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TODO: yada yada yada
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1=head1 NAME
2
3perltodo - Perl TO-DO List
4
5=head1 DESCRIPTION
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7This is a list of wishes for Perl. The tasks we think are smaller or easier
8are listed first. Anyone is welcome to work on any of these, but it's a good
9idea to first contact I<perl5-porters@perl.org> to avoid duplication of
10effort. By all means contact a pumpking privately first if you prefer.
e50bb9a1 11
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12Whilst patches to make the list shorter are most welcome, ideas to add to
13the list are also encouraged. Check the perl5-porters archives for past
14ideas, and any discussion about them. One set of archives may be found at:
e50bb9a1 15
0bdfc961 16 http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/
938c8732 17
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18What can we offer you in return? Fame, fortune, and everlasting glory? Maybe
19not, but if your patch is incorporated, then we'll add your name to the
20F<AUTHORS> file, which ships in the official distribution. How many other
21programming languages offer you 1 line of immortality?
938c8732 22
4e577f8b 23=head1 The roadmap to 5.10
938c8732 24
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25The roadmap to 5.10 envisages feature based releases, as various items in this
26TODO are completed.
27
256ddcd0
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28=head2 Needed for the final 5.10.0 release
29
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30Review perlguts. Significant changes have occured since 5.8, and we can't
31release a new version without making sure these are covered.
32
0bdfc961 33=head1 Tasks that only need Perl knowledge
e50bb9a1 34
0bdfc961 35=head2 common test code for timed bail out
e50bb9a1 36
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37Write portable self destruct code for tests to stop them burning CPU in
38infinite loops. This needs to avoid using alarm, as some of the tests are
39testing alarm/sleep or timers.
e50bb9a1 40
0bdfc961 41=head2 POD -> HTML conversion in the core still sucks
e50bb9a1 42
938c8732 43Which is crazy given just how simple POD purports to be, and how simple HTML
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44can be. It's not actually I<as> simple as it sounds, particularly with the
45flexibility POD allows for C<=item>, but it would be good to improve the
46visual appeal of the HTML generated, and to avoid it having any validation
47errors. See also L</make HTML install work>, as the layout of installation tree
48is needed to improve the cross-linking.
938c8732 49
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50The addition of C<Pod::Simple> and its related modules may make this task
51easier to complete.
52
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53=head2 Parallel testing
54
b2e2905c 55(This probably impacts much more than the core: also the Test::Harness
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56and TAP::* modules on CPAN.)
57
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58The core regression test suite is getting ever more comprehensive, which has
59the side effect that it takes longer to run. This isn't so good. Investigate
60whether it would be feasible to give the harness script the B<option> of
61running sets of tests in parallel. This would be useful for tests in
62F<t/op/*.t> and F<t/uni/*.t> and maybe some sets of tests in F<lib/>.
63
64Questions to answer
65
66=over 4
67
68=item 1
69
70How does screen layout work when you're running more than one test?
71
72=item 2
73
74How does the caller of test specify how many tests to run in parallel?
75
76=item 3
77
78How do setup/teardown tests identify themselves?
79
80=back
81
82Pugs already does parallel testing - can their approach be re-used?
83
0bdfc961 84=head2 Make Schwern poorer
e50bb9a1 85
613bd4f7 86We should have tests for everything. When all the core's modules are tested,
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87Schwern has promised to donate to $500 to TPF. We may need volunteers to
88hold him upside down and shake vigorously in order to actually extract the
89cash.
3958b146 90
0bdfc961 91=head2 Improve the coverage of the core tests
e50bb9a1 92
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93Use Devel::Cover to ascertain the core modules's test coverage, then add
94tests that are currently missing.
30222c0f 95
0bdfc961 96=head2 test B
e50bb9a1 97
0bdfc961 98A full test suite for the B module would be nice.
e50bb9a1 99
0bdfc961 100=head2 A decent benchmark
e50bb9a1 101
617eabfa 102C<perlbench> seems impervious to any recent changes made to the perl core. It
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103would be useful to have a reasonable general benchmarking suite that roughly
104represented what current perl programs do, and measurably reported whether
105tweaks to the core improve, degrade or don't really affect performance, to
106guide people attempting to optimise the guts of perl. Gisle would welcome
107new tests for perlbench.
