perltodo update.
[p5sagit/p5-mst-13.2.git] / pod / perltodo.pod
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7711098a 1=head1 NAME
2
3perltodo - Perl TO-DO List
4
5=head1 DESCRIPTION
e50bb9a1 6
722d2a37 7This is a list of wishes for Perl. Send updates to
e50bb9a1 8I<perl5-porters@perl.org>. If you want to work on any of these
9projects, be sure to check the perl5-porters archives for past ideas,
10flames, and propaganda. This will save you time and also prevent you
11from implementing something that Larry has already vetoed. One set
12of archives may be found at:
13
14 http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/
15
722d2a37 16=head1 To do during 5.6.x
e50bb9a1 17
722d2a37 18=head2 Support for I/O disciplines
e50bb9a1 19
722d2a37 20C<perlio> provides this, but the interface could be a lot more
21straightforward.
e50bb9a1 22
4b3b956a 23=head2 Autoload bytes.pm
e50bb9a1 24
4b3b956a 25When the lexer sees, for instance, C<bytes::length>, it should
26automatically load the C<bytes> pragma.
27
28=head2 Make "\u{XXXX}" et al work
29
30Danger, Will Robinson! Discussing the semantics of C<"\x{F00}">,
31C<"\xF00"> and C<"\U{F00}"> on P5P I<will> lead to a long and boring
32flamewar.
e50bb9a1 33
c6287c21 34=head2 Create a char *sv_pvprintify(sv, STRLEN *lenp, UV flags)
0562c0e3 35
36For displaying PVs with control characters, embedded nulls, and Unicode.
37This would be useful for printing warnings, or data and regex dumping,
38not_a_number(), and so on.
39
f35392ae 40Requirements: should handle both byte and UTF8 strings. isPRINT()
41characters printed as-is, character less than 256 as \xHH, Unicode
0661e9a4 42characters as \x{HHH}. Don't assume ASCII-like, either, get somebody
43on EBCDIC to test the output.
f35392ae 44
45Possible options, controlled by the flags:
0661e9a4 46- whitespace (other than ' ' of isPRINT()) printed as-is
f35392ae 47- use isPRINT_LC() instead of isPRINT()
48- print control characters like this: "\cA"
49- print control characters like this: "^A"
0661e9a4 50- non-PRINTables printed as '.' instead of \xHH
51- use \OOO instead of \xHH
52- use the C/Perl-metacharacters like \n, \t
f35392ae 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
0661e9a4 55- really fancy: print unicode characters as \N{...}
f35392ae 56
1626a787 57NOTE: pv_display(), pv_uni_display(), sv_uni_display() are already
58doing something like the above.
c5fc23ff 59
722d2a37 60=head2 Overloadable regex assertions
e50bb9a1 61
722d2a37 62This may or may not be possible with the current regular expression
63engine. The idea is that, for instance, C<\b> needs to be
64algorithmically computed if you're dealing with Thai text. Hence, the
65B<\b> assertion wants to be overloaded by a function.
e50bb9a1 66
776f8809 67=head2 Unicode
68
69=over 4
70
71=item *
e50bb9a1 72
f34dec15 73Allow for long form of the General Category Properties, e.g
74C<\p{IsOpenPunctuation}>, not just the abbreviated form, e.g.
75C<\p{IsPs}>.
76
77=item *
78
1ac13f9a 79Allow for the metaproperties: C<XID Start>, C<XID Continue>,
80C<NF*_NO>, C<NF*_MAYBE> (require the DerivedCoreProperties and
81DerviceNormalizationProperties files).
f34dec15 82
71d929cb 83There are also multiple value properties still unimplemented:
84C<Numeric Type>, C<East Asian Width>.
f34dec15 85
86=item *
87
722d2a37 88 Case Mappings? http://www.unicode.org/unicode/reports/tr21/
e50bb9a1 89
6f16a292 90lc(), uc(), lcfirst(), and ucfirst() work only for some of the
91simplest cases, where the mapping goes from a single Unicode character
92to another single Unicode character. See lib/unicore/SpecCase.txt
93(and CaseFold.txt).
ac1256e8 94
776f8809 95=item *
e50bb9a1 96
8d3e8850 97UTF-8 identifier names should probably be canonicalized: NFC?
e50bb9a1 98
20eafb1c 99=item *
100
101UTF-8 in package names and sub names? The first is problematic
8d3e8850 102because of the mapping to pathnames, ditto for the second one if
20eafb1c 103one does autosplitting, for example.
e50bb9a1 104
776f8809 105=back
106
107See L<perlunicode/UNICODE REGULAR EXPRESSION SUPPORT LEVEL> for what's
f34dec15 108there and what's missing. Almost all of Levels 2 and 3 is missing,
109and as of 5.8.0 not even all of Level 1 is there.
8d3e8850 110They have some tricks Perl doesn't yet implement, such as character
20eafb1c 111class subtraction.
112
113 http://www.unicode.org/unicode/reports/tr18/
776f8809 114
56490ca2 115=head2 Work out exit/die semantics for threads
e50bb9a1 116
97b33923 117There are some suggestions to use for example something like this:
118default to "(thread exiting first will) wait for the other threads
119until up to 60 seconds". Other possibilities:
120
121 use threads wait => 0;
122
123Do not wait.
