NAME

DateTime::SpanSet - set of DateTime spans

SYNOPSIS

    $spanset = DateTime::SpanSet->from_spans( spans => [ $dt_span, $dt_span ] );

    $set = $spanset->union( $set2 );         # like "OR", "insert", "both"
    $set = $spanset->complement( $set2 );    # like "delete", "remove"
    $set = $spanset->intersection( $set2 );  # like "AND", "while"
    $set = $spanset->complement;             # like "NOT", "negate", "invert"

    if ( $spanset->intersects( $set2 ) ) { ...  # like "touches", "interferes"
    if ( $spanset->contains( $set2 ) ) { ...    # like "is-fully-inside"

    # data extraction 
    $date = $spanset->min;           # first date of the set
    $date = $spanset->max;           # last date of the set

    $iter = $spanset->iterator;
    while ( $dt = $iter->next ) {
        # $dt is a DateTime::Span
        print $dt->start->ymd;   # first date of span
        print $dt->end->ymd;     # last date of span
    };

DESCRIPTION

DateTime::SpanSet is a class that represents sets of datetime spans. An example would be a recurring meeting that occurs from 13:00-15:00 every Friday.

METHODS

• from_spans

  Creates a new span set from one or more DateTime::Span objects.

     $spanset = DateTime::SpanSet->from_spans( spans => [ $dt_span ] );

• from_set_and_duration

  Creates a new span set from one or more DateTime::Set objects and a duration.

  The duration can be a DateTime::Duration object, or the parameters to create a new DateTime::Duration object, such as "days", "months", etc.

     $spanset =
         DateTime::SpanSet->from_set_and_duration
             ( set => $dt_set, days => 1 );

• from_sets

  Creates a new span set from two DateTime::Set objects.

  One set defines the starting dates, and the other defines the end dates.

     $spanset =
         DateTime::SpanSet->from_sets
             ( start_set => $dt_set1, end_set => $dt_set2 );

  The spans have the starting date closed, and the end date open, like in [$dt1, $dt2).

  If an end date comes without a starting date before it, then it defines a span like (-inf, $dt).

  If a starting date comes without an end date after it, then it defines a span like [$dt, inf).

• empty_set

  Creates a new empty set.

• clone

  This object method returns a replica of the given object.

• set_time_zone( $tz )

  This method accepts either a time zone object or a string that can be passed as the "name" parameter to DateTime::TimeZone->new(). If the new time zone's offset is different from the old time zone, then the 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 UTC time is adjusted in order to leave the local time untouched.

• min / max

  First or last dates in the set. These methods may return undef if the set is empty. It is also possible that these methods may return a scalar containing infinity or negative infinity.

• duration

  The total size of the set, as a DateTime::Duration object, or as a scalar containing infinity.

  Also available as size().

• span

  The total span of the set, as a DateTime::Span object.

• union / intersection / complement

  Set operations may be performed not only with DateTime::SpanSet objects, but also with DateTime, DateTime::Set and DateTime::Span objects. These set operations always return a DateTime::SpanSet object.

      $set = $spanset->union( $set2 );         # like "OR", "insert", "both"
      $set = $spanset->complement( $set2 );    # like "delete", "remove"
      $set = $spanset->intersection( $set2 );  # like "AND", "while"
      $set = $spanset->complement;             # like "NOT", "negate", "invert"

• intersects / contains

  These set functions return a boolean value.

      if ( $spanset->intersects( $set2 ) ) { ...  # like "touches", "interferes"
      if ( $spanset->contains( $dt ) ) { ...    # like "is-fully-inside"

  These methods can accept a DateTime, DateTime::Set, DateTime::Span, or DateTime::SpanSet object as an argument.

• iterator / next

  This method can be used to iterate over the spans in a set.

      $iter = $spanset->iterator;
      while ( $dt = $iter->next ) {
          # $dt is a DateTime::Span
          print $dt->min->ymd;   # first date of span
          print $dt->max->ymd;   # last date of span
      }

  The boundaries of the iterator can be limited by passing it a span parameter. This should be a 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 DateTime::Span class's constructors, and an object will be created for you.

  Obviously, if the span you specify does 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 next() method will return undef when there are no more datetimes in the iterator.

SUPPORT

Support is offered through the datetime@perl.org mailing list.

Please report bugs using rt.cpan.org

AUTHOR

Flavio Soibelmann Glock <fglock@pucrs.br>

The API was developed together with Dave Rolsky and the DateTime Community.

COPYRIGHT

Copyright (c) 2003 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.

SEE ALSO

Set::Infinite

For details on the Perl DateTime Suite project please see http://datetime.perl.org.