6168cf99 108
0bdfc961 109=head2 fix tainting bugs
6168cf99 110
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111Fix the bugs revealed by running the test suite with the C<-t> switch (via
112C<make test.taintwarn>).
e50bb9a1 113
0bdfc961 114=head2 Dual life everything
e50bb9a1 115
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116As part of the "dists" plan, anything that doesn't belong in the smallest perl
117distribution needs to be dual lifed. Anything else can be too. Figure out what
118changes would be needed to package that module and its tests up for CPAN, and
119do so. Test it with older perl releases, and fix the problems you find.
e50bb9a1 120
0bdfc961 121=head2 Improving C<threads::shared>
722d2a37 122
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123Investigate whether C<threads::shared> could share aggregates properly with
124only Perl level changes to shared.pm
722d2a37 125
0bdfc961 126=head2 POSIX memory footprint
e50bb9a1 127
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128Ilya observed that use POSIX; eats memory like there's no tomorrow, and at
129various times worked to cut it down. There is probably still fat to cut out -
130for example POSIX passes Exporter some very memory hungry data structures.
e50bb9a1 131
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132=head2 embed.pl/makedef.pl
133
134There is a script F<embed.pl> that generates several header files to prefix
135all of Perl's symbols in a consistent way, to provide some semblance of
136namespace support in C<C>. Functions are declared in F<embed.fnc>, variables
137in F<interpvar.h> and F<thrdvar.h>. Quite a few of the functions and variables
138are conditionally declared there, using C<#ifdef>. However, F<embed.pl>
139doesn't understand the C macros, so the rules about which symbols are present
140when is duplicated in F<makedef.pl>. Writing things twice is bad, m'kay.
141It would be good to teach C<embed.pl> to understand the conditional
142compilation, and hence remove the duplication, and the mistakes it has caused.
e50bb9a1 143
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144=head2 use strict; and AutoLoad
145
146Currently if you write
147
148 package Whack;
149 use AutoLoader 'AUTOLOAD';
150 use strict;
151 1;
152 __END__
153 sub bloop {
154 print join (' ', No, strict, here), "!\n";
155 }
156
157then C<use strict;> isn't in force within the autoloaded subroutines. It would
158be more consistent (and less surprising) to arrange for all lexical pragmas
159in force at the __END__ block to be in force within each autoloaded subroutine.
160
0bdfc961 161=head1 Tasks that need a little sysadmin-type knowledge
e50bb9a1 162
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163Or if you prefer, tasks that you would learn from, and broaden your skills
164base...
e50bb9a1 165
cd793d32 166=head2 make HTML install work
e50bb9a1 167
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168There is an C<installhtml> target in the Makefile. It's marked as
169"experimental". It would be good to get this tested, make it work reliably, and
170remove the "experimental" tag. This would include
171
172=over 4
173
174=item 1
175
176Checking that cross linking between various parts of the documentation works.
177In particular that links work between the modules (files with POD in F<lib/>)
178and the core documentation (files in F<pod/>)
179
180=item 2
181
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182Work out how to split C<perlfunc> into chunks, preferably one per function
183group, preferably with general case code that could be used elsewhere.
184Challenges here are correctly identifying the groups of functions that go
185together, and making the right named external cross-links point to the right
186page. Things to be aware of are C<-X>, groups such as C<getpwnam> to
187C<endservent>, two or more C<=items> giving the different parameter lists, such
188as
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189
190 =item substr EXPR,OFFSET,LENGTH,REPLACEMENT
adebf063 191 =item substr EXPR,OFFSET,LENGTH
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192 =item substr EXPR,OFFSET
193
194and different parameter lists having different meanings. (eg C<select>)
195
196=back
3a89a73c 197
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198=head2 compressed man pages
199
200Be able to install them. This would probably need a configure test to see how
201the system does compressed man pages (same directory/different directory?
202same filename/different filename), as well as tweaking the F<installman> script
203to compress as necessary.
204
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205=head2 Add a code coverage target to the Makefile
206
207Make it easy for anyone to run Devel::Cover on the core's tests. The steps
208to do this manually are roughly
209
210=over 4
211
212=item *
213
214do a normal C<Configure>, but include Devel::Cover as a module to install
215(see F<INSTALL> for how to do this)
216
217=item *
218
219 make perl
220
221=item *
222
223 cd t; HARNESS_PERL_SWITCHES=-MDevel::Cover ./perl -I../lib harness
224
225=item *
226
227Process the resulting Devel::Cover database
228
229=back
230
231This just give you the coverage of the F<.pm>s. To also get the C level
232coverage you need to
233
234=over 4
235
236=item *
237
238Additionally tell C<Configure> to use the appropriate C compiler flags for
239C<gcov>
240
241=item *
242
243 make perl.gcov
244
245(instead of C<make perl>)
246
247=item *
248
249After running the tests run C<gcov> to generate all the F<.gcov> files.
