3 perltodo - Perl TO-DO List
7 This is a list of wishes for Perl. It is maintained by Nathan
8 Torkington for the Perl porters. Send updates to
9 I<perl5-porters@perl.org>. If you want to work on any of these
10 projects, be sure to check the perl5-porters archives for past ideas,
11 flames, and propaganda. This will save you time and also prevent you
12 from implementing something that Larry has already vetoed. One set
13 of archives may be found at:
15 http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/
20 =head2 Mailing list archives
22 Chaim suggests contacting egroup and asking them to archive the other
23 perl.org mailing lists. Probably not advocacy, but definitely
26 =head2 Bug tracking system
28 Richard Foley I<richard@perl.org> is writing one. We looked at
29 several, like gnats and the Debian system, but at the time we
30 investigated them, none met our needs. Since then, Jitterbug has
31 matured, and may be worth reinvestigation.
33 The system we've developed will eventually be recipient of perlbug
34 mail. New bugs are entered into a mysql database, and sent on to
35 perl5-porters with the subject line rewritten to include a "ticket
36 number" (unique ID for the new bug). If the incoming message already
37 had a ticket number in the subject line, then the message is logged
38 against that bug. There is a separate email interface (not forwarding
39 to p5p) that permits porters to claim, categorize, and close tickets.
41 The next desire is a web interface. It is hoped that code can be
42 reused between the mail and the web interfaces.
44 The current delay in implementation is caused by perl.org lockups.
45 One suspect is the mail handling system, possibly going into loops.
47 We're probably going to need a bugmaster, someone who will look at
48 every new "bug" and kill those that we already know about, those
49 that are not bugs at all, etc.
51 =head2 Regression Tests
53 The test suite for Perl serves two needs: ensuring features work, and
54 ensuring old bugs have not been reintroduced. Both need work.
56 Brent LaVelle (lavelle@metronet.com) has stepped forward to work on
57 performance tests and improving the size of the test suite.
63 Do the tests that come with Perl exercise every line (or every block,
64 or ...) of the Perl interpreter, and if not then how can we make them
69 No bug fixes should be made without a corresponding testsuite addition.
70 This needs a dedicated enforcer, as the current pumpking is either too
71 lazy or too stupid or both and lets enforcement wander all over the
76 Tests that fail need to be of a form that can be readily mailed
77 to perlbug and diagnosed with minimal back-and-forth's to determine
78 which test failed, due to what cause, etc.
82 We need regression/sanity tests for suidperl
84 =item The 25% slowdown from perl4 to perl5
86 This value may or may not be accurate, but it certainly is
87 eye-catching. For some things perl5 is faster than perl4, but often
88 the reliability and extensability have come at a cost of speed. The
89 benchmark suite that Gisle released earlier has been hailed as both a
90 fantastic solution and as a source of entirely meaningless figures.
91 Do we need to test "real applications"? Can you do so? Anyone have
92 machines to dedicate to the task? Identify the things that have grown
93 slower, and see if there's a way to make them faster.
99 Andy Dougherty maintain(ed|s) a list of "todo" items for the configure
100 that comes with Perl. See Porting/pumpkin.pod in the latest
105 Have "make install" give you the option to install HTML as well. This
106 would be part of Configure. Andy Wardley (certified Perl studmuffin)
107 will look into the current problems of HTML installation--is
108 'installhtml' preventing this from happening cleanly, or is pod2html
109 the problem? If the latter, Brad Appleton's pod work may fix the
116 Declare global variables (lexically or otherwise).
120 Verify complete 64 bit support so that the value of sysseek, or C<-s>, or
121 stat(), or tell can fit into a perl number without losing precision.
