3 perltodo - Perl TO-DO List
7 This is a list of wishes for Perl. Send updates to
8 I<perl5-porters@perl.org>. If you want to work on any of these
9 projects, be sure to check the perl5-porters archives for past ideas,
10 flames, and propaganda. This will save you time and also prevent you
11 from implementing something that Larry has already vetoed. One set
12 of archives may be found at:
14 http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/
16 =head1 To do during 5.6.x
18 =head2 Support for I/O disciplines
20 C<perlio> provides this, but the interface could be a lot more
23 =head2 Autoload bytes.pm
25 When the lexer sees, for instance, C<bytes::length>, it should
26 automatically load the C<bytes> pragma.
28 =head2 Make "\u{XXXX}" et al work
30 Danger, Will Robinson! Discussing the semantics of C<"\x{F00}">,
31 C<"\xF00"> and C<"\U{F00}"> on P5P I<will> lead to a long and boring
34 =head2 Create a char *sv_pvprintify(sv, STRLEN *lenp, UV flags)
36 For displaying PVs with control characters, embedded nulls, and Unicode.
37 This would be useful for printing warnings, or data and regex dumping,
38 not_a_number(), and so on.
40 Requirements: should handle both byte and UTF-8 strings. isPRINT()
41 characters printed as-is, character less than 256 as \xHH, Unicode
42 characters as \x{HHH}. Don't assume ASCII-like, either, get somebody
43 on EBCDIC to test the output.
45 Possible options, controlled by the flags:
46 - whitespace (other than ' ' of isPRINT()) printed as-is
47 - use isPRINT_LC() instead of isPRINT()
48 - print control characters like this: "\cA"
49 - print control characters like this: "^A"
50 - non-PRINTables printed as '.' instead of \xHH
51 - use \OOO instead of \xHH
52 - use the C/Perl-metacharacters like \n, \t
53 - have a maximum length for the produced string (read it from *lenp)
54 - append a "..." to the produced string if the maximum length is exceeded
55 - really fancy: print unicode characters as \N{...}
57 NOTE: pv_display(), pv_uni_display(), sv_uni_display() are already
58 doing something like the above.
60 =head2 Overloadable regex assertions
62 This may or may not be possible with the current regular expression
63 engine. The idea is that, for instance, C<\b> needs to be
64 algorithmically computed if you're dealing with Thai text. Hence, the
65 B<\b> assertion wants to be overloaded by a function.
73 Allow for long form of the General Category Properties, e.g
74 C<\p{IsOpenPunctuation}>, not just the abbreviated form, e.g.
79 Allow for the metaproperties: C<XID Start>, C<XID Continue>,
80 C<NF*_NO>, C<NF*_MAYBE> (require the DerivedCoreProperties and
81 DerviceNormalizationProperties files).
83 There are also multiple value properties still unimplemented:
84 C<Numeric Type>, C<East Asian Width>.
88 Case Mappings? http://www.unicode.org/unicode/reports/tr21/
90 Mostly implemented (all of 1:1, 1:N, N:1), only the "final sigma"
91 and locale-specific rules of SpecCase are not implemented.
95 UTF-8 identifier names should probably be canonicalized: NFC?
99 UTF-8 in package names and sub names? The first is problematic
100 because of the mapping to pathnames, ditto for the second one if
101 one does autosplitting, for example. Some of this works already
102 in 5.8.0, but essentially it is unsupported. Constructs to consider,
106 package UnicodePackage;
107 sub new { bless {}, shift };
108 sub UnicodeMethod1 { ... $_[0]->UnicodeMethod2(...) ... }
109 sub UnicodeMethod2 { ... } # in here caller(0) should contain Unicode
112 my $x = UnicodePackage->new;
113 print ref $x, "\n"; # should be Unicode
114 $x->UnicodeMethod1(...);
115 my $y = UnicodeMethod3 UnicodePackage ...;
117 In the above all I<UnicodeXxx> contain (identifier-worthy) characters
118 beyond the code point 255, for example 256. Wherever package/class or
119 subroutine names can be returned needs to be checked for Unicodeness.
123 See L<perlunicode/UNICODE REGULAR EXPRESSION SUPPORT LEVEL> for what's
124 there and what's missing. Almost all of Levels 2 and 3 is missing,
125 and as of 5.8.0 not even all of Level 1 is there.
