This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
IO::Compress::Base
[perl5.git] / pod / perltodo.pod
CommitLineData
7711098a
GS
1=head1 NAME
2
3perltodo - Perl TO-DO List
4
5=head1 DESCRIPTION
e50bb9a1 6
0bdfc961
NC
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
0bdfc961
NC
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
617eabfa
NC
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
4e577f8b
NC
25The roadmap to 5.10 envisages feature based releases, as various items in this
26TODO are completed.
27
4e577f8b
NC
28=head2 Needed for a 5.9.4 release
29
30=over
31
32=item *
78ef48ad
RGS
33
34Review assertions. Review syntax to combine assertions. Assertions could take
35advantage of the lexical pragmas work. L</What hooks would assertions need?>
4e577f8b 36
860f190d
RGS
37=item *
38
39C<encoding::warnings> should be turned into a lexical pragma.
0d720714 40C<encoding> should, too (probably).
860f190d 41
4e577f8b
NC
42=back
43
44=head2 Needed for a 5.9.5 release
45
46=over
47
48=item *
49Implement L</_ prototype character>
50
51=item *
52Implement L</state variables>
53
54=back
55
56=head2 Needed for a 5.9.6 release
57
58Stabilisation. If all goes well, this will be the equivalent of a 5.10-beta.
e50bb9a1 59
0bdfc961 60=head1 Tasks that only need Perl knowledge
e50bb9a1 61
0bdfc961 62=head2 common test code for timed bail out
e50bb9a1 63
0bdfc961
NC
64Write portable self destruct code for tests to stop them burning CPU in
65infinite loops. This needs to avoid using alarm, as some of the tests are
66testing alarm/sleep or timers.
e50bb9a1 67
0bdfc961 68=head2 POD -> HTML conversion in the core still sucks
e50bb9a1 69
938c8732 70Which is crazy given just how simple POD purports to be, and how simple HTML
adebf063
NC
71can be. It's not actually I<as> simple as it sounds, particularly with the
72flexibility POD allows for C<=item>, but it would be good to improve the
73visual appeal of the HTML generated, and to avoid it having any validation
74errors. See also L</make HTML install work>, as the layout of installation tree
75is needed to improve the cross-linking.
938c8732 76
dc0fb092
SP
77The addition of C<Pod::Simple> and its related modules may make this task
78easier to complete.
79
aa237293
NC
80=head2 Parallel testing
81
82The core regression test suite is getting ever more comprehensive, which has
83the side effect that it takes longer to run. This isn't so good. Investigate
84whether it would be feasible to give the harness script the B<option> of
85running sets of tests in parallel. This would be useful for tests in
86F<t/op/*.t> and F<t/uni/*.t> and maybe some sets of tests in F<lib/>.
87
88Questions to answer
89
90=over 4
91
92=item 1
93
94How does screen layout work when you're running more than one test?
95
96=item 2
97
98How does the caller of test specify how many tests to run in parallel?
99
100=item 3
101
102How do setup/teardown tests identify themselves?
103
104=back
105
106Pugs already does parallel testing - can their approach be re-used?
107
0bdfc961 108=head2 Make Schwern poorer
e50bb9a1 109
613bd4f7 110We should have tests for everything. When all the core's modules are tested,
0bdfc961
NC
111Schwern has promised to donate to $500 to TPF. We may need volunteers to
112hold him upside down and shake vigorously in order to actually extract the
113cash.
3958b146 114
0bdfc961 115See F<t/lib/1_compile.t> for the 3 remaining modules that need tests.
e50bb9a1 116
0bdfc961 117=head2 Improve the coverage of the core tests
e50bb9a1 118
0bdfc961
NC
119Use Devel::Cover to ascertain the core's test coverage, then add tests that
120are currently missing.
30222c0f 121
0bdfc961 122=head2 test B
e50bb9a1 123
0bdfc961 124A full test suite for the B module would be nice.
e50bb9a1 125
0bdfc961 126=head2 A decent benchmark
e50bb9a1 127
617eabfa 128C<perlbench> seems impervious to any recent changes made to the perl core. It
0bdfc961
NC
129would be useful to have a reasonable general benchmarking suite that roughly
130represented what current perl programs do, and measurably reported whether
131tweaks to the core improve, degrade or don't really affect performance, to
132guide people attempting to optimise the guts of perl. Gisle would welcome
133new tests for perlbench.
