Fix (or rewrite) the implementation of the C</(?{...})/> closures.
+=head1 A re-entrant regexp engine
+
+This will allow the use of a regex from inside (?{ }), (??{ }) and
+(?(?{ })|) constructs.
+
=head1 pragmata
=head2 lexical pragmas
The regexp optimiser is not optional. It should configurable to be, to allow
its performance to be measured, and its bugs to be easily demonstrated.
-=head2 common suffices/prefices in regexps (trie optimization)
-
-Currently, the user has to optimize C<foo|far> and C<foo|goo> into
-C<f(?:oo|ar)> and C<[fg]oo> by hand; this could be done automatically.
-
=head1 POD
=head2 POD -> HTML conversion still sucks
The old perltodo notes "This has been done in places, but needs a thorough
code review. Also fchdir is available in some platforms."
-=head2 foreach reverse
+=head2 Constant folding
-The old perltodo notes that we could optimise foreach to iterate in reverse.
-(instead of making a reversed copy on the stack)
+The peephole optimiser should trap errors during constant folding, and give
+up on the folding, rather than bailing out at compile time. It is quite
+possible that the unfoldable constant is in unreachable code, eg something
+akin to C<$a = 0/0 if 0;>
=head1 Tests
A test suite for the B module would be nice.
-=head2 Improve tests for Config.pm
-
-Config.pm doesn't appear to be well tested.
-
=head2 common test code for timed bailout
Write portable self destruct code for tests to stop them burning CPU in
defines one local patch, of the form "MAINT12345" or "RC1". The output of
perl -v doesn't report that a perl isn't an official release, and this
information can get lost in bugs reports. Because of this, the minor version
-isn't bumped up util RC time, to minimise the possibility of versions of perl
+isn't bumped up until RC time, to minimise the possibility of versions of perl
escaping that believe themselves to be newer than they actually are.
It would be useful to find an elegant way to have the "this is an interim
=head2 Optimize away @_
-The old perltodo notes "Look at the "reification" code in C<av.c>"
+The old perltodo notes "Look at the "reification" code in C<av.c>".
=head2 switch ops
represented what current perl programs do, and measurably reported whether
tweaks to the core improve, degrade or don't really affect performance, to
guide people attempting to optimise the guts of perl.
+
+=head2 readpipe(LIST)
+
+system() accepts a LIST syntax (and a PROGRAM LIST syntax) to avoid
+running a shell. readpipe() (the function behind qx//) could be similarly
+extended.
+
+=head2 Self ties
+
+self ties are currently illegal because they caused too many segfaults. Maybe
+the causes of these could be tracked down and self-ties on all types re-
+instated.