Unknown discipline ':utf8' w/ maint perl w/o perlio

[p5sagit/p5-mst-13.2.git] / pod / perltie.pod

diff --git a/pod/perltie.pod b/pod/perltie.pod
index 3665f04..4befdae 100644 (file)
--- a/pod/perltie.pod
+++ b/pod/perltie.pod
@@ -794,9 +794,16 @@ READ, and possibly CLOSE, UNTIE and DESTROY.  The class can also provide: BINMOD
 OPEN, EOF, FILENO, SEEK, TELL - if the corresponding perl operators are
 used on the handle.
 
-It is especially useful when perl is embedded in some other program,
-where output to STDOUT and STDERR may have to be redirected in some
-special way. See nvi and the Apache module for examples.
+When STDERR is tied, its PRINT method will be called to issue warnings
+and error messages.  This feature is temporarily disabled during the call, 
+which means you can use C<warn()> inside PRINT without starting a recursive
+loop.  And just like C<__WARN__> and C<__DIE__> handlers, STDERR's PRINT
+method may be called to report parser errors, so the caveats mentioned under 
+L<perlvar/%SIG> apply.
+
+All of this is especially useful when perl is embedded in some other 
+program, where output to STDOUT and STDERR may have to be redirected 
+in some special way.  See nvi and the Apache module for examples.
 
 In our example we're going to create a shouting handle.
 
@@ -1065,6 +1072,21 @@ modules L<Tie::Scalar>, L<Tie::Array>, L<Tie::Hash>, or L<Tie::Handle>.
 
 =head1 BUGS
 
+The bucket usage information provided by C<scalar(%hash)> is not
+available.  What this means is that using %tied_hash in boolean
+context doesn't work right (currently this always tests false,
+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
@@ -1076,14 +1098,6 @@ source code to MLDBM.
 Tied filehandles are still incomplete.  sysopen(), truncate(),
 flock(), fcntl(), stat() and -X can't currently be trapped.
 
-The bucket usage information provided by C<scalar(%hash)> is not
-available.  If C<%hash> is tied, this will currently result in a
-fatal error.
-
-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