250(Including down in the subdirectories of F<ext/>
251
252=item *
253
254(From the top level perl directory) run C<gcov2perl> on all the C<.gcov> files
255to get their stats into the cover_db directory.
256
257=item *
258
259Then process the Devel::Cover database
260
261=back
262
263It would be good to add a single switch to C<Configure> to specify that you
264wanted to perform perl level coverage, and another to specify C level
265coverage, and have C<Configure> and the F<Makefile> do all the right things
266automatically.
267
02f21748 268=head2 Make Config.pm cope with differences between built and installed perl
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269
270Quite often vendors ship a perl binary compiled with their (pay-for)
271compilers. People install a free compiler, such as gcc. To work out how to
272build extensions, Perl interrogates C<%Config>, so in this situation
273C<%Config> describes compilers that aren't there, and extension building
274fails. This forces people into choosing between re-compiling perl themselves
275using the compiler they have, or only using modules that the vendor ships.
276
277It would be good to find a way teach C<Config.pm> about the installation setup,
278possibly involving probing at install time or later, so that the C<%Config> in
279a binary distribution better describes the installed machine, when the
280installed machine differs from the build machine in some significant way.
281
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282=head2 linker specification files
283
284Some platforms mandate that you provide a list of a shared library's external
285symbols to the linker, so the core already has the infrastructure in place to
286do this for generating shared perl libraries. My understanding is that the
287GNU toolchain can accept an optional linker specification file, and restrict
288visibility just to symbols declared in that file. It would be good to extend
289F<makedef.pl> to support this format, and to provide a means within
290C<Configure> to enable it. This would allow Unix users to test that the
291export list is correct, and to build a perl that does not pollute the global
292namespace with private symbols.
293
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294=head2 Cross-compile support
295
296Currently C<Configure> understands C<-Dusecrosscompile> option. This option
297arranges for building C<miniperl> for TARGET machine, so this C<miniperl> is
298assumed then to be copied to TARGET machine and used as a replacement of full
299C<perl> executable.
300
d1307786 301This could be done little differently. Namely C<miniperl> should be built for
a229ae3b 302HOST and then full C<perl> with extensions should be compiled for TARGET.
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303This, however, might require extra trickery for %Config: we have one config
304first for HOST and then another for TARGET.
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305
306=head1 Tasks that need a little C knowledge
307
308These tasks would need a little C knowledge, but don't need any specific
309background or experience with XS, or how the Perl interpreter works
310
311=head2 Make it clear from -v if this is the exact official release
89007cb3 312
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313Currently perl from C<p4>/C<rsync> ships with a F<patchlevel.h> file that
314usually defines one local patch, of the form "MAINT12345" or "RC1". The output
315of perl -v doesn't report that a perl isn't an official release, and this
89007cb3 316information can get lost in bugs reports. Because of this, the minor version
fa11829f 317isn't bumped up until RC time, to minimise the possibility of versions of perl
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318escaping that believe themselves to be newer than they actually are.
319
320It would be useful to find an elegant way to have the "this is an interim
321maintenance release" or "this is a release candidate" in the terse -v output,
322and have it so that it's easy for the pumpking to remove this just as the
323release tarball is rolled up. This way the version pulled out of rsync would
324always say "I'm a development release" and it would be safe to bump the
325reported minor version as soon as a release ships, which would aid perl
326developers.
327
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328This task is really about thinking of an elegant way to arrange the C source
329such that it's trivial for the Pumpking to flag "this is an official release"
330when making a tarball, yet leave the default source saying "I'm not the
331official release".
332
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333=head2 Ordering of "global" variables.
334
335F<thrdvar.h> and F<intrpvarh> define the "global" variables that need to be
336per-thread under ithreads, where the variables are actually elements in a
337structure. As C dictates, the variables must be laid out in order of
338declaration. There is a comment
339C</* Important ones in the first cache line (if alignment is done right) */>
340which implies that at some point in the past the ordering was carefully chosen
341(at least in part). However, it's clear that the ordering is less than perfect,
342as currently there are things such as 7 C<bool>s in a row, then something
343typically requiring 4 byte alignment, and then an odd C<bool> later on.
344(C<bool>s are typically defined as C<char>s). So it would be good for someone
345to review the ordering of the variables, to see how much alignment padding can
346be removed.