6168cf99 134
0bdfc961 135=head2 fix tainting bugs
6168cf99 136
0bdfc961
NC
137Fix the bugs revealed by running the test suite with the C<-t> switch (via
138C<make test.taintwarn>).
e50bb9a1 139
0bdfc961 140=head2 Dual life everything
e50bb9a1 141
0bdfc961
NC
142As part of the "dists" plan, anything that doesn't belong in the smallest perl
143distribution needs to be dual lifed. Anything else can be too. Figure out what
144changes would be needed to package that module and its tests up for CPAN, and
145do so. Test it with older perl releases, and fix the problems you find.
e50bb9a1 146
0bdfc961 147=head2 Improving C<threads::shared>
722d2a37 148
0bdfc961
NC
149Investigate whether C<threads::shared> could share aggregates properly with
150only Perl level changes to shared.pm
722d2a37 151
0bdfc961 152=head2 POSIX memory footprint
e50bb9a1 153
0bdfc961
NC
154Ilya observed that use POSIX; eats memory like there's no tomorrow, and at
155various times worked to cut it down. There is probably still fat to cut out -
156for example POSIX passes Exporter some very memory hungry data structures.
e50bb9a1 157
eed36644
NC
158=head2 embed.pl/makedef.pl
159
160There is a script F<embed.pl> that generates several header files to prefix
161all of Perl's symbols in a consistent way, to provide some semblance of
162namespace support in C<C>. Functions are declared in F<embed.fnc>, variables
163in F<interpvar.h> and F<thrdvar.h>. Quite a few of the functions and variables
164are conditionally declared there, using C<#ifdef>. However, F<embed.pl>
165doesn't understand the C macros, so the rules about which symbols are present
166when is duplicated in F<makedef.pl>. Writing things twice is bad, m'kay.
167It would be good to teach C<embed.pl> to understand the conditional
168compilation, and hence remove the duplication, and the mistakes it has caused.
e50bb9a1 169
e50bb9a1 170
e50bb9a1 171
e50bb9a1 172
adebf063 173
adebf063 174
0bdfc961 175=head1 Tasks that need a little sysadmin-type knowledge
e50bb9a1 176
0bdfc961
NC
177Or if you prefer, tasks that you would learn from, and broaden your skills
178base...
e50bb9a1 179
cd793d32 180=head2 make HTML install work
e50bb9a1 181
adebf063
NC
182There is an C<installhtml> target in the Makefile. It's marked as
183"experimental". It would be good to get this tested, make it work reliably, and
184remove the "experimental" tag. This would include
185
186=over 4
187
188=item 1
189
190Checking that cross linking between various parts of the documentation works.
191In particular that links work between the modules (files with POD in F<lib/>)
192and the core documentation (files in F<pod/>)
193
194=item 2
195
617eabfa
NC
196Work out how to split C<perlfunc> into chunks, preferably one per function
197group, preferably with general case code that could be used elsewhere.
198Challenges here are correctly identifying the groups of functions that go
199together, and making the right named external cross-links point to the right
200page. Things to be aware of are C<-X>, groups such as C<getpwnam> to
201C<endservent>, two or more C<=items> giving the different parameter lists, such
202as
adebf063
NC
203
204 =item substr EXPR,OFFSET,LENGTH,REPLACEMENT
adebf063 205 =item substr EXPR,OFFSET,LENGTH
adebf063
NC
206 =item substr EXPR,OFFSET
207
208and different parameter lists having different meanings. (eg C<select>)
209
210=back
3a89a73c 211
0bdfc961
NC
212=head2 compressed man pages
213
214Be able to install them. This would probably need a configure test to see how
215the system does compressed man pages (same directory/different directory?
216same filename/different filename), as well as tweaking the F<installman> script
217to compress as necessary.
218
30222c0f
NC
219=head2 Add a code coverage target to the Makefile
220
221Make it easy for anyone to run Devel::Cover on the core's tests. The steps
222to do this manually are roughly
223
224=over 4
225
226=item *
227
228do a normal C<Configure>, but include Devel::Cover as a module to install
229(see F<INSTALL> for how to do this)
230
231=item *
232
233 make perl
234
235=item *
236
237 cd t; HARNESS_PERL_SWITCHES=-MDevel::Cover ./perl -I../lib harness
238
239=item *
240
241Process the resulting Devel::Cover database
242
243=back
244
245This just give you the coverage of the F<.pm>s. To also get the C level
246coverage you need to
247
248=over 4
249
250=item *
251
252Additionally tell C<Configure> to use the appropriate C compiler flags for
253C<gcov>
254
255=item *
256
257 make perl.gcov
258
259(instead of C<make perl>)
260
261=item *
262
263After running the tests run C<gcov> to generate all the F<.gcov> files.
