
- if ( $dt->second < 30 ) {
- return $dt->truncate( to => 'minute' )->add( seconds => 30 );
- } else {
- return $dt->truncate( to => 'minute' )->add( minutes => 1 );
- }
- }
-
-Note that this recurrence takes leap seconds into account. Consider
-using C<truncate()> in this manner to avoid complicated arithmetic
-problems!
-
-It is also possible to create a recurrence by specifying either or both
-of 'next' and 'previous' callbacks.
-
-The callbacks can return C<DateTime::Infinite::Future> and
-C<DateTime::Infinite::Past> objects, in order to define I<bounded
-recurrences>. In this case, both 'next' and 'previous' callbacks must
-be defined:
-
- # "monthly from $dt until forever"
-
- my $months = DateTime::Set->from_recurrence(
- next => sub {
- return $dt if $_[0] < $dt;
- $_[0]->truncate( to => 'month' );
- $_[0]->add( months => 1 );
- return $_[0];
- },
- previous => sub {
- my $param = $_[0]->clone;
- $_[0]->truncate( to => 'month' );
- $_[0]->subtract( months => 1 ) if $_[0] == $param;
- return $_[0] if $_[0] >= $dt;
- return DateTime::Infinite::Past->new;
- },
- );
-
-Bounded recurrences are easier to write using C<span> parameters. See above.
-
-See also C<DateTime::Event::Recurrence> and the other
-C<DateTime::Event::*> factory modules for generating specialized
-recurrences, such as sunrise and sunset times, and holidays.
-
-=item * empty_set
-
-Creates a new empty set.
-
- $set = DateTime::Set->empty_set;
- print "empty set" unless defined $set->max;
-
-=item * clone
-
-This object method returns a replica of the given object.
-
-C<clone> is useful if you want to apply a transformation to a set,
-but you want to keep the previous value:
-
- $set2 = $set1->clone;
- $set2->add_duration( year => 1 ); # $set1 is unaltered
-
-=item * add_duration( $duration )
-
-This method adds the specified duration to every element of the set.
-
- $dt_dur = new DateTime::Duration( year => 1 );
- $set->add_duration( $dt_dur );
-
-The original set is modified. If you want to keep the old values use:
-
- $new_set = $set->clone->add_duration( $dt_dur );
-
-=item * add
-
-This method is syntactic sugar around the C<add_duration()> method.
-
- $meetings_2004 = $meetings_2003->clone->add( years => 1 );
-
-=item * subtract_duration( $duration_object )
-
-When given a C<DateTime::Duration> object, this method simply calls
-C<invert()> on that object and passes that new duration to the
-C<add_duration> method.
-
-=item * subtract( DateTime::Duration->new parameters )
-
-Like C<add()>, this is syntactic sugar for the C<subtract_duration()>
-method.
-
-=item * set_time_zone( $tz )
-
-This method will attempt to apply the C<set_time_zone> method to every
-datetime in the set.
-
-=item * set( locale => .. )
-
-This method can be used to change the C<locale> of a datetime set.
-
-=item * min
-
-=item * max
-
-The first and last C<DateTime> in the set. These methods may return
-C<undef> if the set is empty. It is also possible that these methods
-may return a C<DateTime::Infinite::Past> or
-C<DateTime::Infinite::Future> object.
-
-These methods return just a I<copy> of the actual boundary value.
-If you modify the result, the set will not be modified.
-
-=item * span
-
-Returns the total span of the set, as a C<DateTime::Span> object.
-
-=item * iterator / next / previous
-
-These methods can be used to iterate over the datetimes in a set.
-
- $iter = $set1->iterator;
- while ( $dt = $iter->next ) {
- print $dt->ymd;
- }
-
- # iterate backwards
- $iter = $set1->iterator;
- while ( $dt = $iter->previous ) {
- print $dt->ymd;
- }
-
-The boundaries of the iterator can be limited by passing it a C<span>
-parameter. This should be a C<DateTime::Span> object which delimits
-the iterator's boundaries. Optionally, instead of passing an object,
-you can pass any parameters that would work for one of the
-C<DateTime::Span> class's constructors, and an object will be created
-for you.
-
-Obviously, if the span you specify is not restricted both at the start
-and end, then your iterator may iterate forever, depending on the
-nature of your set. User beware!
-
-The C<next()> or C<previous()> method will return C<undef> when there
-are no more datetimes in the iterator.
-
-=item * as_list
-
-Returns the set elements as a list of C<DateTime> objects. Just as
-with the C<iterator()> method, the C<as_list()> method can be limited
-by a span.
-
- my @dt = $set->as_list( span => $span );
-
-Applying C<as_list()> to a large recurrence set is a very expensive
-operation, both in CPU time and in the memory used. If you I<really>
-need to extract elements from a large set, you can limit the set with
-a shorter span:
-
- my @short_list = $large_set->as_list( span => $short_span );
-
-For I<infinite> sets, C<as_list()> will return C<undef>. Please note
-that this is explicitly not an empty list, since an empty list is a
-valid return value for empty sets!