347
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348It's also worth checking that all variables are actually used. Perl 5.8.0
349shipped with C<PL_nrs> still defined in F<thrdvar.h>, despite it being unused
350since a change over a year earlier. Had this been spotted before release, it
351could have been removed, but now it has to remain in the 5.8.x releases to
352keep the structure the same size, to retain binary compatibility.
353
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354It's probably worth checking if all need to be the types they are. For example
355
356 PERLVAR(Ierror_count, I32) /* how many errors so far, max 10 */
357
358might work as well if stored in a signed (or unsigned) 8 bit value, if the
359comment is accurate. C<PL_multi_open> and C<PL_multi_close> can probably
360become C<char>s. Finding variables to downsize coupled with rearrangement
361could shrink the interpreter structure; a size saving which is multiplied by
362the number of threads running.
363
fee0a0f7 364=head2 Profile Perl - am I hot or not?
62403a3c 365
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366The Perl source code is stable enough that it makes sense to profile it,
367identify and optimise the hotspots. It would be good to measure the
368performance of the Perl interpreter using free tools such as cachegrind,
369gprof, and dtrace, and work to reduce the bottlenecks they reveal.
370
371As part of this, the idea of F<pp_hot.c> is that it contains the I<hot> ops,
372the ops that are most commonly used. The idea is that by grouping them, their
373object code will be adjacent in the executable, so they have a greater chance
374of already being in the CPU cache (or swapped in) due to being near another op
375already in use.
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376
377Except that it's not clear if these really are the most commonly used ops. So
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378as part of exercising your skills with coverage and profiling tools you might
379want to determine what ops I<really> are the most commonly used. And in turn
380suggest evictions and promotions to achieve a better F<pp_hot.c>.
62403a3c 381
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382=head2 Allocate OPs from arenas
383
384Currently all new OP structures are individually malloc()ed and free()d.
385All C<malloc> implementations have space overheads, and are now as fast as
386custom allocates so it would both use less memory and less CPU to allocate
387the various OP structures from arenas. The SV arena code can probably be
388re-used for this.
389
a229ae3b 390=head2 Improve win32/wince.c
0bdfc961 391
a229ae3b 392Currently, numerous functions look virtually, if not completely,
02f21748 393identical in both C<win32/wince.c> and C<win32/win32.c> files, which can't
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394be good.
395
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396=head2 Use secure CRT functions when building with VC8 on Win32
397
398Visual C++ 2005 (VC++ 8.x) deprecated a number of CRT functions on the basis
399that they were "unsafe" and introduced differently named secure versions of
400them as replacements, e.g. instead of writing
401
402 FILE* f = fopen(__FILE__, "r");
403
404one should now write
405
406 FILE* f;
407 errno_t err = fopen_s(&f, __FILE__, "r");
408
409Currently, the warnings about these deprecations have been disabled by adding
410-D_CRT_SECURE_NO_DEPRECATE to the CFLAGS. It would be nice to remove that
411warning suppressant and actually make use of the new secure CRT functions.
412
413There is also a similar issue with POSIX CRT function names like fileno having
414been deprecated in favour of ISO C++ conformant names like _fileno. These
415warnings are also currently suppressed with the compiler option /wd4996. It
416might be nice to do as Microsoft suggest here too, although, unlike the secure
417functions issue, there is presumably little or no benefit in this case.
418
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419=head1 Tasks that need a knowledge of XS
420
421These tasks would need C knowledge, and roughly the level of knowledge of
422the perl API that comes from writing modules that use XS to interface to
423C.
424
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425=head2 autovivification
426
427Make all autovivification consistent w.r.t LVALUE/RVALUE and strict/no strict;
428
429This task is incremental - even a little bit of work on it will help.
430
431=head2 Unicode in Filenames
432
433chdir, chmod, chown, chroot, exec, glob, link, lstat, mkdir, open,
434opendir, qx, readdir, readlink, rename, rmdir, stat, symlink, sysopen,
435system, truncate, unlink, utime, -X. All these could potentially accept
436Unicode filenames either as input or output (and in the case of system
437and qx Unicode in general, as input or output to/from the shell).
438Whether a filesystem - an operating system pair understands Unicode in
439filenames varies.
440
441Known combinations that have some level of understanding include
442Microsoft NTFS, Apple HFS+ (In Mac OS 9 and X) and Apple UFS (in Mac
443OS X), NFS v4 is rumored to be Unicode, and of course Plan 9. How to
444create Unicode filenames, what forms of Unicode are accepted and used
445(UCS-2, UTF-16, UTF-8), what (if any) is the normalization form used,
446and so on, varies. Finding the right level of interfacing to Perl
447requires some thought. Remember that an OS does not implicate a
448filesystem.