126 They have some tricks Perl doesn't yet implement, such as character
129 http://www.unicode.org/unicode/reports/tr18/
131 =head2 Work out exit/die semantics for threads
133 There are some suggestions to use for example something like this:
134 default to "(thread exiting first will) wait for the other threads
135 until up to 60 seconds". Other possibilities:
137 use threads wait => 0;
141 use threads wait_for => 10;
143 Wait up to 10 seconds.
145 use threads wait_for => -1;
149 http://archive.develooper.com/perl5-porters@perl.org/msg79618.html
151 =head2 Better support for nonpreemptive threading systems like GNU pth
153 To better support nonpreemptive threading systems, perhaps some of the
154 blocking functions internally in Perl should do a yield() before a
155 blocking call. (Now certain threads tests ({basic,list,thread.t})
156 simply do a yield() before they sleep() to give nonpreemptive thread
157 implementations a chance).
159 In some cases, like the GNU pth, which has replacement functions that
160 are nonblocking (pth_select instead of select), maybe Perl should be
161 using them instead when built for threading.
163 =head2 Typed lexicals for compiler
165 =head2 Compiler workarounds for Win32
167 =head2 AUTOLOADing in the compiler
169 =head2 Fixing comppadlist when compiling
171 =head2 Cleaning up exported namespace
173 =head2 Complete signal handling
175 Add C<PERL_ASYNC_CHECK> to opcodes which loop; replace C<sigsetjmp> with
176 C<sigjmp>; check C<wait> for signal safety.
178 =head2 Out-of-source builds
180 This was done for 5.6.0, but needs reworking for 5.7.x
182 =head2 POSIX realtime support
184 POSIX 1003.1 1996 Edition support--realtime stuff: POSIX semaphores,
185 message queues, shared memory, realtime clocks, timers, signals (the
186 metaconfig units mostly already exist for these)
188 =head2 UNIX98 support
190 Reader-writer locks, realtime/asynchronous IO
194 There are non-core modules, such as C<Socket6>, but these will need
195 integrating when IPv6 actually starts to really happen. See RFC 2292
198 =head2 Long double conversion
200 Floating point formatting is still causing some weird test failures.
204 Locales and Unicode interact with each other in unpleasant ways.
205 One possible solution would be to adopt/support ICU:
207 http://oss.software.ibm.com/icu/index.html
209 =head2 Arithmetic on non-Arabic numerals
211 C<[1234567890]> aren't the only numerals any more.
213 =head2 POSIX Unicode character classes
215 (C<[=a=]> for equivalence classes, C<[.ch.]> for collation.)
216 These are dependent on Unicode normalization and collation.
218 =head2 Factoring out common suffices/prefices in regexps (trie optimization)
220 Currently, the user has to optimize C<foo|far> and C<foo|goo> into
221 C<f(?:oo|ar)> and C<[fg]oo> by hand; this could be done automatically.
223 =head2 Security audit shipped utilities
225 All the code we ship with Perl needs to be sensible about temporary file
226 handling, locking, input validation, and so on.
228 =head2 Sort out the uid-setting mess
230 Currently there are several problems with the setting of uids ($<, $>
231 for the real and effective uids). Firstly, what exactly setuid() call
232 gets invoked in which platform is simply a big mess that needs to be
233 untangled. Secondly, the effects are apparently not standard across
234 platforms, (if you first set $< and then $>, or vice versa, being
235 uid == euid == zero, or just euid == zero, or as a normal user, what are
236 the results?). The test suite not (usually) being run as root means
237 that these things do not get much testing. Thirdly, there's quite
238 often a third uid called saved uid, and Perl has no knowledge of that
239 feature in any way. (If one has the saved uid of zero, one can get
240 back any real and effective uids.) As an example, to change also the
241 saved uid, one needs to set the real and effective uids B<twice>-- in
242 most systems, that is: in HP-UX that doesn't seem to work.