-
-=item * count
-
-Returns a count of C<DateTime> objects in the set. Just as with the
-C<iterator()> method, the C<count()> method can be limited by a span.
-
- defined( my $n = $set->count) or die "can't count";
-
- my $n = $set->count( span => $span );
- die "can't count" unless defined $n;
-
-Applying C<count()> to a large recurrence set is a very expensive
-operation, both in CPU time and in the memory used. If you I<really>
-need to count elements from a large set, you can limit the set with a
-shorter span:
-
- my $count = $large_set->count( span => $short_span );
-
-For I<infinite> sets, C<count()> will return C<undef>. Please note
-that this is explicitly not a scalar zero, since a zero count is a
-valid return value for empty sets!
-
-=item * union
-
-=item * intersection
-
-=item * complement
-
-These set operation methods can accept a C<DateTime> list, a
-C<DateTime::Set>, a C<DateTime::Span>, or a C<DateTime::SpanSet>
-object as an argument.
-
- $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"
-
-The C<union> of a C<DateTime::Set> with a C<DateTime::Span> or a
-C<DateTime::SpanSet> object returns a C<DateTime::SpanSet> object.
-
-If C<complement> is called without any arguments, then the result is a
-C<DateTime::SpanSet> object representing the spans between each of the
-set's elements. If complement is given an argument, then the return
-value is a C<DateTime::Set> object representing the I<set difference>
-between the sets.
-
-All other operations will always return a C<DateTime::Set>.
-
-=item * intersects
-
-=item * contains
-
-These set operations result in a boolean value.
-
- if ( $set1->intersects( $set2 ) ) { ... # like "touches", "interferes"
- if ( $set1->contains( $dt ) ) { ... # like "is-fully-inside"
-
-These methods can accept a C<DateTime> list, a C<DateTime::Set>, a
-C<DateTime::Span>, or a C<DateTime::SpanSet> object as an argument.
-
-=item * previous
-
-=item * next
-
-=item * current
-
-=item * closest
-
- my $dt = $set->next( $dt );
- my $dt = $set->previous( $dt );
- my $dt = $set->current( $dt );
- my $dt = $set->closest( $dt );
-
-These methods are used to find a set member relative to a given
-datetime.
-
-The C<current()> method returns C<$dt> if $dt is an event, otherwise
-it returns the previous event.
-
-The C<closest()> method returns C<$dt> if $dt is an event, otherwise
-it returns the closest event (previous or next).
-
-All of these methods may return C<undef> if there is no matching
-datetime in the set.
-
-These methods will try to set the returned value to the same time zone
-as the argument, unless the argument has a 'floating' time zone.
-
-=item * map ( sub { ... } )
-
- # example: remove the hour:minute:second information
- $set = $set2->map(
- sub {
- return $_->truncate( to => day );
- }
- );
-
- # example: postpone or antecipate events which
- # match datetimes within another set
- $set = $set2->map(
- sub {
- return $_->add( days => 1 ) while $holidays->contains( $_ );
- }
- );
-
-This method is the "set" version of Perl "map".
-
-It evaluates a subroutine for each element of the set (locally setting
-"$_" to each datetime) and returns the set composed of the results of
-each such evaluation.
-
-Like Perl "map", each element of the set may produce zero, one, or
-more elements in the returned value.
-
-Unlike Perl "map", changing "$_" does not change the original
-set. This means that calling map in void context has no effect.
-
-The callback subroutine may be called later in the program, due to
-lazy evaluation. So don't count on subroutine side-effects. For
-example, a C<print> inside the subroutine may happen later than you
-expect.
-
-The callback return value is expected to be within the span of the
-C<previous> and the C<next> element in the original set. This is a
-limitation of the backtracking algorithm used in the C<Set::Infinite>
-library.
-
-For example: given the set C<[ 2001, 2010, 2015 ]>, the callback
-result for the value C<2010> is expected to be within the span C<[
-2001 .. 2015 ]>.
-
-=item * grep ( sub { ... } )
-
- # example: filter out any sundays
- $set = $set2->grep(
- sub {
- return ( $_->day_of_week != 7 );
- }
- );
-
-This method is the "set" version of Perl "grep".
-
-It evaluates a subroutine for each element of the set (locally setting
-"$_" to each datetime) and returns the set consisting of those
-elements for which the expression evaluated to true.
-
-Unlike Perl "grep", changing "$_" does not change the original
-set. This means that calling grep in void context has no effect.
-
-Changing "$_" does change the resulting set.
-
-The callback subroutine may be called later in the program, due to
-lazy evaluation. So don't count on subroutine side-effects. For
-example, a C<print> inside the subroutine may happen later than you
-expect.
-
-=item * iterate ( sub { ... } )
-
-I<deprecated method - please use "map" or "grep" instead.>
-
-=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@pucrs.br>
-
-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
-
projects / kivitendo-erp.git / blobdiff