124
125 use threads wait_for => 10;
126
127Wait up to 10 seconds.
128
129 use threads wait_for => -1;
130
131Wait for ever.
e50bb9a1 132
56490ca2 133http://archive.develooper.com/perl5-porters@perl.org/msg79618.html
dd0afe54 134
56490ca2 135=head2 Better support for nonpreemptive threading systems like PTH
dd0afe54 136
56490ca2 137Perhaps do yield() before blocking calls, exchange calls to non blocking
138calls specific for those libraries (for example GNUpth has a pth_sleep
139which is a non pth aware version of sleep).
e50bb9a1 140
722d2a37 141=head2 Typed lexicals for compiler
e50bb9a1 142
722d2a37 143=head2 Compiler workarounds for Win32
e50bb9a1 144
722d2a37 145=head2 AUTOLOADing in the compiler
e50bb9a1 146
722d2a37 147=head2 Fixing comppadlist when compiling
e50bb9a1 148
722d2a37 149=head2 Cleaning up exported namespace
e50bb9a1 150
722d2a37 151=head2 Complete signal handling
e50bb9a1 152
722d2a37 153Add C<PERL_ASYNC_CHECK> to opcodes which loop; replace C<sigsetjmp> with
154C<sigjmp>; check C<wait> for signal safety.
e50bb9a1 155
722d2a37 156=head2 Out-of-source builds
e50bb9a1 157
722d2a37 158This was done for 5.6.0, but needs reworking for 5.7.x
e50bb9a1 159
722d2a37 160=head2 POSIX realtime support
e50bb9a1 161
722d2a37 162POSIX 1003.1 1996 Edition support--realtime stuff: POSIX semaphores,
163message queues, shared memory, realtime clocks, timers, signals (the
164metaconfig units mostly already exist for these)
e50bb9a1 165
722d2a37 166=head2 UNIX98 support
e50bb9a1 167
722d2a37 168Reader-writer locks, realtime/asynchronous IO
e50bb9a1 169
722d2a37 170=head2 IPv6 Support
e50bb9a1 171
fe854a6f 172There are non-core modules, such as C<Socket6>, but these will need
722d2a37 173integrating when IPv6 actually starts to really happen. See RFC 2292
174and RFC 2553.
e50bb9a1 175
722d2a37 176=head2 Long double conversion
e50bb9a1 177
722d2a37 178Floating point formatting is still causing some weird test failures.
e50bb9a1 179
722d2a37 180=head2 Locales
e50bb9a1 181
722d2a37 182Locales and Unicode interact with each other in unpleasant ways.
183One possible solution would be to adopt/support ICU:
e50bb9a1 184
722d2a37 185 http://oss.software.ibm.com/developerworks/opensource/icu/project/
e50bb9a1 186
722d2a37 187=head2 Arithmetic on non-Arabic numerals
e50bb9a1 188
722d2a37 189C<[1234567890]> aren't the only numerals any more.
e50bb9a1 190
722d2a37 191=head2 POSIX Unicode character classes
e50bb9a1 192
97b33923 193(C<[=a=]> for equivalence classes, C<[.ch.]> for collation.)
722d2a37 194These are dependent on Unicode normalization and collation.
e50bb9a1 195
722d2a37 196=head2 Factoring out common suffices/prefices in regexps (trie optimization)
c47ff5f1 197
722d2a37 198Currently, the user has to optimize C<foo|far> and C<foo|goo> into
199C<f(?:oo|ar)> and C<[fg]oo> by hand; this could be done automatically.
e50bb9a1 200
722d2a37 201=head2 Security audit shipped utilities
e50bb9a1 202
722d2a37 203All the code we ship with Perl needs to be sensible about temporary file
204handling, locking, input validation, and so on.
e50bb9a1 205
c8d2171d 206=head2 Sort out the uid-setting mess
207
208Currently there are several problems with the setting of uids ($<, $>
209for the real and effective uids). Firstly, what exactly setuid() call
210gets invoked in which platform is simply a big mess that needs to be
211untangled. Secondly, the effects are apparently not standard across
212platforms, (if you first set $< and then $>, or vice versa, being
666f95b9 213uid == euid == zero, or just euid == zero, or as a normal user, what are
c8d2171d 214the results?). The test suite not (usually) being run as root means
215that these things do not get much testing. Thirdly, there's quite
216often a third uid called saved uid, and Perl has no knowledge of that
217feature in any way. (If one has the saved uid of zero, one can get
218back any real and effective uids.) As an example, to change also the
219saved uid, one needs to set the real and effective uids B<twice>-- in
220most systems, that is: in HP-UX that doesn't seem to work.
