return $self->{ARRAY}[$idx];
}
+If a negative array index is used to read from an array, the index
+will be translated to a positive one internally by calling FETCHSIZE
+before being passed to FETCH.
+
As you may have noticed, the name of the FETCH method (et al.) is the same
for all accesses, even though the constructors differ in names (TIESCALAR
vs TIEARRAY). While in theory you could have the same class servicing
}
return $self->{ARRAY}[$idx] = $value;
}
+
+Negative indexes are treated the same as with FETCH.
=item DESTROY this
package Remember;
use strict;
+ use warnings;
use IO::File;
sub TIESCALAR {
Now that you know what the problem is, what can you do to avoid it?
Well, the good old C<-w> flag will spot any instances where you call
untie() and there are still valid references to the tied object. If
-the second script above is run with the C<-w> flag, Perl prints this
+the second script above this near the top C<use warnings 'untie'>
+or was run with the C<-w> flag, Perl prints this
warning message:
untie attempted while 1 inner references still exist
=head1 SEE ALSO
See L<DB_File> or L<Config> for some interesting tie() implementations.
+A good starting point for many tie() implementations is with one of the
+modules L<Tie::Scalar>, L<Tie::Array>, L<Tie::Hash>, or L<Tie::Handle>.
=head1 BUGS
-Tied arrays are I<incomplete>. They are also distinctly lacking something
-for the C<$#ARRAY> access (which is hard, as it's an lvalue), as well as
-the other obvious array functions, like push(), pop(), shift(), unshift(),
-and splice().
-
You cannot easily tie a multilevel data structure (such as a hash of
hashes) to a dbm file. The first problem is that all but GDBM and
Berkeley DB have size limitations, but beyond that, you also have problems