http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/
-=head1 To do during 5.6.x
+=head1 assertions
-=head2 Support for I/O disciplines
+Clean up and finish support for assertions. See L<assertions>.
-C<perlio> provides this, but the interface could be a lot more
-straightforward.
+=head1 iCOW
-=head2 Autoload bytes.pm
+Sarathy and Arthur have a proposal for an improved Copy On Write which
+specifically will be able to COW new ithreads. If this can be implemented
+it would be a good thing.
-When the lexer sees, for instance, C<bytes::length>, it should
-automatically load the C<bytes> pragma.
+=head1 (?{...}) closures in regexps
-=head2 Make "\u{XXXX}" et al work
+Fix (or rewrite) the implementation of the C</(?{...})/> closures.
-Danger, Will Robinson! Discussing the semantics of C<"\x{F00}">,
-C<"\xF00"> and C<"\U{F00}"> on P5P I<will> lead to a long and boring
-flamewar.
+=head1 A re-entrant regexp engine
-=head2 Create a char *sv_pvprintify(sv, STRLEN *lenp, UV flags)
+This will allow the use of a regex from inside (?{ }), (??{ }) and
+(?(?{ })|) constructs.
-For displaying PVs with control characters, embedded nulls, and Unicode.
-This would be useful for printing warnings, or data and regex dumping,
-not_a_number(), and so on.
+=head1 pragmata
-Requirements: should handle both byte and UTF8 strings. isPRINT()
-characters printed as-is, character less than 256 as \xHH, Unicode
-characters as \x{HHH}. Don't assume ASCII-like, either, get somebody
-on EBCDIC to test the output.
+=head2 lexical pragmas
-Possible options, controlled by the flags:
-- whitespace (other than ' ' of isPRINT()) printed as-is
-- use isPRINT_LC() instead of isPRINT()
-- print control characters like this: "\cA"
-- print control characters like this: "^A"
-- non-PRINTables printed as '.' instead of \xHH
-- use \OOO instead of \xHH
-- use the C/Perl-metacharacters like \n, \t
-- have a maximum length for the produced string (read it from *lenp)
-- append a "..." to the produced string if the maximum length is exceeded
-- really fancy: print unicode characters as \N{...}
+Reimplement the mechanism of lexical pragmas to be more extensible. Fix
+current pragmas that don't work well (or at all) with lexical scopes or in
+run-time eval(STRING) (C<sort>, C<re>, C<encoding> for example). MJD has a
+preliminary patch that implements this.
-NOTE: pv_display(), pv_uni_display(), sv_uni_display() are already
-doing something like the above.
+=head2 use less 'memory'
-=head2 Overloadable regex assertions
+Investigate trade offs to switch out perl's choices on memory usage.
+Particularly perl should be able to give memory back.
-This may or may not be possible with the current regular expression
-engine. The idea is that, for instance, C<\b> needs to be
-algorithmically computed if you're dealing with Thai text. Hence, the
-B<\b> assertion wants to be overloaded by a function.
+=head1 prototypes and functions
-=head2 Unicode
+=head2 _ prototype character
-=over 4
+Study the possibility of adding a new prototype character, C<_>, meaning
+"this argument defaults to $_".
-=item *
+=head2 inlining autoloaded constants
-Allow for long form of the General Category Properties, e.g
-C<\p{IsOpenPunctuation}>, not just the abbreviated form, e.g.
-C<\p{IsPs}>.
-
-=item *
-
-Allow for the metaproperties: C<XID Start>, C<XID Continue>,
-C<NF*_NO>, C<NF*_MAYBE> (require the DerivedCoreProperties and
-DerviceNormalizationProperties files).
-
-There are also multiple value properties still unimplemented:
-C<Numeric Type>, C<East Asian Width>.
-
-=item *
-
- Case Mappings? http://www.unicode.org/unicode/reports/tr21/
-
-Mostly implemented (all of 1:1, 1:N, N:1), only the "final sigma"
-and locale-specific rules of SpecCase are not implemented.
-
-=item *
-
-UTF-8 identifier names should probably be canonicalized: NFC?
-
-=item *
-
-UTF-8 in package names and sub names? The first is problematic
-because of the mapping to pathnames, ditto for the second one if
-one does autosplitting, for example. Some of this works already
-in 5.8.0, but essentially it is unsupported. Constructs to consider,
-at the very least:
-
- use utf8;
- package UnicodePackage;
- sub new { bless {}, shift };
- sub UnicodeMethod1 { ... $_[0]->UnicodeMethod2(...) ... }
- sub UnicodeMethod2 { ... } # in here caller(0) should contain Unicode
- ...