244 =head2 Custom opcodes
246 Have a way to introduce user-defined opcodes without the subroutine call
247 overhead of an XSUB; the user should be able to create PP code. Simon
248 Cozens has some ideas on this.
250 =head2 DLL Versioning
252 Windows needs a way to know what version of an XS or C<libperl> DLL it's
255 =head2 Introduce @( and @)
257 C<$(> may return "foo bar baz". Unfortunately, since groups can
258 theoretically have spaces in their names, this could be one, two or
261 =head2 Floating point handling
263 C<NaN> and C<inf> support is particularly troublesome.
264 (fp_classify(), fp_class(), fp_class_d(), class(), isinf(),
265 isfinite(), finite(), isnormal(), unordered(), <ieeefp.h>,
266 <fp_class.h> (there are metaconfig units for all these) (I think),
267 fp_setmask(), fp_getmask(), fp_setround(), fp_getround()
268 (no metaconfig units yet for these). Don't forget finitel(), fp_classl(),
269 fp_class_l(), (yes, both do, unfortunately, exist), and unorderedl().)
271 As of Perl 5.6.1, there is a Perl macro, Perl_isnan().
273 =head2 IV/UV preservation
275 Nicholas Clark has done a lot of work on this, but work is continuing.
276 C<+>, C<-> and C<*> work, but guards need to be in place for C<%>, C</>,
277 C<&>, C<oct>, C<hex> and C<pack>.
279 =head2 Replace pod2html with something using Pod::Parser
281 The CPAN module C<Marek::Pod::Html> may be a more suitable basis for a
282 C<pod2html> converter; the current one duplicates the functionality
283 abstracted in C<Pod::Parser>, which makes updating the POD language
286 =head2 Automate module testing on CPAN
288 When a new Perl is being beta tested, porters have to manually grab
289 their favourite CPAN modules and test them - this should be done
292 =head2 sendmsg and recvmsg
294 We have all the other BSD socket functions but these. There are
295 metaconfig units for these functions which can be added. To avoid these
296 being new opcodes, a solution similar to the way C<sockatmark> was added
297 would be preferable. (Autoload the C<IO::whatever> module.)
299 =head2 Rewrite perlre documentation
301 The new-style patterns need full documentation, and the whole document
302 needs to be a lot clearer.
304 =head2 Convert example code to IO::Handle filehandles
306 =head2 Document Win32 choices
308 =head2 Check new modules
310 =head2 Make roffitall find pods and libs itself
312 Simon Cozens has done some work on this but it needs a rethink.
314 =head1 To do at some point
316 These are ideas that have been regularly tossed around, that most
317 people believe should be done maybe during 5.8.x
319 =head2 Remove regular expression recursion
321 Because the regular expression engine is recursive, badly designed
322 expressions can lead to lots of recursion filling up the stack. Ilya
323 claims that it is easy to convert the engine to being iterative, but
324 this has still not yet been done. There may be a regular expression
325 engine hit squad meeting at TPC5.
327 =head2 Memory leaks after failed eval
329 Perl will leak memory if you C<eval "hlagh hlagh hlagh hlagh">. This is
330 partially because it attempts to build up an op tree for that code and
331 doesn't properly free it. The same goes for non-syntactically-correct
332 regular expressions. Hugo looked into this, but decided it needed a
333 mark-and-sweep GC implementation.
335 Alan notes that: The basic idea was to extend the parser token stack
336 (C<YYSTYPE>) to include a type field so we knew what sort of thing each
337 element of the stack was. The F<perly.c> code would then have to be
338 postprocessed to record the type of each entry on the stack as it was
339 created, and the parser patched so that it could unroll the stack
342 This is possible to do, but would be pretty messy to implement, as it
343 would rely on even more sed hackery in F<perly.fixer>.
345 =head2 bitfields in pack
347 =head2 Cross compilation
349 Make Perl buildable with a cross-compiler. This will play havoc with
350 Configure, which needs to know how the target system will respond to
351 its tests; maybe C<microperl> will be a good starting point here.
352 (Indeed, Bart Schuller reports that he compiled up C<microperl> for
353 the Agenda PDA and it works fine.) A really big spanner in the works
354 is the bootstrapping build process of Perl: if the filesystem the
355 target systems sees is not the same what the build host sees, various
356 input, output, and (Perl) library files need to be copied back and forth.