666f95b9 221
722d2a37 222=head2 Custom opcodes
e50bb9a1 223
722d2a37 224Have a way to introduce user-defined opcodes without the subroutine call
225overhead of an XSUB; the user should be able to create PP code. Simon
226Cozens has some ideas on this.
e50bb9a1 227
722d2a37 228=head2 DLL Versioning
e50bb9a1 229
d1be9408 230Windows needs a way to know what version of an XS or C<libperl> DLL it's
722d2a37 231loading.
e50bb9a1 232
722d2a37 233=head2 Introduce @( and @)
e50bb9a1 234
722d2a37 235C<$(> may return "foo bar baz". Unfortunately, since groups can
236theoretically have spaces in their names, this could be one, two or
237three groups.
e50bb9a1 238
722d2a37 239=head2 Floating point handling
e50bb9a1 240
722d2a37 241C<NaN> and C<inf> support is particularly troublesome.
242(fp_classify(), fp_class(), fp_class_d(), class(), isinf(),
243isfinite(), finite(), isnormal(), unordered(), <ieeefp.h>,
244<fp_class.h> (there are metaconfig units for all these) (I think),
245fp_setmask(), fp_getmask(), fp_setround(), fp_getround()
246(no metaconfig units yet for these). Don't forget finitel(), fp_classl(),
247fp_class_l(), (yes, both do, unfortunately, exist), and unorderedl().)
e50bb9a1 248
210b36aa 249As of Perl 5.6.1, there is a Perl macro, Perl_isnan().
e50bb9a1 250
722d2a37 251=head2 IV/UV preservation
e50bb9a1 252
722d2a37 253Nicholas Clark has done a lot of work on this, but work is continuing.
254C<+>, C<-> and C<*> work, but guards need to be in place for C<%>, C</>,
255C<&>, C<oct>, C<hex> and C<pack>.
e50bb9a1 256
722d2a37 257=head2 Replace pod2html with something using Pod::Parser
83df6a1d 258
fe854a6f 259The CPAN module C<Marek::Pod::Html> may be a more suitable basis for a
97b33923 260C<pod2html> converter; the current one duplicates the functionality
722d2a37 261abstracted in C<Pod::Parser>, which makes updating the POD language
262difficult.
e50bb9a1 263
722d2a37 264=head2 Automate module testing on CPAN
e50bb9a1 265
722d2a37 266When a new Perl is being beta tested, porters have to manually grab
267their favourite CPAN modules and test them - this should be done
268automatically.
e50bb9a1 269
722d2a37 270=head2 sendmsg and recvmsg
83df6a1d 271
722d2a37 272We have all the other BSD socket functions but these. There are
273metaconfig units for these functions which can be added. To avoid these
274being new opcodes, a solution similar to the way C<sockatmark> was added
275would be preferable. (Autoload the C<IO::whatever> module.)
e50bb9a1 276
722d2a37 277=head2 Rewrite perlre documentation
e50bb9a1 278
722d2a37 279The new-style patterns need full documentation, and the whole document
280needs to be a lot clearer.
e50bb9a1 281
722d2a37 282=head2 Convert example code to IO::Handle filehandles
e50bb9a1 283
722d2a37 284=head2 Document Win32 choices
e50bb9a1 285
722d2a37 286=head2 Check new modules
e50bb9a1 287
722d2a37 288=head2 Make roffitall find pods and libs itself
e50bb9a1 289
722d2a37 290Simon Cozens has done some work on this but it needs a rethink.
e50bb9a1 291
722d2a37 292=head1 To do at some point
e50bb9a1 293
722d2a37 294These are ideas that have been regularly tossed around, that most
295people believe should be done maybe during 5.8.x
e50bb9a1 296
722d2a37 297=head2 Remove regular expression recursion
e50bb9a1 298
722d2a37 299Because the regular expression engine is recursive, badly designed
300expressions can lead to lots of recursion filling up the stack. Ilya
301claims that it is easy to convert the engine to being iterative, but
302this has still not yet been done. There may be a regular expression
303engine hit squad meeting at TPC5.
e50bb9a1 304
722d2a37 305=head2 Memory leaks after failed eval
e50bb9a1 306
722d2a37 307Perl will leak memory if you C<eval "hlagh hlagh hlagh hlagh">. This is
308partially because it attempts to build up an op tree for that code and
309doesn't properly free it. The same goes for non-syntactically-correct
310regular expressions. Hugo looked into this, but decided it needed a
311mark-and-sweep GC implementation.
e50bb9a1 312
722d2a37 313Alan notes that: The basic idea was to extend the parser token stack
314(C<YYSTYPE>) to include a type field so we knew what sort of thing each
210b36aa 315element of the stack was. The F<perly.c> code would then have to be
722d2a37 316postprocessed to record the type of each entry on the stack as it was
317created, and the parser patched so that it could unroll the stack
318properly on error.
e50bb9a1 319
722d2a37 320This is possible to do, but would be pretty messy to implement, as it
321would rely on even more sed hackery in F<perly.fixer>.
e50bb9a1 322
722d2a37 323=head2 bitfields in pack
e50bb9a1 324
722d2a37 325=head2 Cross compilation
e50bb9a1 326
722d2a37 327Make Perl buildable with a cross-compiler. This will play havoc with
da75cd15 328Configure, which needs to know how the target system will respond to
722d2a37 329its tests; maybe C<microperl> will be a good starting point here.