- package main;
- my $x = UnicodePackage->new;
- print ref $x, "\n"; # should be Unicode
- $x->UnicodeMethod1(...);
- my $y = UnicodeMethod3 UnicodePackage ...;
-
-In the above all I<UnicodeXxx> contain (identifier-worthy) characters
-beyond the code point 255, for example 256. Wherever package/class or
-subroutine names can be returned needs to be checked for Unicodeness.
-
-=back
-
-See L<perlunicode/UNICODE REGULAR EXPRESSION SUPPORT LEVEL> for what's
-there and what's missing. Almost all of Levels 2 and 3 is missing,
-and as of 5.8.0 not even all of Level 1 is there.
-They have some tricks Perl doesn't yet implement, such as character
-class subtraction.
-
- http://www.unicode.org/unicode/reports/tr18/
-
-=head2 Work out exit/die semantics for threads
-
-There are some suggestions to use for example something like this:
-default to "(thread exiting first will) wait for the other threads
-until up to 60 seconds". Other possibilities:
-
- use threads wait => 0;
-
-Do not wait.
-
- use threads wait_for => 10;
-
-Wait up to 10 seconds.
-
- use threads wait_for => -1;
-
-Wait for ever.
-
-http://archive.develooper.com/perl5-porters@perl.org/msg79618.html
-
-=head2 Better support for nonpreemptive threading systems like GNU pth
-
-To better support nonpreemptive threading systems, perhaps some of the
-blocking functions internally in Perl should do a yield() before a
-blocking call. (Now certain threads tests ({basic,list,thread.t})
-simply do a yield() before they sleep() to give nonpreemptive thread
-implementations a chance).
-
-In some cases, like the GNU pth, which has replacement functions that
-are nonblocking (pth_select instead of select), maybe Perl should be
-using them instead when built for threading.
-
-=head2 Typed lexicals for compiler
-
-=head2 Compiler workarounds for Win32
-
-=head2 AUTOLOADing in the compiler
-
-=head2 Fixing comppadlist when compiling
-
-=head2 Cleaning up exported namespace
-
-=head2 Complete signal handling
-
-Add C<PERL_ASYNC_CHECK> to opcodes which loop; replace C<sigsetjmp> with
-C<sigjmp>; check C<wait> for signal safety.
-
-=head2 Out-of-source builds
-
-This was done for 5.6.0, but needs reworking for 5.7.x
-
-=head2 POSIX realtime support
-
-POSIX 1003.1 1996 Edition support--realtime stuff: POSIX semaphores,
-message queues, shared memory, realtime clocks, timers, signals (the
-metaconfig units mostly already exist for these)
-
-=head2 UNIX98 support
-
-Reader-writer locks, realtime/asynchronous IO
-
-=head2 IPv6 Support
-
-There are non-core modules, such as C<Socket6>, but these will need
-integrating when IPv6 actually starts to really happen. See RFC 2292
-and RFC 2553.
-
-=head2 Long double conversion
-
-Floating point formatting is still causing some weird test failures.
-
-=head2 Locales
-
-Locales and Unicode interact with each other in unpleasant ways.
-One possible solution would be to adopt/support ICU:
-
- http://oss.software.ibm.com/developerworks/opensource/icu/project/
-
-=head2 Arithmetic on non-Arabic numerals
-
-C<[1234567890]> aren't the only numerals any more.
-
-=head2 POSIX Unicode character classes
-
-(C<[=a=]> for equivalence classes, C<[.ch.]> for collation.)
-These are dependent on Unicode normalization and collation.
-
-=head2 Factoring out common suffices/prefices in regexps (trie optimization)
-
-Currently, the user has to optimize C<foo|far> and C<foo|goo> into
-C<f(?:oo|ar)> and C<[fg]oo> by hand; this could be done automatically.
-
-=head2 Security audit shipped utilities
-
-All the code we ship with Perl needs to be sensible about temporary file
-handling, locking, input validation, and so on.
-
-=head2 Sort out the uid-setting mess
-
-Currently there are several problems with the setting of uids ($<, $>
-for the real and effective uids). Firstly, what exactly setuid() call
-gets invoked in which platform is simply a big mess that needs to be
-untangled. Secondly, the effects are apparently not standard across
-platforms, (if you first set $< and then $>, or vice versa, being
-uid == euid == zero, or just euid == zero, or as a normal user, what are
-the results?). The test suite not (usually) being run as root means
-that these things do not get much testing. Thirdly, there's quite
-often a third uid called saved uid, and Perl has no knowledge of that
-feature in any way. (If one has the saved uid of zero, one can get
-back any real and effective uids.) As an example, to change also the
-saved uid, one needs to set the real and effective uids B<twice>-- in
-most systems, that is: in HP-UX that doesn't seem to work.
