plucky (3) Stone::Cursor.3pm.gz

NAME

       Stone::Cursor - Traverse tags and values of a Stone

SYNOPSIS

        use Boulder::Store;
       $store = Boulder::Store->new('./soccer_teams');

        my $stone = $store->get(28);
        $cursor = $stone->cursor;
        while (my ($key,$value) = $cursor->each) {
          print "$value: Go Bluejays!\n" if $key eq 'State' and $value eq 'Katonah';
        }

DESCRIPTION

       Boulder::Cursor is a utility class that allows you to create one or more iterators across a Stone object.
       This is used for traversing large Stone objects in order to identify or modify portions of the record.

   CLASS METHODS
       Boulder::Cursor->new($stone)
           Return a new Boulder::Cursor over the specified Stone object.  This will return an error if the
           object is not a Stone or a descendent. This method is usually not called directly, but rather
           indirectly via the Stone cursor() method:

             my $cursor = $stone->cursor;

   OBJECT METHODS
       $cursor->each()
           Iterate over the attached Stone.  Each iteration will return a two-valued list consisting of a tag
           path and a value.  The tag path is of a form that can be used with Stone::index() (in fact, a cursor
           is used internally to implement the Stone::dump() method.  When the end of the Stone is reached,
           "each()" will return an empty list, after which it will start over again from the beginning.  If you
           attempt to insert or delete from the stone while iterating over it, all attached cursors will reset
           to the beginnning.

           For example:

                   $cursor = $s->cursor;
                   while (($key,$value) = $cursor->each) {
                      print "$value: BOW WOW!\n" if $key=~/pet/;
                   }

       $cursor->reset()
           This resets the cursor back to the beginning of the associated Stone.

AUTHOR

       Lincoln D. Stein <lstein@cshl.org>.

COPYRIGHT

       Copyright 1997-1999, Cold Spring Harbor Laboratory, Cold Spring Harbor NY.  This module can be used and
       distributed on the same terms as Perl itself.

SEE ALSO

       Boulder, Stone