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authorJarkko Hietaniemi <jhi@iki.fi>2003-09-05 13:53:23 +0000
committerJarkko Hietaniemi <jhi@iki.fi>2003-09-05 13:53:23 +0000
commite77edca30a2be27033e243f6b69dee5191c27b5a (patch)
tree5ee10d63a40bcd49bd2dc57a6161688836ded147 /pod/perltie.pod
parentdf5c998e3f9219a80f4bdf527ae29d22354dd219 (diff)
downloadperl-e77edca30a2be27033e243f6b69dee5191c27b5a.tar.gz
One more known tie problem.
p4raw-id: //depot/perl@21048
Diffstat (limited to 'pod/perltie.pod')
-rw-r--r--pod/perltie.pod11
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