449
450(The Windows -C command flag "wide API support" has been at least
451temporarily retired in 5.8.1, and the -C has been repurposed, see
452L<perlrun>.)
453
454=head2 Unicode in %ENV
455
456Currently the %ENV entries are always byte strings.
457
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458=head2 Unicode and glob()
459
460Currently glob patterns and filenames returned from File::Glob::glob()
461are always byte strings.
462
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463=head2 use less 'memory'
464
465Investigate trade offs to switch out perl's choices on memory usage.
466Particularly perl should be able to give memory back.
467
468This task is incremental - even a little bit of work on it will help.
469
470=head2 Re-implement C<:unique> in a way that is actually thread-safe
471
472The old implementation made bad assumptions on several levels. A good 90%
473solution might be just to make C<:unique> work to share the string buffer
474of SvPVs. That way large constant strings can be shared between ithreads,
475such as the configuration information in F<Config>.
476
477=head2 Make tainting consistent
478
479Tainting would be easier to use if it didn't take documented shortcuts and
480allow taint to "leak" everywhere within an expression.
481
482=head2 readpipe(LIST)
483
484system() accepts a LIST syntax (and a PROGRAM LIST syntax) to avoid
485running a shell. readpipe() (the function behind qx//) could be similarly
486extended.
487
488=head2 strcat(), strcpy(), strncat(), strncpy(), sprintf(), vsprintf()
489
490Maybe create a utility that checks after each libperl.a creation that
491none of the above (nor sprintf(), vsprintf(), or *SHUDDER* gets())
492ever creep back to libperl.a.
493
494 nm libperl.a | ./miniperl -alne '$o = $F[0] if /:$/; print "$o $F[1]" if $F[0] eq "U" && $F[1] =~ /^(?:strn?c(?:at|py)|v?sprintf|gets)$/'
495
496Note, of course, that this will only tell whether B<your> platform
497is using those naughty interfaces.
498
499=head2 Audit the code for destruction ordering assumptions
500
501Change 25773 notes
502
503 /* Need to check SvMAGICAL, as during global destruction it may be that
504 AvARYLEN(av) has been freed before av, and hence the SvANY() pointer
505 is now part of the linked list of SV heads, rather than pointing to
506 the original body. */
507 /* FIXME - audit the code for other bugs like this one. */
508
509adding the C<SvMAGICAL> check to
510
511 if (AvARYLEN(av) && SvMAGICAL(AvARYLEN(av))) {
512 MAGIC *mg = mg_find (AvARYLEN(av), PERL_MAGIC_arylen);
513
514Go through the core and look for similar assumptions that SVs have particular
515types, as all bets are off during global destruction.
516
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517=head2 Extend PerlIO and PerlIO::Scalar
518
519PerlIO::Scalar doesn't know how to truncate(). Implementing this
520would require extending the PerlIO vtable.
521
522Similarly the PerlIO vtable doesn't know about formats (write()), or
523about stat(), or chmod()/chown(), utime(), or flock().
524
525(For PerlIO::Scalar it's hard to see what e.g. mode bits or ownership
526would mean.)
527
528PerlIO doesn't do directories or symlinks, either: mkdir(), rmdir(),
529opendir(), closedir(), seekdir(), rewinddir(), glob(); symlink(),
530readlink().
531
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532=head2 -C on the #! line
533
534It should be possible to make -C work correctly if found on the #! line,
535given that all perl command line options are strict ASCII, and -C changes
536only the interpretation of non-ASCII characters, and not for the script file
537handle. To make it work needs some investigation of the ordering of function
538calls during startup, and (by implication) a bit of tweaking of that order.
539
540
0bdfc961 541=head1 Tasks that need a knowledge of the interpreter
3298bd4d 542
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543These tasks would need C knowledge, and knowledge of how the interpreter works,
544or a willingness to learn.
3298bd4d 545
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546=head2 Implement $value ~~ 0 .. $range
547
548It would be nice to extend the syntax of the C<~~> operator to also
549understand numeric (and maybe alphanumeric) ranges.
550
d10fc472 551=head2 Attach/detach debugger from running program
1626a787 552
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553The old perltodo notes "With C<gdb>, you can attach the debugger to a running
554program if you pass the process ID. It would be good to do this with the Perl
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555debugger on a running Perl program, although I'm not sure how it would be
556done." ssh and screen do this with named pipes in /tmp. Maybe we can too.
