diff options
author | Jarkko Hietaniemi <jhi@iki.fi> | 2003-09-05 13:53:23 +0000 |
---|---|---|
committer | Jarkko Hietaniemi <jhi@iki.fi> | 2003-09-05 13:53:23 +0000 |
commit | e77edca30a2be27033e243f6b69dee5191c27b5a (patch) | |
tree | 5ee10d63a40bcd49bd2dc57a6161688836ded147 /pod/perltie.pod | |
parent | df5c998e3f9219a80f4bdf527ae29d22354dd219 (diff) | |
download | perl-e77edca30a2be27033e243f6b69dee5191c27b5a.tar.gz |
One more known tie problem.
p4raw-id: //depot/perl@21048
Diffstat (limited to 'pod/perltie.pod')
-rw-r--r-- | pod/perltie.pod | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/pod/perltie.pod b/pod/perltie.pod index 7b8d4970ad..4befdaeee6 100644 --- a/pod/perltie.pod +++ b/pod/perltie.pod @@ -1080,6 +1080,13 @@ regardless of whether the hash is empty or hash elements). Localizing tied arrays or hashes does not work. After exiting the scope the arrays or the hashes are not restored. +Counting the number of entries in a hash via C<scalar(keys(%hash))> +or C<scalar(values(%hash)>) is inefficient since it needs to iterate +through all the entries with FIRSTKEY/NEXTKEY. + +Tied hash/array slices cause multiple FETCH/STORE pairs, there are no +tie methods for slice operations. + 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 @@ -1091,10 +1098,6 @@ source code to MLDBM. Tied filehandles are still incomplete. sysopen(), truncate(), flock(), fcntl(), stat() and -X can't currently be trapped. -Counting the number of entries in a hash via C<scalar(keys(%hash))> -or C<scalar(values(%hash)>) is inefficient since it needs to iterate -through all the entries with FIRSTKEY/NEXTKEY. - =head1 AUTHOR Tom Christiansen |