Author image Lincoln D. Stein
and 1 contributors


Bio::Das::Type - A sequence annotation type


  use Bio::Das;

  # contact a DAS server using the "elegans" data source
  my $das      = Bio::Das->new('' => 'elegans');

  # find out what feature types are available
  my @types       = $db->types;

  # get information on each one
  for my $t (@types) {
    my $id          = $t->id;
    my $method      = $t->method;
    my $category    = $t->category;
    my $isreference = $t->reference;
    my $label       = $t->label;
    my $method_label = $t->method_label;


The Bio::Das::Type class provides information about the type of an annotation. Each type has a category, which is a general description of the type, a unique ID, which names the type, and an optional method, which describes how the type was derived. A type may also be marked as being a landmark that can be used as a reference sequence.

Optionally, types can have human readable labels. There is one label for the type itself, and another for the type's method.


Bio::Das::Type objects are created by calling the types() method of a Bio::Das or Bio::Das::Segment object. They are also created implicity when a Bio::Das::Segment::Feature is created.

If needed, there is a simple constructor which can be called directly:

$type = Bio::Das::Type->new($id,$method,$category)

Create and return a Bio::Das::Type object with the indicated typeID, method and category.


The following methods are public. Most of them use an accessor calling style. Called without an argument, they return the current value of the attribute. Called with an argument, they change the attribute and return its previous value.

$id = $type->id([$newid])

Get or set the ID for the type;

$label = $type->label([$newlabel])

Get or set the label for the type;

$method = $type->method([$newmethod])

Get or set the method ID for the type.

$label = $type->method_label([$newlabel])

Get or set the method label for the type.

$category = $type->category([$newcategory])

Get or set the category for the type.

$reference = $type->reference([$newreference])

Get or set the value of the reference attribute. If the attribute is true, then features of this type can be used as reference sequences. However, see LIMITATIONSbelow.


Due to the requirements of the DAS spec, the reference() method will always return false for types returned by the Bio::Das->types() or Bio::Das::Segment->types() methods. As currently specified, the reference attribute is an attribute of an individual feature, and not of a generic type.


Lincoln Stein <>.

Copyright (c) 2001 Cold Spring Harbor Laboratory

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See DISCLAIMER.txt for disclaimers of warranty.


Bio::Das, Bio::Das::Segment, Bio::Das::Segment::Feature