330(Indeed, Bart Schuller reports that he compiled up C<microperl> for
331the Agenda PDA and it works fine.) A really big spanner in the works
332is the bootstrapping build process of Perl: if the filesystem the
333target systems sees is not the same what the build host sees, various
334input, output, and (Perl) library files need to be copied back and forth.
e50bb9a1 335
f86a8bc5 336As of 5.8.0 Configure mostly works for cross-compilation
337(used successfully for iPAQ Linux), miniperl gets built,
338but then building DynaLoader (and other extensions) fails
339since MakeMaker knows nothing of cross-compilation.
340(See INSTALL/Cross-compilation for the state of things.)
341
722d2a37 342=head2 Perl preprocessor / macros
e50bb9a1 343
722d2a37 344Source filters help with this, but do not get us all the way. For
345instance, it should be possible to implement the C<??> operator somehow;
346source filters don't (quite) cut it.
e50bb9a1 347
722d2a37 348=head2 Perl lexer in Perl
a45bd81d 349
722d2a37 350Damian Conway is planning to work on this, but it hasn't happened yet.
e50bb9a1 351
722d2a37 352=head2 Using POSIX calls internally
e50bb9a1 353
210b36aa 354When faced with a BSD vs. SysV -style interface to some library or
722d2a37 355system function, perl's roots show in that it typically prefers the BSD
356interface (but falls back to the SysV one). One example is getpgrp().
357Other examples include C<memcpy> vs. C<bcopy>. There are others, mostly in
210b36aa 358F<pp_sys.c>.
e50bb9a1 359
722d2a37 360Mostly, this item is a suggestion for which way to start a journey into
361an C<#ifdef> forest. It is not primarily a suggestion to eliminate any of
362the C<#ifdef> forests.
e50bb9a1 363
722d2a37 364POSIX calls are perhaps more likely to be portable to unexpected
365architectures. They are also perhaps more likely to be actively
366maintained by a current vendor. They are also perhaps more likely to be
367available in thread-safe versions, if appropriate.
e50bb9a1 368
722d2a37 369=head2 -i rename file when changed
e50bb9a1 370
722d2a37 371It's only necessary to rename a file when inplace editing when the file
372has changed. Detecting a change is perhaps the difficult bit.
e50bb9a1 373
722d2a37 374=head2 All ARGV input should act like E<lt>E<gt>
e50bb9a1 375
2d84a16a 376eg C<read(ARGV, ...)> doesn't currently read across multiple files.
377
722d2a37 378=head2 Support for rerunning debugger
e50bb9a1 379
722d2a37 380There should be a way of restarting the debugger on demand.
e50bb9a1 381
c6287c21 382=head2 Test Suite for the Debugger
383
384The debugger is a complex piece of software and fixing something
385here may inadvertently break something else over there. To tame
386this chaotic behaviour, a test suite is necessary.
387
722d2a37 388=head2 my sub foo { }
c47ff5f1 389
722d2a37 390The basic principle is sound, but there are problems with the semantics
391of self-referential and mutually referential lexical subs: how to
392declare the subs?
c47ff5f1 393
722d2a37 394=head2 One-pass global destruction
c47ff5f1 395
722d2a37 396Sweeping away all the allocated memory in one go is a laudable goal, but
397it's difficult and in most cases, it's easier to let the memory get
398freed by exiting.
e50bb9a1 399
722d2a37 400=head2 Rewrite regexp parser
e50bb9a1 401
722d2a37 402There has been talk recently of rewriting the regular expression parser
403to produce an optree instead of a chain of opcodes; it's unclear whether
404or not this would be a win.
e50bb9a1 405
722d2a37 406=head2 Cache recently used regexps
e50bb9a1 407
722d2a37 408This is to speed up
e50bb9a1 409
722d2a37 410 for my $re (@regexps) {
411 $matched++ if /$re/
412 }
e50bb9a1 413
722d2a37 414C<qr//> already gives us a way of saving compiled regexps, but it should
415be done automatically.
e50bb9a1 416
722d2a37 417=head2 Cross-compilation support
04c70446 418
722d2a37 419Bart Schuller reports that using C<microperl> and a cross-compiler, he
420got Perl working on the Agenda PDA. However, one cannot build a full
421Perl because Configure needs to get the results for the target platform,
422for the host.
e50bb9a1 423
722d2a37 424=head2 Bit-shifting bitvectors
e50bb9a1 425
722d2a37 426Given:
e50bb9a1 427
722d2a37 428 vec($v, 1000, 1) = 1;
e50bb9a1 429
722d2a37 430One should be able to do
e50bb9a1 431
722d2a37 432 $v <<= 1;
e50bb9a1 433
722d2a37 434and have the 999'th bit set.
e50bb9a1 435
722d2a37 436Currently if you try with shift bitvectors you shift the NV/UV, instead
437of the bits in the PV. Not very logical.
e50bb9a1 438
722d2a37 439=head2 debugger pragma
e50bb9a1 440
722d2a37 441The debugger is implemented in Perl in F<perl5db.pl>; turning it into a
442pragma should be easy, but making it work lexically might be more
443difficult. Fiddling with C<$^P> would be necessary.
e50bb9a1 444
722d2a37 445=head2 use less pragma
e50bb9a1 446
722d2a37 447Identify areas where speed/memory tradeoffs can be made and have a hint
448to switch between them.