122 Work with the perl-64bit mailing list on perl.org.
128 =item Named prototypes
130 Add proper named prototypes that actually work usefully.
132 =item Indirect objects
134 Fix prototype bug that forgets indirect objects.
138 Prototypes for method calls.
142 Return context prototype declarations.
146 lexically-scoped subs, e.g. my sub
150 =head2 Built-in globbing
152 Currently the C<E<lt>*.cE<gt>> syntax calls the c shell. This causes
153 problems on sites without csh, systems where fork() is expensive, and
154 setuid environments. Decide between Glob::BSD and File::KGlob, move
155 it into the core, and make Perl use it for globbing. Ben Holzman and
156 Tye McQueen have claimed the pumpkin for this.
158 =head1 Perl Internals
162 C<magic_setisa> should be made to update %FIELDS [???]
164 =head2 Garbage Collection
166 There was talk of a mark-and-sweep garbage collector at TPC2, but the
167 (to users) unpredictable nature of its behaviour put some off.
168 Sarathy, I believe, did the work. Here's what he has to say:
170 Yeah, I hope to implement it someday too. The points that were
171 raised in TPC2 were all to do with calling DESTROY() methods, but
172 I think we can accomodate that by extending bless() to stash
173 extra information for objects so we track their lifetime accurately
174 for those that want their DESTROY() to be predictable (this will be
175 a speed hit, naturally, and will therefore be optional, naturally. :)
177 [N.B. Don't even ask me about this now! When I have the time to
178 write a cogent summary, I'll post it.]
180 =head2 Reliable signals
182 Sarathy and Dan Sugalski are working on this. Chip posted a patch
183 earlier, but it was not accepted into 5.005. The issue is tricky,
184 because it has the potential to greatly slow down the core.
186 There are at least three things to consider:
190 =item Alternate runops() for signal despatch
192 Sarathy and Dan are discussed this on perl5-porters.
194 =item Figure out how to die() in delayed sighandler
196 =item Add tests for Thread::Signal
198 =item Automatic tests against CPAN
200 Is there some way to automatically build all/most of CPAN with
201 the new Perl and check that the modules there pass all the tests?
205 =head2 Interpolated regex performance bugs
209 foreach $pat (@patterns) {
215 The qr// syntax added in 5.005 has solved this problem, but
216 it needs more thorough documentation.
218 =head2 Memory leaks from failed eval/regcomp
220 The only known memory leaks in Perl are in failed code or regexp
221 compilation. Fix this. Hugo Van Der Sanden will attempt this but
222 won't have tuits until January 1999.
224 =head2 Make XS easier to use
226 There was interest in SWIG from porters, but nothing has happened
229 =head2 Make embedded Perl easier to use
231 This is probably difficult for the same reasons that "XS For Dummies"
234 =head2 Namespace cleanup
236 CPP-space: restrict CPP symbols exported from headers
237 header-space: move into CORE/perl/
238 API-space: begin list of things that constitute public api
239 env-space: Configure should use PERL_CONFIG instead of CONFIG etc.
243 Complete work on safe recursive interpreters C<Perl-E<gt>new()>.
244 Sarathy says that a reference implementation exists.
248 Chris Nandor and Matthias Neeracher are working on better integrating
249 MacPerl into the Perl distribution.
253 There's a lot of documentation that comes with Perl. The quantity of
254 documentation makes it difficult for users to know which section of
255 which manpage to read in order to solve their problem. Tom
256 Christiansen has done much of the documentation work in the past.
258 =head2 A clear division into tutorial and reference
260 Some manpages (e.g., perltoot and perlreftut) clearly set out to
261 educate the reader about a subject. Other manpages (e.g., perlsub)
262 are references for which there is no tutorial, or are references with
263 a slight tutorial bent. If things are either tutorial or reference,
264 then the reader knows which manpage to read to learn about a subject,
265 and which manpage to read to learn all about an aspect of that
266 subject. Part of the solution to this is:
268 =head2 Remove the artificial distinction between operators and functions
270 History shows us that users, and often porters, aren't clear on the
271 operator-function distinction. The present split in reference
272 material between perlfunc and perlop hinders user navigation. Given
273 that perlfunc is by far the larger of the two, move operator reference
276 =head2 More tutorials
278 More documents of a tutorial nature could help. Here are some
283 =item Regular expressions
285 Robin Berjon (r.berjon@ltconsulting.net) has volunteered.
289 Mark-Jason Dominus (mjd@plover.com) has an outline for perliotut.
293 This is badly needed. There has been some discussion on the
294 subject on perl5-porters.