358 As of 5.8.0 Configure mostly works for cross-compilation
359 (used successfully for iPAQ Linux), miniperl gets built,
360 but then building DynaLoader (and other extensions) fails
361 since MakeMaker knows nothing of cross-compilation.
362 (See INSTALL/Cross-compilation for the state of things.)
364 =head2 Perl preprocessor / macros
366 Source filters help with this, but do not get us all the way. For
367 instance, it should be possible to implement the C<??> operator somehow;
368 source filters don't (quite) cut it.
370 =head2 Perl lexer in Perl
372 Damian Conway is planning to work on this, but it hasn't happened yet.
374 =head2 Using POSIX calls internally
376 When faced with a BSD vs. SysV -style interface to some library or
377 system function, perl's roots show in that it typically prefers the BSD
378 interface (but falls back to the SysV one). One example is getpgrp().
379 Other examples include C<memcpy> vs. C<bcopy>. There are others, mostly in
382 Mostly, this item is a suggestion for which way to start a journey into
383 an C<#ifdef> forest. It is not primarily a suggestion to eliminate any of
384 the C<#ifdef> forests.
386 POSIX calls are perhaps more likely to be portable to unexpected
387 architectures. They are also perhaps more likely to be actively
388 maintained by a current vendor. They are also perhaps more likely to be
389 available in thread-safe versions, if appropriate.
391 =head2 -i rename file when changed
393 It's only necessary to rename a file when inplace editing when the file
394 has changed. Detecting a change is perhaps the difficult bit.
396 =head2 All ARGV input should act like E<lt>E<gt>
398 eg C<read(ARGV, ...)> doesn't currently read across multiple files.
400 =head2 Support for rerunning debugger
402 There should be a way of restarting the debugger on demand.
404 =head2 Test Suite for the Debugger
406 The debugger is a complex piece of software and fixing something
407 here may inadvertently break something else over there. To tame
408 this chaotic behaviour, a test suite is necessary.
410 =head2 my sub foo { }
412 The basic principle is sound, but there are problems with the semantics
413 of self-referential and mutually referential lexical subs: how to
416 =head2 One-pass global destruction
418 Sweeping away all the allocated memory in one go is a laudable goal, but
419 it's difficult and in most cases, it's easier to let the memory get
422 =head2 Rewrite regexp parser
424 There has been talk recently of rewriting the regular expression parser
425 to produce an optree instead of a chain of opcodes; it's unclear whether
426 or not this would be a win.
428 =head2 Cache recently used regexps
432 for my $re (@regexps) {
436 C<qr//> already gives us a way of saving compiled regexps, but it should
437 be done automatically.
439 =head2 Cross-compilation support
441 Bart Schuller reports that using C<microperl> and a cross-compiler, he
442 got Perl working on the Agenda PDA. However, one cannot build a full
443 Perl because Configure needs to get the results for the target platform,
446 =head2 Bit-shifting bitvectors
450 vec($v, 1000, 1) = 1;
452 One should be able to do
456 and have the 999'th bit set.
458 Currently if you try with shift bitvectors you shift the NV/UV, instead
459 of the bits in the PV. Not very logical.
461 =head2 debugger pragma
463 The debugger is implemented in Perl in F<perl5db.pl>; turning it into a
464 pragma should be easy, but making it work lexically might be more
465 difficult. Fiddling with C<$^P> would be necessary.
467 =head2 use less pragma
469 Identify areas where speed/memory tradeoffs can be made and have a hint
470 to switch between them.
472 =head2 switch structures
474 Although we have C<Switch.pm> in core, Larry points to the dormant
475 C<nswitch> and C<cswitch> ops in F<pp.c>; using these opcodes would be
478 =head2 Cache eval tree
482 =head2 Shrink opcode tables
484 =head2 Optimize away @_
486 Look at the "reification" code in C<av.c>
488 =head2 Prototypes versus indirect objects
490 Currently, indirect object syntax bypasses prototype checks.
494 HTML versions of the documentation need to be installed by default; a
495 call to C<installhtml> from C<installperl> may be all that's necessary.
497 =head2 Prototype method calls
499 =head2 Return context prototype declarations
503 =head2 Garbage collection
505 There have been persistent mumblings about putting a mark-and-sweep
506 garbage detector into Perl; Alan Burlison has some ideas about this.