e50bb9a1 449
722d2a37 450=head2 switch structures
e50bb9a1 451
722d2a37 452Although we have C<Switch.pm> in core, Larry points to the dormant
453C<nswitch> and C<cswitch> ops in F<pp.c>; using these opcodes would be
454much faster.
e50bb9a1 455
722d2a37 456=head2 Cache eval tree
e50bb9a1 457
722d2a37 458=head2 rcatmaybe
e50bb9a1 459
722d2a37 460=head2 Shrink opcode tables
e50bb9a1 461
722d2a37 462=head2 Optimize away @_
e50bb9a1 463
722d2a37 464Look at the "reification" code in C<av.c>
e50bb9a1 465
722d2a37 466=head2 Prototypes versus indirect objects
e50bb9a1 467
722d2a37 468Currently, indirect object syntax bypasses prototype checks.
e50bb9a1 469
210b36aa 470=head2 Install HTML
e50bb9a1 471
722d2a37 472HTML versions of the documentation need to be installed by default; a
473call to C<installhtml> from C<installperl> may be all that's necessary.
e50bb9a1 474
722d2a37 475=head2 Prototype method calls
e50bb9a1 476
722d2a37 477=head2 Return context prototype declarations
e50bb9a1 478
722d2a37 479=head2 magic_setisa
e50bb9a1 480
722d2a37 481=head2 Garbage collection
e50bb9a1 482
722d2a37 483There have been persistent mumblings about putting a mark-and-sweep
484garbage detector into Perl; Alan Burlison has some ideas about this.
e50bb9a1 485
722d2a37 486=head2 IO tutorial
e50bb9a1 487
722d2a37 488Mark-Jason Dominus has the beginnings of one of these.
e50bb9a1 489
722d2a37 490=head2 Rewrite perldoc
e50bb9a1 491
722d2a37 492There are a few suggestions for what to do with C<perldoc>: maybe a
493full-text search, an index function, locating pages on a particular
494high-level subject, and so on.
e50bb9a1 495
3958b146 496=head2 Install .3p manpages
e50bb9a1 497
3958b146 498This is a bone of contention; we can create C<.3p> manpages for each
722d2a37 499built-in function, but should we install them by default? Tcl does this,
500and it clutters up C<apropos>.
e50bb9a1 501
722d2a37 502=head2 Unicode tutorial
e50bb9a1 503
722d2a37 504Simon Cozens promises to do this before he gets old.
e50bb9a1 505
722d2a37 506=head2 Update POSIX.pm for 1003.1-2
3958b146 507
722d2a37 508=head2 Retargetable installation
e50bb9a1 509
722d2a37 510Allow C<@INC> to be changed after Perl is built.
e50bb9a1 511
722d2a37 512=head2 POSIX emulation on non-POSIX systems
e50bb9a1 513
722d2a37 514Make C<POSIX.pm> behave as POSIXly as possible everywhere, meaning we
515have to implement POSIX equivalents for some functions if necessary.
e50bb9a1 516
722d2a37 517=head2 Rename Win32 headers
e50bb9a1 518
722d2a37 519=head2 Finish off lvalue functions
520
521They don't work in the debugger, and they don't work for list or hash
522slices.
e50bb9a1 523
722d2a37 524=head2 Update sprintf documentation
e50bb9a1 525
722d2a37 526Hugo van der Sanden plans to look at this.
e50bb9a1 527
722d2a37 528=head2 Use fchown/fchmod internally
e50bb9a1 529
722d2a37 530This has been done in places, but needs a thorough code review.
531Also fchdir is available in some platforms.
e50bb9a1 532
d45541b3 533=head2 Make v-strings overloaded objects
c5fc23ff 534
d45541b3 535Instead of having to guess whether a string is a v-string and thus
536needs to be displayed with %vd, make v-strings (readonly) objects
537(class "vstring"?) with a stringify overload.
c5fc23ff 538
49293501 539=head2 Allow restricted hash assignment
540
541Currently you're not allowed to assign to a restricted hash at all,
542even with the same keys.
543
544 %restricted = (foo => 42); # error
545
546This should be allowed if the new keyset is a subset of the old
547keyset. May require more extra code than we'd like in pp_aassign.
548
5387ccf1 549=head2 Should overload be inheritable?
550
551Should overload be 'contagious' through @ISA so that derived classes
552would inherit their base classes' overload definitions? What to do
553in case of overload conflicts?
554
cbda53d5 555=head2 Taint rethink
556
557Should taint be stopped from affecting control flow, if ($tainted)?
558Should tainted symbolic method calls and subref calls be stopped?
559(Look at Ruby's $SAFE levels for inspiration?)