-
-=head2 Custom opcodes
-
-Have a way to introduce user-defined opcodes without the subroutine call
-overhead of an XSUB; the user should be able to create PP code. Simon
-Cozens has some ideas on this.
-
-=head2 DLL Versioning
-
-Windows needs a way to know what version of an XS or C<libperl> DLL it's
-loading.
-
-=head2 Introduce @( and @)
-
-C<$(> may return "foo bar baz". Unfortunately, since groups can
-theoretically have spaces in their names, this could be one, two or
-three groups.
-
-=head2 Floating point handling
-
-C<NaN> and C<inf> support is particularly troublesome.
-(fp_classify(), fp_class(), fp_class_d(), class(), isinf(),
-isfinite(), finite(), isnormal(), unordered(), <ieeefp.h>,
-<fp_class.h> (there are metaconfig units for all these) (I think),
-fp_setmask(), fp_getmask(), fp_setround(), fp_getround()
-(no metaconfig units yet for these). Don't forget finitel(), fp_classl(),
-fp_class_l(), (yes, both do, unfortunately, exist), and unorderedl().)
-
-As of Perl 5.6.1, there is a Perl macro, Perl_isnan().
-
-=head2 IV/UV preservation
-
-Nicholas Clark has done a lot of work on this, but work is continuing.
-C<+>, C<-> and C<*> work, but guards need to be in place for C<%>, C</>,
-C<&>, C<oct>, C<hex> and C<pack>.
-
-=head2 Replace pod2html with something using Pod::Parser
-
-The CPAN module C<Marek::Pod::Html> may be a more suitable basis for a
-C<pod2html> converter; the current one duplicates the functionality
-abstracted in C<Pod::Parser>, which makes updating the POD language
-difficult.
-
-=head2 Automate module testing on CPAN
-
-When a new Perl is being beta tested, porters have to manually grab
-their favourite CPAN modules and test them - this should be done
-automatically.
-
-=head2 sendmsg and recvmsg
-
-We have all the other BSD socket functions but these. There are
-metaconfig units for these functions which can be added. To avoid these
-being new opcodes, a solution similar to the way C<sockatmark> was added
-would be preferable. (Autoload the C<IO::whatever> module.)
-
-=head2 Rewrite perlre documentation
-
-The new-style patterns need full documentation, and the whole document
-needs to be a lot clearer.
-
-=head2 Convert example code to IO::Handle filehandles
-
-=head2 Document Win32 choices
-
-=head2 Check new modules
-
-=head2 Make roffitall find pods and libs itself
-
-Simon Cozens has done some work on this but it needs a rethink.
-
-=head1 To do at some point
-
-These are ideas that have been regularly tossed around, that most
-people believe should be done maybe during 5.8.x
-
-=head2 Remove regular expression recursion
-
-Because the regular expression engine is recursive, badly designed
-expressions can lead to lots of recursion filling up the stack. Ilya
-claims that it is easy to convert the engine to being iterative, but
-this has still not yet been done. There may be a regular expression
-engine hit squad meeting at TPC5.
-
-=head2 Memory leaks after failed eval
-
-Perl will leak memory if you C<eval "hlagh hlagh hlagh hlagh">. This is
-partially because it attempts to build up an op tree for that code and
-doesn't properly free it. The same goes for non-syntactically-correct
-regular expressions. Hugo looked into this, but decided it needed a
-mark-and-sweep GC implementation.
-
-Alan notes that: The basic idea was to extend the parser token stack
-(C<YYSTYPE>) to include a type field so we knew what sort of thing each
-element of the stack was. The F<perly.c> code would then have to be
-postprocessed to record the type of each entry on the stack as it was
-created, and the parser patched so that it could unroll the stack
-properly on error.
-
-This is possible to do, but would be pretty messy to implement, as it
-would rely on even more sed hackery in F<perly.fixer>.
-
-=head2 bitfields in pack
-
-=head2 Cross compilation
-
-Make Perl buildable with a cross-compiler. This will play havoc with
-Configure, which needs to know how the target system will respond to
-its tests; maybe C<microperl> will be a good starting point here.
-(Indeed, Bart Schuller reports that he compiled up C<microperl> for
-the Agenda PDA and it works fine.) A really big spanner in the works
-is the bootstrapping build process of Perl: if the filesystem the
-target systems sees is not the same what the build host sees, various
-input, output, and (Perl) library files need to be copied back and forth.
-
-As of 5.8.0 Configure mostly works for cross-compilation
-(used successfully for iPAQ Linux), miniperl gets built,
-but then building DynaLoader (and other extensions) fails
-since MakeMaker knows nothing of cross-compilation.
