# BioPerl module for Bio::SeqFeature::CollectionI
# Please direct questions and support issues to <bioperl-l@bioperl.org> 
# Cared for by Jason Stajich <jason@bioperl.org>
# Copyright Jason Stajich
# You may distribute this module under the same terms as perl itself

# POD documentation - main docs before the code

=head1 NAME

Bio::SeqFeature::CollectionI - An interface for a collection of SeqFeatureI objects. 


# get a Bio::SeqFeature::CollectionI somehow
# perhaps a Bio::SeqFeature::Collection

    use Bio::SeqFeature::Collection;
    my $collection = Bio::SeqFeature::Collection->new();

    $collection->features(-attributes => 
			  [ { 'location' => Bio::Location::Simple->new
				  (-start=> 1, -end => 300) ,
				  'overlaps' }]);


This interface describes the basic methods needed for a collection of Sequence Features.  


=head2 Mailing Lists

User feedback is an integral part of the evolution of this and other
Bioperl modules. Send your comments and suggestions preferably to
the Bioperl mailing list.  Your participation is much appreciated.

  bioperl-l@bioperl.org                  - General discussion
  http://bioperl.org/wiki/Mailing_lists  - About the mailing lists

=head2 Support 

Please direct usage questions or support issues to the mailing list:


rather than to the module maintainer directly. Many experienced and 
reponsive experts will be able look at the problem and quickly 
address it. Please include a thorough description of the problem 
with code and data examples if at all possible.

=head2 Reporting Bugs

Report bugs to the Bioperl bug tracking system to help us keep track
of the bugs and their resolution. Bug reports can be submitted via the


=head1 AUTHOR - Jason Stajich

Email jason@bioperl.org


The rest of the documentation details each of the object methods.
Internal methods are usually preceded with a _


# Let the code begin...

package Bio::SeqFeature::CollectionI;
$Bio::SeqFeature::CollectionI::VERSION = '1.7.8';
use strict;
use Carp;

use base qw(Bio::Root::RootI);

=head2 add_features

 Title   : add_features
 Usage   : $collection->add_features(\@features);
 Returns : number of features added
 Args    : arrayref of Bio::SeqFeatureI objects to index


sub add_features{

=head2 features

 Title   : features
 Usage   : my @f = $collection->features(@args);
 Returns : a list of Bio::SeqFeatureI objects
 Args    : see below
 Status  : public

This routine will retrieve features associated with this collection
object.  It can be used to return all features, or a subset based on
their type, location, or attributes.

  -types     List of feature types to return.  Argument is an array
             of Bio::Das::FeatureTypeI objects or a set of strings
             that can be converted into FeatureTypeI objects.

  -callback   A callback to invoke on each feature.  The subroutine
              will be passed to each Bio::SeqFeatureI object in turn.

  -attributes A hash reference containing attributes to match.

The -attributes argument is a hashref containing one or more attributes
to match against:

  -attributes => { Gene => 'abc-1',
                   Note => 'confirmed' }

Attribute matching is simple exact string matching, and multiple
attributes are ANDed together.  See L<Bio::DB::ConstraintsI> for a
more sophisticated take on this.

If one provides a callback, it will be invoked on each feature in
turn.  If the callback returns a false value, iteration will be
interrupted.  When a callback is provided, the method returns undef.


sub features{