264(Including down in the subdirectories of F<ext/>
265
266=item *
267
268(From the top level perl directory) run C<gcov2perl> on all the C<.gcov> files
269to get their stats into the cover_db directory.
270
271=item *
272
273Then process the Devel::Cover database
274
275=back
276
277It would be good to add a single switch to C<Configure> to specify that you
278wanted to perform perl level coverage, and another to specify C level
279coverage, and have C<Configure> and the F<Makefile> do all the right things
280automatically.
281
0bdfc961
NC
282=head2 Make Config.pm cope with differences between build and installed perl
283
284Quite often vendors ship a perl binary compiled with their (pay-for)
285compilers. People install a free compiler, such as gcc. To work out how to
286build extensions, Perl interrogates C<%Config>, so in this situation
287C<%Config> describes compilers that aren't there, and extension building
288fails. This forces people into choosing between re-compiling perl themselves
289using the compiler they have, or only using modules that the vendor ships.
290
291It would be good to find a way teach C<Config.pm> about the installation setup,
292possibly involving probing at install time or later, so that the C<%Config> in
293a binary distribution better describes the installed machine, when the
294installed machine differs from the build machine in some significant way.
295
728f4ecd
NC
296=head2 linker specification files
297
298Some platforms mandate that you provide a list of a shared library's external
299symbols to the linker, so the core already has the infrastructure in place to
300do this for generating shared perl libraries. My understanding is that the
301GNU toolchain can accept an optional linker specification file, and restrict
302visibility just to symbols declared in that file. It would be good to extend
303F<makedef.pl> to support this format, and to provide a means within
304C<Configure> to enable it. This would allow Unix users to test that the
305export list is correct, and to build a perl that does not pollute the global
306namespace with private symbols.
307
8523e164 308
0bdfc961
NC
309
310
311=head1 Tasks that need a little C knowledge
312
313These tasks would need a little C knowledge, but don't need any specific
314background or experience with XS, or how the Perl interpreter works
315
316=head2 Make it clear from -v if this is the exact official release
89007cb3 317
617eabfa
NC
318Currently perl from C<p4>/C<rsync> ships with a F<patchlevel.h> file that
319usually defines one local patch, of the form "MAINT12345" or "RC1". The output
320of perl -v doesn't report that a perl isn't an official release, and this
89007cb3 321information can get lost in bugs reports. Because of this, the minor version
fa11829f 322isn't bumped up until RC time, to minimise the possibility of versions of perl
89007cb3
NC
323escaping that believe themselves to be newer than they actually are.
324
325It would be useful to find an elegant way to have the "this is an interim
326maintenance release" or "this is a release candidate" in the terse -v output,
327and have it so that it's easy for the pumpking to remove this just as the
328release tarball is rolled up. This way the version pulled out of rsync would
329always say "I'm a development release" and it would be safe to bump the
330reported minor version as soon as a release ships, which would aid perl
331developers.
332
0bdfc961
NC
333This task is really about thinking of an elegant way to arrange the C source
334such that it's trivial for the Pumpking to flag "this is an official release"
335when making a tarball, yet leave the default source saying "I'm not the
336official release".
337
0f788cd2
NC
338=head2 Ordering of "global" variables.
339
340F<thrdvar.h> and F<intrpvarh> define the "global" variables that need to be
341per-thread under ithreads, where the variables are actually elements in a
342structure. As C dictates, the variables must be laid out in order of
343declaration. There is a comment
344C</* Important ones in the first cache line (if alignment is done right) */>
345which implies that at some point in the past the ordering was carefully chosen
346(at least in part). However, it's clear that the ordering is less than perfect,
347as currently there are things such as 7 C<bool>s in a row, then something
348typically requiring 4 byte alignment, and then an odd C<bool> later on.
349(C<bool>s are typically defined as C<char>s). So it would be good for someone
350to review the ordering of the variables, to see how much alignment padding can
351be removed.