298 Ronald Kimball (rjk@linguist.dartmouth.edu) has volunteered.
302 =head2 Include a search tool
304 perldoc should be able to 'grep' fulltext indices of installed POD
305 files. This would let people say:
307 perldoc -find printing numbers with commas
309 and get back the perlfaq entry on 'commify'.
311 This solution, however, requires documentation to contain the keywords
312 the user is searching for. Even when the users know what they're
313 looking for, often they can't spell it.
315 =head2 Include a locate tool
317 perldoc should be able to help people find the manpages on a
318 particular high-level subject:
322 would tell them manpages, web pages, and books with material on web
323 programming. Similarly C<perldoc -find databases>, C<perldoc -find
324 references> and so on.
326 We need something in the vicinity of:
328 % perl -help random stuff
329 No documentation for perl function `random stuff' found
330 The following entry in perlfunc.pod matches /random/a:
335 Returns a random fractional number greater than or equal to C<0> and less
336 than the value of EXPR. (EXPR should be positive.) If EXPR is
337 omitted, the value C<1> is used. Automatically calls C<srand()> unless
338 C<srand()> has already been called. See also C<srand()>.
340 (Note: If your rand function consistently returns numbers that are too
341 large or too small, then your version of Perl was probably compiled
342 with the wrong number of RANDBITS.)
343 The following pod pages seem to have /stuff/a:
344 perlfunc.pod (7 hits)
345 perlfaq7.pod (6 hits)
348 perlfaq8.pod (2 hits)
350 perl5004delta.pod (1 hit)
351 perl5005delta.pod (1 hit)
353 perldelta.pod (1 hit)
360 Proceed to open perlfunc.pod? [y] n
361 Do you want to speak perl interactively? [y] n
362 Should I dial 911? [y] n
363 Do you need psychiatric help? [y] y
364 <PELIZA> Hi, what bothers you today?
365 A Python programmer in the next cubby is driving me nuts!
366 <PELIZA> Hmm, thats fixable. Just [rest censored]
368 =head2 Separate function manpages by default
370 Perl should install 'manpages' for every function/operator into the
371 3pl or 3p manual section. By default. The splitman program in the
372 Perl source distribution does the work of turning big perlfunc into
375 =head2 Users can't find the manpages
377 Make C<perldoc> tell users what they need to add to their .login or
378 .cshrc to set their MANPATH correctly.
380 =head2 Install ALL Documentation
382 Make the standard documentation kit include the VMS, OS/2, Win32,
383 Threads, etc information. installperl and pod/Makefile should know
384 enough to copy README.foo to perlfoo.pod before building everything,
387 =head2 Outstanding issues to be documented
389 Tom has a list of 5.005_5* features or changes that require
392 Create one document that coherently explains the delta between the
393 last camel release and the current release. perldelta was supposed
394 to be that, but no longer. The things in perldelta never seemed to
395 get placed in the right places in the real manpages, either. This
398 =head2 Adapt www.linuxhq.com for Perl
400 This should help glorify documentation and get more people involved in
403 =head2 Replace man with a perl program
405 Can we reimplement man in Perl? Tom has a start. I believe some of
406 the Linux systems distribute a manalike. Alternatively, build on
407 perldoc to remove the unfeatures like "is slow" and "has no apropos".
