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Summary

Bio::DB::GFF::Adaptor::dbi::iterator - iterator for Bio::DB::GFF::Adaptor::dbi

Package variables

Synopsis

For internal use only

Description

This is an internal module that is used by the Bio::DB::GFF DBI
adaptor to return an iterator across a sequence feature query. The
object has a single method, next_feature(), that returns the next
feature from the query. The method next_seq() is an alias for
next_feature().

Methods

Methods description

None available.

Methods code

sub new {

  my $class = shift;
  my ($sth,$callback) = @_;
  return bless [$sth,$callback,[]],$class;

}

sub next_feature {

  my $self = shift;
  return shift @{$self->[CACHE]} if @{$self->[CACHE]};
  my $sth = $self->[STH] or return;
  my $callback = $self->[CALLBACK];

  my $features;
  while (1) {
    if (my @row = $sth->fetchrow_array) {
      $features = $callback->(@row);
      last if $features;
    } else {
      $sth->finish;
      undef $self->[STH];
      $features = $callback->();
      last;
    }
  }
  $self->[CACHE] = $features or return;
  shift @{$self->[CACHE]};
}

1;

}

General documentation

None known yet.

Bio::DB::GFF,

Lincoln Stein <lstein@cshl.org>.
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.