-(See INSTALL/Cross-compilation for the state of things.)
-
-=head2 Perl preprocessor / macros
-
-Source filters help with this, but do not get us all the way. For
-instance, it should be possible to implement the C<??> operator somehow;
-source filters don't (quite) cut it.
-
-=head2 Perl lexer in Perl
-
-Damian Conway is planning to work on this, but it hasn't happened yet.
-
-=head2 Using POSIX calls internally
-
-When faced with a BSD vs. SysV -style interface to some library or
-system function, perl's roots show in that it typically prefers the BSD
-interface (but falls back to the SysV one). One example is getpgrp().
-Other examples include C<memcpy> vs. C<bcopy>. There are others, mostly in
-F<pp_sys.c>.
-
-Mostly, this item is a suggestion for which way to start a journey into
-an C<#ifdef> forest. It is not primarily a suggestion to eliminate any of
-the C<#ifdef> forests.
-
-POSIX calls are perhaps more likely to be portable to unexpected
-architectures. They are also perhaps more likely to be actively
-maintained by a current vendor. They are also perhaps more likely to be
-available in thread-safe versions, if appropriate.
-
-=head2 -i rename file when changed
-
-It's only necessary to rename a file when inplace editing when the file
-has changed. Detecting a change is perhaps the difficult bit.
-
-=head2 All ARGV input should act like E<lt>E<gt>
-
-eg C<read(ARGV, ...)> doesn't currently read across multiple files.
-
-=head2 Support for rerunning debugger
-
-There should be a way of restarting the debugger on demand.
-
-=head2 Test Suite for the Debugger
-
-The debugger is a complex piece of software and fixing something
-here may inadvertently break something else over there. To tame
-this chaotic behaviour, a test suite is necessary.
-
-=head2 my sub foo { }
-
-The basic principle is sound, but there are problems with the semantics
-of self-referential and mutually referential lexical subs: how to
-declare the subs?
-
-=head2 One-pass global destruction
-
-Sweeping away all the allocated memory in one go is a laudable goal, but
-it's difficult and in most cases, it's easier to let the memory get
-freed by exiting.
-
-=head2 Rewrite regexp parser
-
-There has been talk recently of rewriting the regular expression parser
-to produce an optree instead of a chain of opcodes; it's unclear whether
-or not this would be a win.
-
-=head2 Cache recently used regexps
-
-This is to speed up
-
- for my $re (@regexps) {
- $matched++ if /$re/
- }
-
-C<qr//> already gives us a way of saving compiled regexps, but it should
-be done automatically.
-
-=head2 Cross-compilation support
-
-Bart Schuller reports that using C<microperl> and a cross-compiler, he
-got Perl working on the Agenda PDA. However, one cannot build a full
-Perl because Configure needs to get the results for the target platform,
-for the host.
-
-=head2 Bit-shifting bitvectors
-
-Given:
-
- vec($v, 1000, 1) = 1;
-
-One should be able to do
-
- $v <<= 1;
-
-and have the 999'th bit set.
-
-Currently if you try with shift bitvectors you shift the NV/UV, instead
-of the bits in the PV. Not very logical.
-
-=head2 debugger pragma
-
-The debugger is implemented in Perl in F<perl5db.pl>; turning it into a
-pragma should be easy, but making it work lexically might be more
-difficult. Fiddling with C<$^P> would be necessary.
-
-=head2 use less pragma
-
-Identify areas where speed/memory tradeoffs can be made and have a hint
-to switch between them.
-
-=head2 switch structures
-
-Although we have C<Switch.pm> in core, Larry points to the dormant
-C<nswitch> and C<cswitch> ops in F<pp.c>; using these opcodes would be
-much faster.
-
-=head2 Cache eval tree
-
-=head2 rcatmaybe
-
-=head2 Shrink opcode tables
-
-=head2 Optimize away @_
-
-Look at the "reification" code in C<av.c>
-
-=head2 Prototypes versus indirect objects
-
-Currently, indirect object syntax bypasses prototype checks.
-
-=head2 Install HTML
-
-HTML versions of the documentation need to be installed by default; a
-call to C<installhtml> from C<installperl> may be all that's necessary.
-
-=head2 Prototype method calls
-
-=head2 Return context prototype declarations
-
-=head2 magic_setisa
-
-=head2 Garbage collection
-
-There have been persistent mumblings about putting a mark-and-sweep
-garbage detector into Perl; Alan Burlison has some ideas about this.
-
-=head2 IO tutorial
-
-Mark-Jason Dominus has the beginnings of one of these.