409 =head2 Unicode tutorial
411 We could use more work on helping people understand Perl's new
412 Unicode support that Larry has created.
416 =head2 Update the POSIX extension to conform with the POSIX 1003.1 Edition 2
418 The current state of the POSIX extension is as of Edition 1, 1991,
419 whereas the Edition 2 came out in 1996. ISO/IEC 9945:1-1996(E),
420 ANSI/IEEE Std 1003.1, 1996 Edition. ISBN 1-55937-573-6. The updates
421 were legion: threads, IPC, and real time extensions.
423 =head2 Module versions
425 Automate the checking of versions in the standard distribution so
426 it's easy for a pumpking to check whether CPAN has a newer version
427 that we should be including?
431 Which modules should be added to the standard distribution? This ties
432 in with the SDK discussed on the perl-sdk list at perl.org.
436 Make the profiler (Devel::DProf) part of the standard release, and
445 Implement array using vec(). Nathan Torkington has working code to
450 Implement array using substr()
454 Implement array using a file
458 Defines shift et al in terms of splice method
462 =head2 Procedural options
464 Support procedural interfaces for the common cases of Perl's
465 gratuitously OOO modules. Tom objects to "use IO::File" reading many
466 thousands of lines of code.
470 Write a module for transparent, portable remote procedure calls. (Not
471 core). This touches on the CORBA and ILU work.
473 =head2 y2k localtime/gmtime
475 Write a module, Y2k::Catch, which overloads localtime and gmtime's
476 returned year value and catches "bad" attempts to use it.
478 =head2 Export File::Find variables
480 Make File::Find export C<$name> etc manually, at least if asked to.
484 Finish a proper Ioctl module.
486 =head2 Debugger attach/detach
488 Permit a user to debug an already-running program.
490 =head2 Regular Expression debugger
492 Create a visual profiler/debugger tool that stepped you through the
493 execution of a regular expression point by point. Ilya has a module
494 to color-code and display regular expression parses and executions.
495 There's something at http://tkworld.org/ that might be a good start,
496 it's a Tk/Tcl RE wizard, that builds regexen of many flavours.
498 =head2 Alternative RE Syntax
500 Make an alternative regular expression syntax that is accessed through
501 a module. For instance,
504 $re = start_of_line()
505 ->literal("1998/10/08")
506 ->optional( whitespace() )
508 ->remember( many( or( "-", digit() ) ) );
511 print "time is $1\n";
514 Newbies to regular expressions typically only use a subset of the full
515 language. Perhaps you wouldn't have to implement the full feature set.
517 =head2 Bundled modules
519 Nicholas Clark (nick@flirble.org) had a patch for storing modules in
520 zipped format. This needs exploring and concluding.
524 Adopt IO::Tty, make it as portable as Don Libes' "expect" (can we link
525 against expect code?), and perfect a Perl version of expect. IO::Tty
526 and expect could then be distributed as part of the core distribution,
527 replacing Comm.pl and other hacks.
531 A simple-to-use interface to native graphical abilities would
532 be welcomed. Oh, Perl's access Tk is nice enough, and reasonably
533 portable, but it's not particularly as fast as one would like.
534 Simple access to the mouse's cut buffer or mouse-presses shouldn't
535 required loading a few terabytes of Tk code.
537 =head2 Update semibroken auxiliary tools; h2ph, a2p, etc.
539 Kurt Starsinic is working on h2ph. mjd has fixed bugs in a2p in the
540 past. a2p apparently doesn't work on nawk and gawk extensions.
541 Graham Barr has an Include module that does h2ph work at runtime.
543 =head2 POD Converters
545 Brad's PodParser code needs to become part of the core, and the Pod::*
546 and pod2* programs rewritten to use this standard parser. Currently
547 the converters take different options, some behave in different
548 fashions, and some are more picky than others in terms of the POD
553 A short-term fix: pod2html generates absolute HTML links. Make it
554 generate relative links.
558 Something like lint for Pod would be good. Something that catches
559 common errors as well as gross ones. Brad Appleton is putting
560 together something as part of his PodParser work.
566 Design a webperl environment that's as tightly integrated and as
567 easy-to-use as Perl's current command-line environment.