352
d7939546
NC
353It's also worth checking that all variables are actually used. Perl 5.8.0
354shipped with C<PL_nrs> still defined in F<thrdvar.h>, despite it being unused
355since a change over a year earlier. Had this been spotted before release, it
356could have been removed, but now it has to remain in the 5.8.x releases to
357keep the structure the same size, to retain binary compatibility.
358
c1ab7b38
NC
359It's probably worth checking if all need to be the types they are. For example
360
361 PERLVAR(Ierror_count, I32) /* how many errors so far, max 10 */
362
363might work as well if stored in a signed (or unsigned) 8 bit value, if the
364comment is accurate. C<PL_multi_open> and C<PL_multi_close> can probably
365become C<char>s. Finding variables to downsize coupled with rearrangement
366could shrink the interpreter structure; a size saving which is multiplied by
367the number of threads running.
368
fee0a0f7 369=head2 Profile Perl - am I hot or not?
62403a3c 370
fee0a0f7
NC
371The Perl source code is stable enough that it makes sense to profile it,
372identify and optimise the hotspots. It would be good to measure the
373performance of the Perl interpreter using free tools such as cachegrind,
374gprof, and dtrace, and work to reduce the bottlenecks they reveal.
375
376As part of this, the idea of F<pp_hot.c> is that it contains the I<hot> ops,
377the ops that are most commonly used. The idea is that by grouping them, their
378object code will be adjacent in the executable, so they have a greater chance
379of already being in the CPU cache (or swapped in) due to being near another op
380already in use.
62403a3c
NC
381
382Except that it's not clear if these really are the most commonly used ops. So
fee0a0f7
NC
383as part of exercising your skills with coverage and profiling tools you might
384want to determine what ops I<really> are the most commonly used. And in turn
385suggest evictions and promotions to achieve a better F<pp_hot.c>.
62403a3c 386
98fed0ad
NC
387=head2 Shrink struct context
388
389In F<cop.h>, we have
390
391 struct context {
392 U32 cx_type; /* what kind of context this is */
393 union {
394 struct block cx_blk;
395 struct subst cx_subst;
396 } cx_u;
397 };
398
399There are less than 256 values for C<cx_type>, and the constituent parts
400C<struct block> and C<struct subst> both contain some C<U8> and C<U16> fields,
401so it should be possible to move them to the first word, and share space with
402a C<U8> C<cx_type>, saving 1 word.
403
404=head2 Allocate OPs from arenas
405
406Currently all new OP structures are individually malloc()ed and free()d.
407All C<malloc> implementations have space overheads, and are now as fast as
408custom allocates so it would both use less memory and less CPU to allocate
409the various OP structures from arenas. The SV arena code can probably be
410re-used for this.
411
55585837 412=head2 Merge the win32 and wince codebases
0bdfc961 413
55585837
SP
414Currently, code used to build Perl on Win32 and WinCE are maintained
415separately, but use much of the same code. We currently have a very high
416probability of the code diverging when it shouldn't. Ideally, the code
417for the two systems should be merged so that common code between the two
418could be shared.
0bdfc961
NC
419
420
0bdfc961 421=head1 Tasks that need a knowledge of XS
e50bb9a1 422
0bdfc961
NC
423These tasks would need C knowledge, and roughly the level of knowledge of
424the perl API that comes from writing modules that use XS to interface to
425C.
426
f23930d5 427=head2 shrink C<PVBM>s
4a750395 428
35b64ab6 429By removing unused elements and careful re-ordering, the structures for C<AV>s,
f23930d5
NC
430C<HV>s, C<CV>s and C<GV>s have recently been shrunk considerably. C<PVIO>s
431probably aren't worth it, as typical programs don't use more than 8, and
432(at least) C<Filter::Util::Call> uses C<SvPVX>/C<SvCUR>/C<SvLEN> on a C<PVIO>,
433so it would mean code changes to modules on CPAN. C<PVBM>s might have some
434savings to win.
4a750395 435
0bdfc961
NC
436=head2 Implicit Latin 1 => Unicode translation
437
438Conversions from byte strings to UTF-8 currently map high bit characters
439to Unicode without translation (or, depending on how you look at it, by
440implicitly assuming that the byte strings are in Latin-1). As perl assumes
441the C locale by default, upgrading a string to UTF-8 may change the
442meaning of its contents regarding character classes, case mapping, etc.
443This should probably emit a warning (at least).