-
-=head2 Rewrite perldoc
-
-There are a few suggestions for what to do with C<perldoc>: maybe a
-full-text search, an index function, locating pages on a particular
-high-level subject, and so on.
-
-=head2 Install .3p manpages
-
-This is a bone of contention; we can create C<.3p> manpages for each
-built-in function, but should we install them by default? Tcl does this,
-and it clutters up C<apropos>.
-
-=head2 Unicode tutorial
-
-Simon Cozens promises to do this before he gets old.
-
-=head2 Update POSIX.pm for 1003.1-2
-
-=head2 Retargetable installation
-
-Allow C<@INC> to be changed after Perl is built.
-
-=head2 POSIX emulation on non-POSIX systems
-
-Make C<POSIX.pm> behave as POSIXly as possible everywhere, meaning we
-have to implement POSIX equivalents for some functions if necessary.
-
-=head2 Rename Win32 headers
+Currently the optimiser can inline constants when expressed as subroutines
+with prototype ($) that return a constant. Likewise, many packages wrapping
+C libraries export lots of constants as subroutines which are AUTOLOADed on
+demand. However, these have no prototypes, so can't be seen as constants by
+the optimiser. Some way of cheaply (low syntax, low memory overhead) to the
+perl compiler that a name is a constant would be great, so that it knows to
+call the AUTOLOAD routine at compile time, and then inline the constant.
=head2 Finish off lvalue functions
-They don't work in the debugger, and they don't work for list or hash
-slices.
-
-=head2 Update sprintf documentation
-
-Hugo van der Sanden plans to look at this.
-
-=head2 Use fchown/fchmod internally
-
-This has been done in places, but needs a thorough code review.
-Also fchdir is available in some platforms.
-
-=head2 Make v-strings overloaded objects
-
-Instead of having to guess whether a string is a v-string and thus
-needs to be displayed with %vd, make v-strings (readonly) objects
-(class "vstring"?) with a stringify overload.
-
-=head2 Allow restricted hash assignment
-
-Currently you're not allowed to assign to a restricted hash at all,
-even with the same keys.
-
- %restricted = (foo => 42); # error
-
-This should be allowed if the new keyset is a subset of the old
-keyset. May require more extra code than we'd like in pp_aassign.
-
-=head2 Should overload be inheritable?
-
-Should overload be 'contagious' through @ISA so that derived classes
-would inherit their base classes' overload definitions? What to do
-in case of overload conflicts?
+The old perltodo notes "They don't work in the debugger, and they don't work for
+list or hash slices."
-=head2 Taint rethink
+=head1 Unicode and UTF8
-Should taint be stopped from affecting control flow, if ($tainted)?
-Should tainted symbolic method calls and subref calls be stopped?
-(Look at Ruby's $SAFE levels for inspiration?)
-
-=head1 Vague ideas
-
-Ideas which have been discussed, and which may or may not happen.
-
-=head2 ref() in list context
-
-It's unclear what this should do or how to do it without breaking old
-code.
-
-=head2 Make tr/// return histogram of characters in list context
-
-There is a patch for this, but it may require Unicodification.
-
-=head2 Compile to real threaded code
-
-=head2 Structured types
-
-=head2 Modifiable $1 et al.
-
- ($x = "elephant") =~ /e(ph)/;
- $1 = "g"; # $x = "elegant"
-
-What happens if there are multiple (nested?) brackets? What if the
-string changes between the match and the assignment?
-
-=head2 Procedural interfaces for IO::*, etc.
-
-Some core modules have been accused of being overly-OO. Adding
-procedural interfaces could demystify them.
-
-=head2 RPC modules
-
-=head2 Attach/detach debugger from running program
+=head2 Implicit Latin 1 => Unicode translation
-With C<gdb>, you can attach the debugger to a running program if you
-pass the process ID. It would be good to do this with the Perl debugger
-on a running Perl program, although I'm not sure how it would be done.
+Conversions from byte strings to UTF-8 currently map high bit characters
+to Unicode without translation (or, depending on how you look at it, by
+implicitly assuming that the byte strings are in Latin-1). As perl assumes
+the C locale by default, upgrading a string to UTF-8 may change the
+meaning of its contents regarding character classes, case mapping, etc.
+This should probably emit a warning (at least).
-=head2 GUI::Native
+=head2 UTF8 caching code
-A non-core module that would use "native" GUI to create graphical
-applications.
-
-=head2 foreach(reverse ...)
-
-Currently
-
- foreach (reverse @_) { ... }
-
-puts C<@_> on the stack, reverses it putting the reversed version on the
-stack, then iterates forwards. Instead, it could be special-cased to put
-C<@_> on the stack then iterate backwards.