1626a787 557
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558=head2 LVALUE functions for lists
559
560The old perltodo notes that lvalue functions don't work for list or hash
561slices. This would be good to fix.
562
563=head2 LVALUE functions in the debugger
564
565The old perltodo notes that lvalue functions don't work in the debugger. This
566would be good to fix.
567
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568=head2 regexp optimiser optional
569
570The regexp optimiser is not optional. It should configurable to be, to allow
571its performance to be measured, and its bugs to be easily demonstrated.
572
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573=head2 delete &function
574
575Allow to delete functions. One can already undef them, but they're still
576in the stash.
577
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578=head2 optional optimizer
579
580Make the peephole optimizer optional. Currently it performs two tasks as
581it walks the optree - genuine peephole optimisations, and necessary fixups of
582ops. It would be good to find an efficient way to switch out the
583optimisations whilst keeping the fixups.
584
585=head2 You WANT *how* many
586
587Currently contexts are void, scalar and list. split has a special mechanism in
588place to pass in the number of return values wanted. It would be useful to
589have a general mechanism for this, backwards compatible and little speed hit.
590This would allow proposals such as short circuiting sort to be implemented
591as a module on CPAN.
592
593=head2 lexical aliases
594
595Allow lexical aliases (maybe via the syntax C<my \$alias = \$foo>.
596
597=head2 entersub XS vs Perl
598
599At the moment pp_entersub is huge, and has code to deal with entering both
600perl and XS subroutines. Subroutine implementations rarely change between
601perl and XS at run time, so investigate using 2 ops to enter subs (one for
602XS, one for perl) and swap between if a sub is redefined.
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603
604=head2 Self ties
605
606self ties are currently illegal because they caused too many segfaults. Maybe
607the causes of these could be tracked down and self-ties on all types re-
608instated.
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609
610=head2 Optimize away @_
611
612The old perltodo notes "Look at the "reification" code in C<av.c>".
613
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614=head2 What hooks would assertions need?
615
616Assertions are in the core, and work. However, assertions needed to be added
617as a core patch, rather than an XS module in ext, or a CPAN module, because
618the core has no hooks in the necessary places. It would be useful to
619investigate what hooks would need to be added to make it possible to provide
620the full assertion support from a CPAN module, so that we aren't constraining
621the imagination of future CPAN authors.
622
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623=head2 Properly Unicode safe tokeniser and pads.
624
625The tokeniser isn't actually very UTF-8 clean. C<use utf8;> is a hack -
626variable names are stored in stashes as raw bytes, without the utf-8 flag
627set. The pad API only takes a C<char *> pointer, so that's all bytes too. The
628tokeniser ignores the UTF-8-ness of C<PL_rsfp>, or any SVs returned from
629source filters. All this could be fixed.
630
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RGS
631=head2 The yada yada yada operators
632
633Perl 6's Synopsis 3 says:
634
635I<The ... operator is the "yada, yada, yada" list operator, which is used as
636the body in function prototypes. It complains bitterly (by calling fail)
637if it is ever executed. Variant ??? calls warn, and !!! calls die.>
638
639Those would be nice to add to Perl 5. That could be done without new ops.
640
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641=head1 Big projects
642
643Tasks that will get your name mentioned in the description of the "Highlights
644of 5.10"
645
646=head2 make ithreads more robust
647
4e577f8b 648Generally make ithreads more robust. See also L</iCOW>
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649
650This task is incremental - even a little bit of work on it will help, and
651will be greatly appreciated.
652
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653One bit would be to write the missing code in sv.c:Perl_dirp_dup.
654
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655Fix Perl_sv_dup, et al so that threads can return objects.
656
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657=head2 iCOW
658
659Sarathy and Arthur have a proposal for an improved Copy On Write which
660specifically will be able to COW new ithreads. If this can be implemented
661it would be a good thing.
662
663=head2 (?{...}) closures in regexps
664
665Fix (or rewrite) the implementation of the C</(?{...})/> closures.
666
667=head2 A re-entrant regexp engine
668
669This will allow the use of a regex from inside (?{ }), (??{ }) and
670(?(?{ })|) constructs.
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672=head2 Add class set operations to regexp engine
673
674Apparently these are quite useful. Anyway, Jeffery Friedl wants them.
675
676demerphq has this on his todo list, but right at the bottom.