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