-
-=head2 Constant function cache
-
-=head2 Approximate regular expression matching
-
-=head1 Ongoing
-
-These items B<always> need doing:
-
-=head2 Update guts documentation
-
-Simon Cozens tries to do this when possible, and contributions to the
-C<perlapi> documentation is welcome.
-
-=head2 Add more tests
-
-Michael Schwern will donate $500 to Yet Another Society when all core
-modules have tests.
-
-=head2 Update auxiliary tools
-
-The code we ship with Perl should look like good Perl 5.
-
-=head2 Create debugging macros
-
-Debugging macros (like printsv, dump) can make debugging perl inside a
-C debugger much easier. A good set for gdb comes with mod_perl.
-Something similar should be distributed with perl.
-
-The proper way to do this is to use and extend Devel::DebugInit.
-Devel::DebugInit also needs to be extended to support threads.
-
-See p5p archives for late May/early June 2001 for a recent discussion
-on this topic.
-
-=head2 truncate to the people
-
-One can emulate ftruncate() using F_FREESP and F_CHSIZ fcntls
-(see the UNIX FAQ for details). This needs to go somewhere near
-pp_sys.c:pp_truncate().
-
-One can emulate truncate() easily if one has ftruncate().
-This emulation should also go near pp_sys.pp_truncate().
+The string position/offset cache is not optional. It should be.
=head2 Unicode in Filenames
chdir, chmod, chown, chroot, exec, glob, link, lstat, mkdir, open,
opendir, qx, readdir, readlink, rename, rmdir, stat, symlink, sysopen,
-system, truncate, unlink, utime. All these could potentially accept
+system, truncate, unlink, utime, -X. All these could potentially accept
Unicode filenames either as input or output (and in the case of system
and qx Unicode in general, as input or output to/from the shell).
Whether a filesystem - an operating system pair understands Unicode in
requires some thought. Remember that an OS does not implicate a
filesystem.
-Note that in Windows the -C command line flag already does quite
-a bit of the above (but even there the support is not complete:
-for example the exec/spawn are not Unicode-aware) by turning on
-the so-called "wide API support".
-
-=head1 Recently done things
-
-These are things which have been on the todo lists in previous releases
-but have recently been completed.
-
-=head2 Alternative RE syntax module
-
-The C<Regexp::English> module, available from the CPAN, provides this:
-
- my $re = Regexp::English
- -> start_of_line
- -> literal('Flippers')
- -> literal(':')
- -> optional
- -> whitespace_char
- -> end
- -> remember
- -> multiple
- -> digit;
-
- /$re/;
-
-=head2 Safe signal handling
-
-A new signal model went into 5.7.1 without much fanfare. Operations and
-C<malloc>s are no longer interrupted by signals, which are handled
-between opcodes. This means that C<PERL_ASYNC_CHECK> now actually does
-something. However, there are still a few things that need to be done.
-
-=head2 Tie Modules
-
-Modules which implement arrays in terms of strings, substrings or files
-can be found on the CPAN.
-
-=head2 gettimeofday
+(The Windows -C command flag "wide API support" has been at least
+temporarily retired in 5.8.1, and the -C has been repurposed, see
+L<perlrun>.)
-C<Time::HiRes> has been integrated into the core.
+=head2 Unicode in %ENV
-=head2 setitimer and getimiter
+Currently the %ENV entries are always byte strings.
-Adding C<Time::HiRes> got us this too.
+=head1 Regexps
-=head2 Testing __DIE__ hook
+=head2 regexp optimiser optional
-Tests have been added.
+The regexp optimiser is not optional. It should configurable to be, to allow
+its performance to be measured, and its bugs to be easily demonstrated.
-=head2 CPP equivalent in Perl
+=head1 POD
-A C Yardley will probably have done this by the time you can read this.
-This allows for a generalization of the C constant detection used in
-building C<Errno.pm>.
+=head2 POD -> HTML conversion still sucks
-=head2 Explicit switch statements
+Which is crazy given just how simple POD purports to be, and how simple HTML
+can be.
-C<Switch.pm> has been integrated into the core to give you all manner of
-C<switch...case> semantics.
+=head1 Misc medium sized projects
-=head2 autocroak
+=head2 UNITCHECK
-This is C<Fatal.pm>.
+Introduce a new special block, UNITCHECK, which is run at the end of a
+compilation unit (module, file, eval(STRING) block). This will correspond to
+the Perl 6 CHECK. Perl 5's CHECK cannot be changed or removed because the
+O.pm/B.pm backend framework depends on it.
-=head2 UTF/EBCDIC
+=head2 optional optimizer
-Nick Ing-Simmons has made UTF-EBCDIC (UTR13) work with Perl.