510 Mark-Jason Dominus has the beginnings of one of these.
512 =head2 Rewrite perldoc
514 There are a few suggestions for what to do with C<perldoc>: maybe a
515 full-text search, an index function, locating pages on a particular
516 high-level subject, and so on.
518 =head2 Install .3p manpages
520 This is a bone of contention; we can create C<.3p> manpages for each
521 built-in function, but should we install them by default? Tcl does this,
522 and it clutters up C<apropos>.
524 =head2 Unicode tutorial
526 Simon Cozens promises to do this before he gets old.
528 =head2 Update POSIX.pm for 1003.1-2
530 =head2 Retargetable installation
532 Allow C<@INC> to be changed after Perl is built.
534 =head2 POSIX emulation on non-POSIX systems
536 Make C<POSIX.pm> behave as POSIXly as possible everywhere, meaning we
537 have to implement POSIX equivalents for some functions if necessary.
539 =head2 Rename Win32 headers
541 =head2 Finish off lvalue functions
543 They don't work in the debugger, and they don't work for list or hash
546 =head2 Update sprintf documentation
548 Hugo van der Sanden plans to look at this.
550 =head2 Use fchown/fchmod internally
552 This has been done in places, but needs a thorough code review.
553 Also fchdir is available in some platforms.
555 =head2 Make v-strings overloaded objects
557 Instead of having to guess whether a string is a v-string and thus
558 needs to be displayed with %vd, make v-strings (readonly) objects
559 (class "vstring"?) with a stringify overload.
561 =head2 Allow restricted hash assignment
563 Currently you're not allowed to assign to a restricted hash at all,
564 even with the same keys.
566 %restricted = (foo => 42); # error
568 This should be allowed if the new keyset is a subset of the old
569 keyset. May require more extra code than we'd like in pp_aassign.
571 =head2 Should overload be inheritable?
573 Should overload be 'contagious' through @ISA so that derived classes
574 would inherit their base classes' overload definitions? What to do
575 in case of overload conflicts?
579 Should taint be stopped from affecting control flow, if ($tainted)?
580 Should tainted symbolic method calls and subref calls be stopped?
581 (Look at Ruby's $SAFE levels for inspiration?)
583 =head2 Perform correctly when XSUBs call subroutines that exit via goto(LABEL) and friends
585 If an XSUB calls a subroutine that exits using goto(LABEL),
586 last(LABEL) or next(LABEL), then the interpreter will very probably crash
587 with a segfault because the execution resumes in the XSUB instead of
588 never returning there.
592 Ideas which have been discussed, and which may or may not happen.
594 =head2 ref() in list context
596 It's unclear what this should do or how to do it without breaking old
599 =head2 Make tr/// return histogram of characters in list context
601 There is a patch for this, but it may require Unicodification.
603 =head2 Compile to real threaded code
605 =head2 Structured types
607 =head2 Modifiable $1 et al.
609 ($x = "elephant") =~ /e(ph)/;
610 $1 = "g"; # $x = "elegant"
612 What happens if there are multiple (nested?) brackets? What if the
613 string changes between the match and the assignment?
615 =head2 Procedural interfaces for IO::*, etc.
617 Some core modules have been accused of being overly-OO. Adding
618 procedural interfaces could demystify them.
622 =head2 Attach/detach debugger from running program
624 With C<gdb>, you can attach the debugger to a running program if you
625 pass the process ID. It would be good to do this with the Perl debugger
626 on a running Perl program, although I'm not sure how it would be done.
630 A non-core module that would use "native" GUI to create graphical
633 =head2 foreach(reverse ...)