560
722d2a37 561=head1 Vague ideas
e50bb9a1 562
722d2a37 563Ideas which have been discussed, and which may or may not happen.
e50bb9a1 564
722d2a37 565=head2 ref() in list context
e50bb9a1 566
722d2a37 567It's unclear what this should do or how to do it without breaking old
568code.
e50bb9a1 569
f86a8bc5 570=head2 Make tr/// return histogram of characters in list context
e50bb9a1 571
722d2a37 572There is a patch for this, but it may require Unicodification.
e50bb9a1 573
722d2a37 574=head2 Compile to real threaded code
3958b146 575
722d2a37 576=head2 Structured types
3958b146 577
722d2a37 578=head2 Modifiable $1 et al.
e50bb9a1 579
722d2a37 580 ($x = "elephant") =~ /e(ph)/;
581 $1 = "g"; # $x = "elegant"
e50bb9a1 582
722d2a37 583What happens if there are multiple (nested?) brackets? What if the
584string changes between the match and the assignment?
e50bb9a1 585
722d2a37 586=head2 Procedural interfaces for IO::*, etc.
e50bb9a1 587
722d2a37 588Some core modules have been accused of being overly-OO. Adding
589procedural interfaces could demystify them.
e50bb9a1 590
722d2a37 591=head2 RPC modules
e50bb9a1 592
722d2a37 593=head2 Attach/detach debugger from running program
e50bb9a1 594
722d2a37 595With C<gdb>, you can attach the debugger to a running program if you
596pass the process ID. It would be good to do this with the Perl debugger
597on a running Perl program, although I'm not sure how it would be done.
e50bb9a1 598
722d2a37 599=head2 GUI::Native
e50bb9a1 600
722d2a37 601A non-core module that would use "native" GUI to create graphical
602applications.
e50bb9a1 603
722d2a37 604=head2 foreach(reverse ...)
e50bb9a1 605
722d2a37 606Currently
e50bb9a1 607
722d2a37 608 foreach (reverse @_) { ... }
e50bb9a1 609
722d2a37 610puts C<@_> on the stack, reverses it putting the reversed version on the
611stack, then iterates forwards. Instead, it could be special-cased to put
612C<@_> on the stack then iterate backwards.
e50bb9a1 613
722d2a37 614=head2 Constant function cache
e50bb9a1 615
722d2a37 616=head2 Approximate regular expression matching
e50bb9a1 617
722d2a37 618=head1 Ongoing
e50bb9a1 619
722d2a37 620These items B<always> need doing:
e50bb9a1 621
722d2a37 622=head2 Update guts documentation
e50bb9a1 623
722d2a37 624Simon Cozens tries to do this when possible, and contributions to the
625C<perlapi> documentation is welcome.
e50bb9a1 626
722d2a37 627=head2 Add more tests
e50bb9a1 628
722d2a37 629Michael Schwern will donate $500 to Yet Another Society when all core
630modules have tests.
e50bb9a1 631
722d2a37 632=head2 Update auxiliary tools
e50bb9a1 633
722d2a37 634The code we ship with Perl should look like good Perl 5.
e50bb9a1 635
1e278fd9 636=head2 Create debugging macros
637
638Debugging macros (like printsv, dump) can make debugging perl inside a
639C debugger much easier. A good set for gdb comes with mod_perl.
640Something similar should be distributed with perl.
641
642The proper way to do this is to use and extend Devel::DebugInit.
643Devel::DebugInit also needs to be extended to support threads.
644
645See p5p archives for late May/early June 2001 for a recent discussion
646on this topic.
647
648=head2 truncate to the people
649
650One can emulate ftruncate() using F_FREESP and F_CHSIZ fcntls
651(see the UNIX FAQ for details). This needs to go somewhere near
652pp_sys.c:pp_truncate().
653
654One can emulate truncate() easily if one has ftruncate().
655This emulation should also go near pp_sys.pp_truncate().
656
657=head2 Unicode in Filenames
658
659chdir, chmod, chown, chroot, exec, glob, link, lstat, mkdir, open, qx,
660readdir, readlink, rename, rmdir, stat, symlink, sysopen, system,
661truncate, unlink, utime. All these could potentially accept Unicode
662filenames either as input or output (and in the case of system and qx
663Unicode in general, as input or output to/from the shell). Whether a
664filesystem - an operating system pair understands Unicode in filenames
665varies.
666
667Known combinations that have some level of understanding include
668Microsoft NTFS, Apple HFS+ (In Mac OS 9 and X) and Apple UFS (in Mac
669OS X), NFS v4 is rumored to be Unicode, and of course Plan 9. How to
670create Unicode filenames, what forms of Unicode are accepted and used
671(UCS-2, UTF-16, UTF-8), what (if any) is the normalization form used,
672and so on, varies. Finding the right level of interfacing to Perl
673requires some thought. Remember that an OS does not implicate a
674filesystem.
675
eb450546 676Note that in Windows the -C command line flag already does quite
677a bit of the above (but even there the support is not complete:
678for example the exec/spawn are not Unicode-aware) by turning on
679the so-called "wide API support".