+Make the peephole optimizer optional.
- EBCDIC? http://www.unicode.org/unicode/reports/tr16/
+=head2 You WANT *how* many
-=head2 UTF Regexes
+Currently contexts are void, scalar and list. split has a special mechanism in
+place to pass in the number of return values wanted. It would be useful to
+have a general mechanism for this, backwards compatible and little speed hit.
+This would allow proposals such as short circuiting sort to be implemented
+as a module on CPAN.
-Although there are probably some small bugs to be rooted out, Jarkko
-Hietaniemi has made regular expressions polymorphic between bytes and
-characters.
+=head2 lexical aliases
-=head2 perlcc to produce executable
+Allow lexical aliases (maybe via the syntax C<my \$alias = \$foo>.
-C<perlcc> was recently rewritten, and can now produce standalone
-executables.
+=head2 no 6
-=head2 END blocks saved in compiled output
+Make C<no 6> and C<no v6> work (opposite of C<use 5.005>, etc.).
-=head2 Secure temporary file module
+=head2 IPv6
-Tim Jenness' C<File::Temp> is now in core.
+Clean this up. Check everything in core works
-=head2 Integrate Time::HiRes
+=head2 entersub XS vs Perl
-This module is now part of core.
+At the moment pp_entersub is huge, and has code to deal with entering both
+perl and and XS subroutines. Subroutine implementations rarely change between
+perl and XS at run time, so investigate using 2 ops to enter subs (one for
+XS, one for perl) and swap between if a sub is redefined.
-=head2 Turn Cwd into XS
+=head2 @INC source filter to Filter::Simple
-Benjamin Sugars has done this.
+The second return value from a sub in @INC can be a source filter. This isn't
+documented. It should be changed to use Filter::Simple, tested and documented.
-=head2 Mmap for input
+=head2 bincompat functions
-Nick Ing-Simmons' C<perlio> supports an C<mmap> IO method.
+There are lots of functions which are retained for binary compatibility.
+Clean these up. Move them to mathom.c, and don't compile for blead?
-=head2 Byte to/from UTF8 and UTF8 to/from local conversion
-
-C<Encode> provides this.
-
-=head2 Add sockatmark support
-
-Added in 5.7.1
-
-=head2 Mailing list archives
-
-http://lists.perl.org/ , http://archive.develooper.com/
-
-=head2 Bug tracking
-
-Since 5.8.0 perl uses the RT bug tracking system from Jesse Vincent,
-implemented by Robert Spier at http://bugs.perl.org/
-
-=head2 Integrate MacPerl
-
-Chris Nandor and Matthias Neeracher have integrated the MacPerl changes
-into 5.6.0.
-
-=head2 Web "nerve center" for Perl
-
-http://use.perl.org/ is what you're looking for.
-
-=head2 Regular expression tutorial
-
-C<perlretut>, provided by Mark Kvale.
-
-=head2 Debugging Tutorial
-
-C<perldebtut>, written by Richard Foley.
-
-=head2 Integrate new modules
-
-Jarkko has been integrating madly into 5.7.x
-
-=head2 Integrate profiler
-
-C<Devel::DProf> is now a core module.
-
-=head2 Y2K error detection
-
-There's a configure option to detect unsafe concatenation with "19", and
-a CPAN module. (C<D'oh::Year>)
-
-=head2 Regular expression debugger
-
-While not part of core, Mark-Jason Dominus has written C<Rx> and has
-also come up with a generalised strategy for regular expression
-debugging.
-
-=head2 POD checker
-
-That's, uh, F<podchecker>
-
-=head2 "Dynamic" lexicals
-
-=head2 Cache precompiled modules
-
-=head1 Deprecated Wishes
+=head2 Use fchown/fchmod internally
-These are items which used to be in the todo file, but have been
-deprecated for some reason.
+The old perltodo notes "This has been done in places, but needs a thorough
+code review. Also fchdir is available in some platforms."
-=head2 Loop control on do{}
+=head2 Constant folding
-This would break old code; use C<do{{ }}> instead.
+The peephole optimiser should trap errors during constant folding, and give
+up on the folding, rather than bailing out at compile time. It is quite
+possible that the unfoldable constant is in unreachable code, eg something
+akin to C<$a = 0/0 if 0;>
-=head2 Lexically scoped typeglobs
+=head1 Tests
-Not needed now we have lexical IO handles.
+=head2 Make Schwern poorer
-=head2 format BOTTOM
+Tests for everything, At which point Schwern coughs up $500 to TPF.
-=head2 report HANDLE
+=head2 test B
-Damian Conway's text formatting modules seem to be the Way To Go.
+A test suite for the B module would be nice.