637 foreach (reverse @_) { ... }
639 puts C<@_> on the stack, reverses it putting the reversed version on the
640 stack, then iterates forwards. Instead, it could be special-cased to put
641 C<@_> on the stack then iterate backwards.
643 =head2 Constant function cache
645 =head2 Approximate regular expression matching
649 These items B<always> need doing:
651 =head2 Update guts documentation
653 Simon Cozens tries to do this when possible, and contributions to the
654 C<perlapi> documentation is welcome.
656 =head2 Add more tests
658 Michael Schwern will donate $500 to Yet Another Society when all core
661 =head2 Update auxiliary tools
663 The code we ship with Perl should look like good Perl 5.
665 =head2 Create debugging macros
667 Debugging macros (like printsv, dump) can make debugging perl inside a
668 C debugger much easier. A good set for gdb comes with mod_perl.
669 Something similar should be distributed with perl.
671 The proper way to do this is to use and extend Devel::DebugInit.
672 Devel::DebugInit also needs to be extended to support threads.
674 See p5p archives for late May/early June 2001 for a recent discussion
677 =head2 truncate to the people
679 One can emulate ftruncate() using F_FREESP and F_CHSIZ fcntls
680 (see the UNIX FAQ for details). This needs to go somewhere near
681 pp_sys.c:pp_truncate().
683 One can emulate truncate() easily if one has ftruncate().
684 This emulation should also go near pp_sys.pp_truncate().
686 =head2 Unicode in Filenames
688 chdir, chmod, chown, chroot, exec, glob, link, lstat, mkdir, open,
689 opendir, qx, readdir, readlink, rename, rmdir, stat, symlink, sysopen,
690 system, truncate, unlink, utime, -X. All these could potentially accept
691 Unicode filenames either as input or output (and in the case of system
692 and qx Unicode in general, as input or output to/from the shell).
693 Whether a filesystem - an operating system pair understands Unicode in
696 Known combinations that have some level of understanding include
697 Microsoft NTFS, Apple HFS+ (In Mac OS 9 and X) and Apple UFS (in Mac
698 OS X), NFS v4 is rumored to be Unicode, and of course Plan 9. How to
699 create Unicode filenames, what forms of Unicode are accepted and used
700 (UCS-2, UTF-16, UTF-8), what (if any) is the normalization form used,
701 and so on, varies. Finding the right level of interfacing to Perl
702 requires some thought. Remember that an OS does not implicate a
705 (The Windows -C command flag "wide API support" has been at least
706 temporarily retired in 5.8.1, and the -C has been repurposed, see
709 =head1 Unicode in %ENV
711 Currently the %ENV entries are always byte strings.
713 =head1 Recently done things
715 These are things which have been on the todo lists in previous releases
716 but have recently been completed.
718 =head2 Alternative RE syntax module
720 The C<Regexp::English> module, available from the CPAN, provides this:
722 my $re = Regexp::English
724 -> literal('Flippers')
735 =head2 Safe signal handling
737 A new signal model went into 5.7.1 without much fanfare. Operations and
738 C<malloc>s are no longer interrupted by signals, which are handled
739 between opcodes. This means that C<PERL_ASYNC_CHECK> now actually does
740 something. However, there are still a few things that need to be done.
744 Modules which implement arrays in terms of strings, substrings or files
745 can be found on the CPAN.
749 C<Time::HiRes> has been integrated into the core.
751 =head2 setitimer and getimiter
753 Adding C<Time::HiRes> got us this too.
755 =head2 Testing __DIE__ hook
757 Tests have been added.
759 =head2 CPP equivalent in Perl
761 A C Yardley will probably have done this by the time you can read this.
762 This allows for a generalization of the C constant detection used in
763 building C<Errno.pm>.
765 =head2 Explicit switch statements
767 C<Switch.pm> has been integrated into the core to give you all manner of
768 C<switch...case> semantics.
776 Nick Ing-Simmons has made UTF-EBCDIC (UTR13) work with Perl.
778 EBCDIC? http://www.unicode.org/unicode/reports/tr16/
782 Although there are probably some small bugs to be rooted out, Jarkko
783 Hietaniemi has made regular expressions polymorphic between bytes and
786 =head2 perlcc to produce executable
788 C<perlcc> was recently rewritten, and can now produce standalone
791 =head2 END blocks saved in compiled output
793 =head2 Secure temporary file module
795 Tim Jenness' C<File::Temp> is now in core.
797 =head2 Integrate Time::HiRes
799 This module is now part of core.
801 =head2 Turn Cwd into XS
803 Benjamin Sugars has done this.
805 =head2 Mmap for input
807 Nick Ing-Simmons' C<perlio> supports an C<mmap> IO method.
809 =head2 Byte to/from UTF-8 and UTF-8 to/from local conversion
811 C<Encode> provides this.
813 =head2 Add sockatmark support
817 =head2 Mailing list archives
819 http://lists.perl.org/ , http://archive.develooper.com/
823 Since 5.8.0 perl uses the RT bug tracking system from Jesse Vincent,
824 implemented by Robert Spier at http://bugs.perl.org/
826 =head2 Integrate MacPerl
828 Chris Nandor and Matthias Neeracher have integrated the MacPerl changes
831 =head2 Web "nerve center" for Perl
833 http://use.perl.org/ is what you're looking for.