680
722d2a37 681=head1 Recently done things
e50bb9a1 682
722d2a37 683These are things which have been on the todo lists in previous releases
684but have recently been completed.
e50bb9a1 685
b0b7f283 686=head2 Alternative RE syntax module
687
688The C<Regexp::English> module, available from the CPAN, provides this:
689
690 my $re = Regexp::English
691 -> start_of_line
692 -> literal('Flippers')
693 -> literal(':')
694 -> optional
695 -> whitespace_char
696 -> end
697 -> remember
698 -> multiple
699 -> digit;
700
701 /$re/;
702
722d2a37 703=head2 Safe signal handling
e50bb9a1 704
722d2a37 705A new signal model went into 5.7.1 without much fanfare. Operations and
706C<malloc>s are no longer interrupted by signals, which are handled
707between opcodes. This means that C<PERL_ASYNC_CHECK> now actually does
708something. However, there are still a few things that need to be done.
e50bb9a1 709
722d2a37 710=head2 Tie Modules
e50bb9a1 711
722d2a37 712Modules which implement arrays in terms of strings, substrings or files
713can be found on the CPAN.
e50bb9a1 714
722d2a37 715=head2 gettimeofday
e50bb9a1 716
210b36aa 717C<Time::HiRes> has been integrated into the core.
e50bb9a1 718
722d2a37 719=head2 setitimer and getimiter
e50bb9a1 720
210b36aa 721Adding C<Time::HiRes> got us this too.
e50bb9a1 722
722d2a37 723=head2 Testing __DIE__ hook
724
725Tests have been added.
726
727=head2 CPP equivalent in Perl
e50bb9a1 728
722d2a37 729A C Yardley will probably have done this by the time you can read this.
730This allows for a generalization of the C constant detection used in
731building C<Errno.pm>.
e50bb9a1 732
722d2a37 733=head2 Explicit switch statements
e50bb9a1 734
722d2a37 735C<Switch.pm> has been integrated into the core to give you all manner of
736C<switch...case> semantics.
e50bb9a1 737
722d2a37 738=head2 autocroak
e50bb9a1 739
722d2a37 740This is C<Fatal.pm>.
e50bb9a1 741
722d2a37 742=head2 UTF/EBCDIC
e50bb9a1 743
722d2a37 744Nick Ing-Simmons has made UTF-EBCDIC (UTR13) work with Perl.
e50bb9a1 745
722d2a37 746 EBCDIC? http://www.unicode.org/unicode/reports/tr16/
e50bb9a1 747
722d2a37 748=head2 UTF Regexes
e50bb9a1 749
722d2a37 750Although there are probably some small bugs to be rooted out, Jarkko
751Hietaniemi has made regular expressions polymorphic between bytes and
752characters.
e50bb9a1 753
722d2a37 754=head2 perlcc to produce executable
e50bb9a1 755
722d2a37 756C<perlcc> was recently rewritten, and can now produce standalone
757executables.
e50bb9a1 758
722d2a37 759=head2 END blocks saved in compiled output
e50bb9a1 760
722d2a37 761=head2 Secure temporary file module
e50bb9a1 762
722d2a37 763Tim Jenness' C<File::Temp> is now in core.
e50bb9a1 764
722d2a37 765=head2 Integrate Time::HiRes
e50bb9a1 766
722d2a37 767This module is now part of core.
e50bb9a1 768
722d2a37 769=head2 Turn Cwd into XS
e50bb9a1 770
722d2a37 771Benjamin Sugars has done this.
e50bb9a1 772
722d2a37 773=head2 Mmap for input
e50bb9a1 774
722d2a37 775Nick Ing-Simmons' C<perlio> supports an C<mmap> IO method.
e50bb9a1 776
722d2a37 777=head2 Byte to/from UTF8 and UTF8 to/from local conversion
e50bb9a1 778
722d2a37 779C<Encode> provides this.
e50bb9a1 780
722d2a37 781=head2 Add sockatmark support
e50bb9a1 782
722d2a37 783Added in 5.7.1
e50bb9a1 784
722d2a37 785=head2 Mailing list archives
786
f224927c 787http://lists.perl.org/ , http://archive.develooper.com/
722d2a37 788
789=head2 Bug tracking
790
791Richard Foley has written the bug tracking system at http://bugs.perl.org/
e50bb9a1 792
722d2a37 793=head2 Integrate MacPerl
e50bb9a1 794
722d2a37 795Chris Nandor and Matthias Neeracher have integrated the MacPerl changes
796into 5.6.0.
e50bb9a1 797
722d2a37 798=head2 Web "nerve center" for Perl
e50bb9a1 799
722d2a37 800http://use.perl.org/ is what you're looking for.
e50bb9a1 801
722d2a37 802=head2 Regular expression tutorial
e50bb9a1 803
722d2a37 804C<perlretut>, provided by Mark Kvale.
e50bb9a1 805
722d2a37 806=head2 Debugging Tutorial
e50bb9a1 807
722d2a37 808C<perldebtut>, written by Richard Foley.
e50bb9a1 809
722d2a37 810=head2 Integrate new modules
e50bb9a1 811
722d2a37 812Jarkko has been integrating madly into 5.7.x
e50bb9a1 813
722d2a37 814=head2 Integrate profiler
e50bb9a1 815
722d2a37 816C<Devel::DProf> is now a core module.
e50bb9a1 817
722d2a37 818=head2 Y2K error detection
e50bb9a1 819
722d2a37 820There's a configure option to detect unsafe concatenation with "19", and
821a CPAN module. (C<D'oh::Year>)
e50bb9a1 822
722d2a37 823=head2 Regular expression debugger
e50bb9a1 824
722d2a37 825While not part of core, Mark-Jason Dominus has written C<Rx> and has
826also come up with a generalised strategy for regular expression
827debugging.
