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 string position/offset cache is not optional. It should be.
+=head2 Unicode in Filenames
+
+chdir, chmod, chown, chroot, exec, glob, link, lstat, mkdir, open,
+opendir, qx, readdir, readlink, rename, rmdir, stat, symlink, sysopen,
+system, truncate, unlink, utime, -X. All these could potentially accept
+Unicode filenames either as input or output (and in the case of system
+and qx Unicode in general, as input or output to/from the shell).
+Whether a filesystem - an operating system pair understands Unicode in
+filenames varies.
+
+Known combinations that have some level of understanding include
+Microsoft NTFS, Apple HFS+ (In Mac OS 9 and X) and Apple UFS (in Mac
+OS X), NFS v4 is rumored to be Unicode, and of course Plan 9. How to
+create Unicode filenames, what forms of Unicode are accepted and used
+(UCS-2, UTF-16, UTF-8), what (if any) is the normalization form used,
+and so on, varies. Finding the right level of interfacing to Perl
+requires some thought. Remember that an OS does not implicate a
+filesystem.
+
+(The Windows -C command flag "wide API support" has been at least
+temporarily retired in 5.8.1, and the -C has been repurposed, see
+L<perlrun>.)
+
+=head2 Unicode in %ENV
+
+Currently the %ENV entries are always byte strings.
+
=head1 Regexps
=head2 regexp optimiser optional
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/prefixes 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
+Which is crazy given just how simple POD purports to be, and how simple HTML
+can be.
+
=head1 Misc medium sized projects
=head2 UNITCHECK
Make the peephole optimizer optional.
+=head2 You WANT *how* many
+
+Currently contexts are void, scalar and list. split has a special mechanism in
+place to pass in the number of return values wanted. It would be useful to
+have a general mechanism for this, backwards compatible and little speed hit.
+This would allow proposals such as short circuiting sort to be implemented
+as a module on CPAN.
+
=head2 lexical aliases
Allow lexical aliases (maybe via the syntax C<my \$alias = \$foo>.
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
=head2 make HTML install work
+And look at the splitting of perlfunc in chunks. It needs fixing.
+
+=head2 put patchlevel in -v
+
+Currently perl from p4/rsync ships with a patchlevel.h file that usually
+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 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
+maintenance release" or "this is a release candidate" in the terse -v output,
+and have it so that it's easy for the pumpking to remove this just as the
+release tarball is rolled up. This way the version pulled out of rsync would
+always say "I'm a development release" and it would be safe to bump the
+reported minor version as soon as a release ships, which would aid perl
+developers.
+
=head1 Incremental things
Some tasks that don't need to get done in one big hit.
Tainting would be easier to use if it didn't take documented shortcuts and allow
taint to "leak" everywhere within an expression.
+=head2 Dual life everything
+
+As part of the "dists" plan, anything that doesn't belong in the smallest perl
+distribution needs to be dual lifed. Anything else can be too.
+
=head1 Vague things
Some more nebulous ideas
=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
the dormant C<nswitch> and C<cswitch> ops in F<pp.c>; using these opcodes would
be much faster."
-** Attach/detach debugger from running program
+=head2 Attach/detach debugger from running program
The old perltodo notes "With C<gdb>, you can attach the debugger to a running
program if you pass the process ID. It would be good to do this with the Perl
debugger on a running Perl program, although I'm not sure how it would be done."
ssh and screen do this with named pipes in tmp. Maybe we can too.
+=head2 A decent benchmark
+
+perlbench seems impervious to any recent changes made to the perl core. It would
+be useful to have a reasonable general benchmarking suite that roughly
+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.
projects / p5sagit/p5-mst-13.2.git / blobdiff