444
445This task is incremental - even a little bit of work on it will help.
e50bb9a1 446
cd793d32 447=head2 autovivification
e50bb9a1 448
cd793d32 449Make all autovivification consistent w.r.t LVALUE/RVALUE and strict/no strict;
e50bb9a1 450
0bdfc961 451This task is incremental - even a little bit of work on it will help.
e50bb9a1 452
0bdfc961 453=head2 Unicode in Filenames
e50bb9a1 454
0bdfc961
NC
455chdir, chmod, chown, chroot, exec, glob, link, lstat, mkdir, open,
456opendir, qx, readdir, readlink, rename, rmdir, stat, symlink, sysopen,
457system, truncate, unlink, utime, -X. All these could potentially accept
458Unicode filenames either as input or output (and in the case of system
459and qx Unicode in general, as input or output to/from the shell).
460Whether a filesystem - an operating system pair understands Unicode in
461filenames varies.
e50bb9a1 462
0bdfc961
NC
463Known combinations that have some level of understanding include
464Microsoft NTFS, Apple HFS+ (In Mac OS 9 and X) and Apple UFS (in Mac
465OS X), NFS v4 is rumored to be Unicode, and of course Plan 9. How to
466create Unicode filenames, what forms of Unicode are accepted and used
467(UCS-2, UTF-16, UTF-8), what (if any) is the normalization form used,
468and so on, varies. Finding the right level of interfacing to Perl
469requires some thought. Remember that an OS does not implicate a
470filesystem.
e50bb9a1 471
0bdfc961
NC
472(The Windows -C command flag "wide API support" has been at least
473temporarily retired in 5.8.1, and the -C has been repurposed, see
474L<perlrun>.)
969e704b 475
0bdfc961 476=head2 Unicode in %ENV
969e704b 477
0bdfc961 478Currently the %ENV entries are always byte strings.
e50bb9a1 479
0bdfc961 480=head2 use less 'memory'
e50bb9a1 481
0bdfc961
NC
482Investigate trade offs to switch out perl's choices on memory usage.
483Particularly perl should be able to give memory back.
e50bb9a1 484
0bdfc961 485This task is incremental - even a little bit of work on it will help.
0abe3f7c 486
0bdfc961 487=head2 Re-implement C<:unique> in a way that is actually thread-safe
0abe3f7c 488
0bdfc961
NC
489The old implementation made bad assumptions on several levels. A good 90%
490solution might be just to make C<:unique> work to share the string buffer
491of SvPVs. That way large constant strings can be shared between ithreads,
492such as the configuration information in F<Config>.
0abe3f7c 493
0bdfc961 494=head2 Make tainting consistent
0abe3f7c 495
0bdfc961
NC
496Tainting would be easier to use if it didn't take documented shortcuts and
497allow taint to "leak" everywhere within an expression.
0abe3f7c 498
0bdfc961 499=head2 readpipe(LIST)
0abe3f7c 500
0bdfc961
NC
501system() accepts a LIST syntax (and a PROGRAM LIST syntax) to avoid
502running a shell. readpipe() (the function behind qx//) could be similarly
503extended.
0abe3f7c 504
e50bb9a1 505
e50bb9a1 506
e50bb9a1 507
f86a8bc5 508
0bdfc961 509=head1 Tasks that need a knowledge of the interpreter
3298bd4d 510
0bdfc961
NC
511These tasks would need C knowledge, and knowledge of how the interpreter works,
512or a willingness to learn.
3298bd4d 513
0bdfc961
NC
514=head2 lexical pragmas
515
78ef48ad
RGS
516Document the new support for lexical pragmas in 5.9.3 and how %^H works.
517Maybe C<re>, C<encoding>, maybe other pragmas could be made lexical.
0562c0e3 518
d10fc472 519=head2 Attach/detach debugger from running program
1626a787 520
cd793d32
NC
521The old perltodo notes "With C<gdb>, you can attach the debugger to a running
522program if you pass the process ID. It would be good to do this with the Perl
0bdfc961
NC
523debugger on a running Perl program, although I'm not sure how it would be
524done." ssh and screen do this with named pipes in /tmp. Maybe we can too.
1626a787 525
0bdfc961
NC
526=head2 LVALUE functions for lists
527
528The old perltodo notes that lvalue functions don't work for list or hash
529slices. This would be good to fix.