571 More work on a safe and secure execution environment for mobile
572 agents would be neat; the Safe.pm module is a start, but there's a
573 still a lot to be done in that area. Adopt Penguin?
575 =head2 POSIX on non-POSIX
577 Standard programming constructs for non-POSIX systems would help a
578 lot of programmers stuck on primitive, legacy systems. For example,
579 Microsoft still hasn't made a usable POSIX interface on their clunky
580 systems, which means that standard operations such as alarm() and
581 fork(), both critical for sophisticated client-server programming,
582 must both be kludged around.
584 I'm unsure whether Tom means to emulate alarm( )and fork(), or merely
585 to provide a document like perlport.pod to say which features are
586 portable and which are not.
588 =head2 Portable installations
590 Figure out a portable semi-gelled installation, that is, one without
591 full paths. Larry has said that he's thinking about this. Ilya
592 pointed out that perllib_mangle() is good for this.
596 =head2 Get PERL_OBJECT building under gcc
598 B<Part done>, according to Sarathy. It builds under egcs on win32,
599 but doesn't run for occult reasons. If anyone knows the right
600 breed of chicken to sacrifice, please speak up.
602 =head2 Rename new headers to be consistent with the rest
604 =head2 Sort out the spawnvp() mess
606 =head2 Work out DLL versioning
608 =head2 Get PERL_OBJECT building on non-win32
612 =head1 Would be nice to have
616 =item C<pack "(stuff)*">
618 =item Contiguous bitfields in pack/unpack
622 =item Bundled perl preprocessor
624 =item Use posix calls internally where possible
628 =item -i rename file only when successfully changed
630 =item All ARGV input should act like <>
632 =item report HANDLE [formats].
634 =item support in perlmain to rerun debugger
636 =item lvalue functions
638 Tuomas Lukka, on behalf of the PDL project, greatly desires this and
639 Ilya has a patch for it (probably against an older version of Perl).
640 Tuomas points out that what PDL really wants is lvalue I<methods>,
645 =head1 Possible pragmas
649 (use less memory, CPU)
653 =head2 constant function cache
655 =head2 foreach(reverse...)
657 =head2 Cache eval tree
659 Unless lexical outer scope used (mark in &compiling?).
663 =head2 Shrink opcode tables
665 Via multiple implementations selected in peep.
667 =head2 Cache hash value
669 Not a win, according to Guido.
671 =head2 Optimize away @_ where possible
673 =head2 Optimize sort by { $a <=> $b }
675 Greg Bacon added several more sort optimizations. These have
676 made it into 5.005_55, thanks to Hans Mulder.
678 =head2 Rewrite regexp parser for better integrated optimization
680 The regexp parser was rewritten for 5.005. Ilya's the regexp guru.
682 =head1 Vague possibilities
686 =item ref function in list context
688 This seems impossible to do without substantially breaking code.
690 =item make tr/// return histogram in list context?
692 =item Loop control on do{} et al
694 =item Explicit switch statements
696 Nobody has yet managed to come up with a switch syntax that would
697 allow for mixed hash, constant, regexp checks. Submit implementation
700 =item compile to real threaded code
702 =item structured types
704 =item Modifiable $1 et al
706 The intent is for this to be a means of editing the matched portions of
711 =head1 To Do Or Not To Do
713 These are things that have been discussed in the past and roundly
714 criticized for being of questionable value.
716 =head2 Making my() work on "package" variables
718 Being able to say my($Foo::Bar), something that sounds ludicrous and
719 the 5.6 pumpking has mocked.
721 =head2 "or" testing defined not truth
723 We tell people that C<||> can be used to give a default value to a
726 $children = shift || 5; # default is 5 children
728 which is almost (but not):
731 $children = 5 unless $children;
733 but if the first argument was given and is "0", then it will be
734 considered false by C<||> and C<5> used instead. Really we want
735 an C<||>-like operator that behaves like:
738 $children = 5 unless defined $children;
740 Namely, a C<||> that tests defined-ness rather than truth. One was
741 discussed, and a patch submitted, but the objections were many. While
742 there were objections, many still feel the need. At least it was
743 decided that C<??> is the best name for the operator.