835 =head2 Regular expression tutorial
837 C<perlretut>, provided by Mark Kvale.
839 =head2 Debugging Tutorial
841 C<perldebtut>, written by Richard Foley.
843 =head2 Integrate new modules
845 Jarkko has been integrating madly into 5.7.x
847 =head2 Integrate profiler
849 C<Devel::DProf> is now a core module.
851 =head2 Y2K error detection
853 There's a configure option to detect unsafe concatenation with "19", and
854 a CPAN module. (C<D'oh::Year>)
856 =head2 Regular expression debugger
858 While not part of core, Mark-Jason Dominus has written C<Rx> and has
859 also come up with a generalised strategy for regular expression
864 That's, uh, F<podchecker>
866 =head2 "Dynamic" lexicals
868 =head2 Cache precompiled modules
870 =head2 "or" tests defined, not truth
874 =head1 Deprecated Wishes
876 These are items which used to be in the todo file, but have been
877 deprecated for some reason.
879 =head2 Loop control on do{}
881 This would break old code; use C<do{{ }}> instead.
883 =head2 Lexically scoped typeglobs
885 Not needed now we have lexical IO handles.
891 Damian Conway's text formatting modules seem to be the Way To Go.
893 =head2 Generalised want()/caller())
895 Robin Houston's C<Want> module does this.
897 =head2 Named prototypes
899 This seems to be delayed until Perl 6.
901 =head2 Built-in globbing
903 The C<File::Glob> module has been used to replace the C<glob> function.
905 =head2 Regression tests for suidperl
907 C<suidperl> is deprecated in favour of common sense.
909 =head2 Cached hash values
911 We have shared hash keys, which perform the same job.
913 =head2 Add compression modules
915 The compression modules are a little heavy; meanwhile, Nicholas Clark is
916 working on experimental pragmata to do transparent decompression on
919 =head2 Reorganise documentation into tutorials/references
921 Could not get consensus on P5P about this.
923 =head2 Remove distinction between functions and operators
925 Caution: highly flammable.
927 =head2 Make XS easier to use
929 Use C<Inline> instead, or SWIG.
931 =head2 Make embedding easier to use
937 See the Perl Power Tools. ( http://language.perl.com/ppt/ )
939 =head2 my $Package::variable
943 =head2 "class"-based lexicals
945 Use flyweight objects, secure hashes or, dare I say it, pseudo-hashes instead.
946 (Or whatever will replace pseudohashes in 5.10.)
950 C<ByteLoader> covers this.
952 =head2 Lazy evaluation / tail recursion removal
954 C<List::Util> gives first() (a short-circuiting grep); tail recursion
955 removal is done manually, with C<goto &whoami;>. (However, MJD has
956 found that C<goto &whoami> introduces a performance penalty, so maybe
957 there should be a way to do this after all: C<sub foo {START: ... goto
960 =head2 Make "use utf8" the default
962 Because of backward compatibility this is difficult: scripts could not
963 contain B<any legacy eight-bit data> (like Latin-1) anymore, even in
964 string literals or pod. Also would introduce a measurable slowdown of
965 at least few percentages since all regular expression operations would
966 be done in full UTF-8. But if you want to try this, add
967 -DUSE_UTF8_SCRIPTS to your compilation flags.
969 =head2 Unicode collation and normalization
971 The Unicode::Collate and Unicode::Normalize modules
972 by SADAHIRO Tomoyuki have been included since 5.8.0.
974 Collation? http://www.unicode.org/unicode/reports/tr10/
975 Normalization? http://www.unicode.org/unicode/reports/tr15/
977 =head2 pack/unpack tutorial
979 Wolfgang Laun finished what Simon Cozens started.