530
531=head2 LVALUE functions in the debugger
532
533The old perltodo notes that lvalue functions don't work in the debugger. This
534would be good to fix.
535
536=head2 _ prototype character
537
538Study the possibility of adding a new prototype character, C<_>, meaning
539"this argument defaults to $_".
540
4e577f8b
NC
541=head2 state variables
542
543C<my $foo if 0;> is deprecated, and should be replaced with
544C<state $x = "initial value\n";> the syntax from Perl 6.
16fc99ce 545Rafael has sent a first cut patch to perl5-porters.
4e577f8b 546
0bdfc961
NC
547=head2 regexp optimiser optional
548
549The regexp optimiser is not optional. It should configurable to be, to allow
550its performance to be measured, and its bugs to be easily demonstrated.
551
552=head2 UNITCHECK
553
554Introduce a new special block, UNITCHECK, which is run at the end of a
555compilation unit (module, file, eval(STRING) block). This will correspond to
556the Perl 6 CHECK. Perl 5's CHECK cannot be changed or removed because the
557O.pm/B.pm backend framework depends on it.
558
559=head2 optional optimizer
560
561Make the peephole optimizer optional. Currently it performs two tasks as
562it walks the optree - genuine peephole optimisations, and necessary fixups of
563ops. It would be good to find an efficient way to switch out the
564optimisations whilst keeping the fixups.
565
566=head2 You WANT *how* many
567
568Currently contexts are void, scalar and list. split has a special mechanism in
569place to pass in the number of return values wanted. It would be useful to
570have a general mechanism for this, backwards compatible and little speed hit.
571This would allow proposals such as short circuiting sort to be implemented
572as a module on CPAN.
573
574=head2 lexical aliases
575
576Allow lexical aliases (maybe via the syntax C<my \$alias = \$foo>.
577
578=head2 entersub XS vs Perl
579
580At the moment pp_entersub is huge, and has code to deal with entering both
581perl and XS subroutines. Subroutine implementations rarely change between
582perl and XS at run time, so investigate using 2 ops to enter subs (one for
583XS, one for perl) and swap between if a sub is redefined.
2810d901
NC
584
585=head2 Self ties
586
587self ties are currently illegal because they caused too many segfaults. Maybe
588the causes of these could be tracked down and self-ties on all types re-
589instated.
0bdfc961
NC
590
591=head2 Optimize away @_
592
593The old perltodo notes "Look at the "reification" code in C<av.c>".
594
0bdfc961
NC
595=head2 What hooks would assertions need?
596
597Assertions are in the core, and work. However, assertions needed to be added
598as a core patch, rather than an XS module in ext, or a CPAN module, because
599the core has no hooks in the necessary places. It would be useful to
600investigate what hooks would need to be added to make it possible to provide
601the full assertion support from a CPAN module, so that we aren't constraining
602the imagination of future CPAN authors.
603
16fc99ce
NC
604=head2 Properly Unicode safe tokeniser and pads.
605
606The tokeniser isn't actually very UTF-8 clean. C<use utf8;> is a hack -
607variable names are stored in stashes as raw bytes, without the utf-8 flag
608set. The pad API only takes a C<char *> pointer, so that's all bytes too. The
609tokeniser ignores the UTF-8-ness of C<PL_rsfp>, or any SVs returned from
610source filters. All this could be fixed.
611
0bdfc961
NC
612
613
614
615
0bdfc961
NC
616=head1 Big projects
617
618Tasks that will get your name mentioned in the description of the "Highlights
619of 5.10"
620
621=head2 make ithreads more robust
622
4e577f8b 623Generally make ithreads more robust. See also L</iCOW>
0bdfc961
NC
624
625This task is incremental - even a little bit of work on it will help, and
626will be greatly appreciated.
627
6c047da7
YST
628One bit would be to write the missing code in sv.c:Perl_dirp_dup.
629
0bdfc961
NC
630=head2 iCOW
631
632Sarathy and Arthur have a proposal for an improved Copy On Write which
633specifically will be able to COW new ithreads. If this can be implemented
634it would be a good thing.
635
636=head2 (?{...}) closures in regexps
637
638Fix (or rewrite) the implementation of the C</(?{...})/> closures.
639
640=head2 A re-entrant regexp engine
641
642This will allow the use of a regex from inside (?{ }), (??{ }) and
643(?(?{ })|) constructs.