745 =head2 "dynamic" lexicals
752 Localizing, as Tim Bunce points out, is a separate concept from
753 whether the variable is global or lexical. Chip Salzenberg had
754 an implementation once, but Larry thought it had potential to
757 =head2 "class"-based, rather than package-based "lexicals"
759 This is like what the Alias module provides, but the variables would
760 be lexicals reserved by perl at compile-time, which really are indices
761 pointing into the pseudo-hash object visible inside every method so
768 Which of the standard modules are thread-safe? Which CPAN modules?
769 How easy is it to fix those non-safe modules?
773 Threading is still experimental. Every reproducible bug identifies
774 something else for us to fix. Find and submit more of these problems.
780 Consistent semantics for exit/die in threads.
782 =head2 External threads
784 Better support for externally created threads.
790 Spot-check globals like statcache and global GVs for thread-safety.
791 "B<Part done>", says Sarathy.
793 =head2 Per-thread GVs
795 According to Sarathy, this would make @_ be the same in threaded
796 and non-threaded, as well as helping solve problems like filehandles
797 (the same filehandle currently cannot be used in two threads).
803 The compiler's back-end code-generators for creating bytecode or
804 compilable C code could use optimization work.
808 Figure out how and where byteperl will be built for the various
811 =head2 Precompiled modules
813 Save byte-compiled modules on disk.
817 Auto-produce executable.
819 =head2 Typed lexicals
821 Typed lexicals should affect B::CC::load_pad.
825 Workarounds to help Win32 dynamic loading.
829 END blocks need saving in compiled output, now that CHECK blocks
838 Fix comppadlist (names in comppad_name can have fake SvCUR
839 from where newASSIGNOP steals the field).
841 =head2 Cached compilation
843 Can we install modules as bytecode?
845 =head1 Recently Finished Tasks
847 =head2 Figure a way out of $^(capital letter)
849 Figure out a clean way to extend $^(capital letter) beyond
850 the 26 alphabets. (${^WORD} maybe?)
852 Mark-Jason Dominus sent a patch which went into 5.005_56.
856 Make filenames in the distribution and in the standard module set
857 be 8.3 friendly where feasible. Good luck changing the standard
858 modules, though. B<Done>.
860 =head2 Proper tied array support
862 This was B<done> in 5.005 by Nick Ing-Simmons.
866 Perl should be more generous in accepting foreign line terminations.
867 Mostly B<done> in 5.005.
869 =head2 Namespace cleanup
871 symbol-space: "pl_" prefix for all global vars
872 "Perl_" prefix for all functions
874 CPP-space: stop malloc()/free() pollution unless asked
878 Given a piece of Perl code, say what it does. B::Deparse is doing
883 Rename and alter ISA.pm. B<Done>. It is now base.pm.
885 =head2 Automate maintenance of most PERL_OBJECT code
887 B<Done>, says Sarathy.
891 Added in 5.004_70. B<Done>
897 =head2 reference to compiled regexp
899 B<done> This is the qr// support in 5.005.
901 =head2 eval qw() at compile time
903 qw() is presently compiled as a call to split. This means the split
904 happens at runtime. Change this so qw() is compiled as a real list
905 assignment. This also avoids surprises like:
907 $a = () = qw(What will $a hold?);
909 B<Done>. Tom Hughes submitted a patch that went into 5.005_55.
913 B<Done>. This is the Fatal.pm module, so any builtin that that does
914 not return success automatically die()s. If you're feeling brave, tie
915 this in with the unified exceptions scheme.
917 =head2 Status variable
919 $^C to track compiler/checker status. B<Done> in 5.005_54.