e50bb9a1 828
722d2a37 829=head2 POD checker
e50bb9a1 830
722d2a37 831That's, uh, F<podchecker>
e50bb9a1 832
722d2a37 833=head2 "Dynamic" lexicals
e50bb9a1 834
722d2a37 835=head2 Cache precompiled modules
e50bb9a1 836
722d2a37 837=head1 Deprecated Wishes
e50bb9a1 838
722d2a37 839These are items which used to be in the todo file, but have been
840deprecated for some reason.
e50bb9a1 841
722d2a37 842=head2 Loop control on do{}
e50bb9a1 843
722d2a37 844This would break old code; use C<do{{ }}> instead.
e50bb9a1 845
722d2a37 846=head2 Lexically scoped typeglobs
e50bb9a1 847
722d2a37 848Not needed now we have lexical IO handles.
e50bb9a1 849
722d2a37 850=head2 format BOTTOM
3958b146 851
722d2a37 852=head2 report HANDLE
e50bb9a1 853
722d2a37 854Damian Conway's text formatting modules seem to be the Way To Go.
e50bb9a1 855
722d2a37 856=head2 Generalised want()/caller())
3958b146 857
638ae6a9 858Robin Houston's C<Want> module does this.
859
722d2a37 860=head2 Named prototypes
e50bb9a1 861
638ae6a9 862This seems to be delayed until Perl 6.
e50bb9a1 863
722d2a37 864=head2 Built-in globbing
e50bb9a1 865
722d2a37 866The C<File::Glob> module has been used to replace the C<glob> function.
e50bb9a1 867
722d2a37 868=head2 Regression tests for suidperl
e50bb9a1 869
722d2a37 870C<suidperl> is deprecated in favour of common sense.
e50bb9a1 871
722d2a37 872=head2 Cached hash values
e50bb9a1 873
722d2a37 874We have shared hash keys, which perform the same job.
e50bb9a1 875
722d2a37 876=head2 Add compression modules
e50bb9a1 877
722d2a37 878The compression modules are a little heavy; meanwhile, Nick Clark is
879working on experimental pragmata to do transparent decompression on
880input.
e50bb9a1 881
722d2a37 882=head2 Reorganise documentation into tutorials/references
e50bb9a1 883
722d2a37 884Could not get consensus on P5P about this.
e50bb9a1 885
722d2a37 886=head2 Remove distinction between functions and operators
887
888Caution: highly flammable.
889
890=head2 Make XS easier to use
e50bb9a1 891
722d2a37 892Use C<Inline> instead, or SWIG.
e50bb9a1 893
722d2a37 894=head2 Make embedding easier to use
e50bb9a1 895
722d2a37 896Use C<Inline::CPR>.
e50bb9a1 897
722d2a37 898=head2 man for perl
04c70446 899
1577cd80 900See the Perl Power Tools. ( http://language.perl.com/ppt/ )
04c70446 901
722d2a37 902=head2 my $Package::variable
04c70446 903
722d2a37 904Use C<our> instead.
04c70446 905
722d2a37 906=head2 "or" tests defined, not truth
04c70446 907
722d2a37 908Suggesting this on P5P B<will> cause a boring and interminable flamewar.
04c70446 909
722d2a37 910=head2 "class"-based lexicals
04c70446 911
cbb3fa72 912Use flyweight objects, secure hashes or, dare I say it, pseudo-hashes instead.
f86a8bc5 913(Or whatever will replace pseudohashes in 5.10.)
04c70446 914
722d2a37 915=head2 byteperl
04c70446 916
722d2a37 917C<ByteLoader> covers this.
04c70446 918
722d2a37 919=head2 Lazy evaluation / tail recursion removal
04c70446 920
f86a8bc5 921C<List::Util> gives first() (a short-circuiting grep); tail recursion
922removal is done manually, with C<goto &whoami;>. (However, MJD has
923found that C<goto &whoami> introduces a performance penalty, so maybe
924there should be a way to do this after all: C<sub foo {START: ... goto
925START;> is better.)
0562c0e3 926
927=head2 Make "use utf8" the default
928
f86a8bc5 929Because of backward compatibility this is difficult: scripts could not
930contain B<any legacy eight-bit data> (like Latin-1) anymore, even in
931string literals or pod. Also would introduce a measurable slowdown of
932at least few percentages since all regular expression operations would
933be done in full UTF-8. But if you want to try this, add
934-DUSE_UTF8_SCRIPTS to your compilation flags.
935
3298bd4d 936=head2 Unicode collation and normalization
937
938The Unicode::Collate and Unicode::Normalize modules
939by SADAHIRO Tomoyuki have been included since 5.8.0.
940
941 Collation? http://www.unicode.org/unicode/reports/tr10/
942 Normalization? http://www.unicode.org/unicode/reports/tr15/
0562c0e3 943
1626a787 944=head2 pack/unpack tutorial
945
946Wolfgang Laun finished what Simon Cozens started.
947
3298bd4d 948=cut