-=head2 Generalised want()/caller())
+=head2 common test code for timed bailout
-Robin Houston's C<Want> module does this.
+Write portable self destruct code for tests to stop them burning CPU in
+infinite loops. Needs to avoid using alarm, as some of the tests are testing
+alarm/sleep or timers.
-=head2 Named prototypes
+=head1 Installation
-This seems to be delayed until Perl 6.
+=head2 compressed man pages
-=head2 Built-in globbing
+Be able to install them
-The C<File::Glob> module has been used to replace the C<glob> function.
+=head2 Make Config.pm cope with differences between build and installed perl
-=head2 Regression tests for suidperl
+=head2 Relocatable perl
-C<suidperl> is deprecated in favour of common sense.
+Make it possible to create a relocatable perl binary. Will need some collusion
+with Config.pm. We could use a syntax of ... for location of current binary?
-=head2 Cached hash values
+=head2 make HTML install work
-We have shared hash keys, which perform the same job.
+=head2 put patchlevel in -v
-=head2 Add compression modules
+Currently perl from p4/rsync ships with a patchlevel.h file that usually
+defines one local patch, of the form "MAINT12345" or "RC1". The output of
+perl -v doesn't report that a perl isn't an official release, and this
+information can get lost in bugs reports. Because of this, the minor version
+isn't bumped up until RC time, to minimise the possibility of versions of perl
+escaping that believe themselves to be newer than they actually are.
-The compression modules are a little heavy; meanwhile, Nick Clark is
-working on experimental pragmata to do transparent decompression on
-input.
+It would be useful to find an elegant way to have the "this is an interim
+maintenance release" or "this is a release candidate" in the terse -v output,
+and have it so that it's easy for the pumpking to remove this just as the
+release tarball is rolled up. This way the version pulled out of rsync would
+always say "I'm a development release" and it would be safe to bump the
+reported minor version as soon as a release ships, which would aid perl
+developers.
-=head2 Reorganise documentation into tutorials/references
+=head1 Incremental things
-Could not get consensus on P5P about this.
+Some tasks that don't need to get done in one big hit.
-=head2 Remove distinction between functions and operators
+=head2 autovivification
-Caution: highly flammable.
+Make all autovivification consistent w.r.t LVALUE/RVALUE and strict/no strict;
-=head2 Make XS easier to use
+=head2 fix tainting bugs
-Use C<Inline> instead, or SWIG.
+Fix the bugs revealed by running the test suite with the C<-t> switch (via
+C<make test.taintwarn>).
-=head2 Make embedding easier to use
+=head2 Make tainting consistent
-Use C<Inline::CPR>.
+Tainting would be easier to use if it didn't take documented shortcuts and allow
+taint to "leak" everywhere within an expression.
-=head2 man for perl
+=head2 Dual life everything
-See the Perl Power Tools. ( http://language.perl.com/ppt/ )
+As part of the "dists" plan, anything that doesn't belong in the smallest perl
+distribution needs to be dual lifed. Anything else can be too.
-=head2 my $Package::variable
+=head1 Vague things
-Use C<our> instead.
+Some more nebulous ideas
-=head2 "or" tests defined, not truth
+=head2 threads
-Suggesting this on P5P B<will> cause a boring and interminable flamewar.
+Make threads more robust.
-=head2 "class"-based lexicals
+=head2 POSIX memory footprint
-Use flyweight objects, secure hashes or, dare I say it, pseudo-hashes instead.
-(Or whatever will replace pseudohashes in 5.10.)
+Ilya observed that use POSIX; eats memory like there's no tomorrow, and at
+various times worked to cut it down. There is probably still fat to cut out -
+for example POSIX passes Exporter some very memory hungry data structures.
-=head2 byteperl
+=head2 Optimize away @_
-C<ByteLoader> covers this.
+The old perltodo notes "Look at the "reification" code in C<av.c>".
-=head2 Lazy evaluation / tail recursion removal
+=head2 switch ops
-C<List::Util> gives first() (a short-circuiting grep); tail recursion
-removal is done manually, with C<goto &whoami;>. (However, MJD has
-found that C<goto &whoami> introduces a performance penalty, so maybe
-there should be a way to do this after all: C<sub foo {START: ... goto
-START;> is better.)
+The old perltodo notes "Although we have C<Switch.pm> in core, Larry points to
+the dormant C<nswitch> and C<cswitch> ops in F<pp.c>; using these opcodes would
+be much faster."
-=head2 Make "use utf8" the default
+=head2 Attach/detach debugger from running program
-Because of backward compatibility this is difficult: scripts could not
-contain B<any legacy eight-bit data> (like Latin-1) anymore, even in
-string literals or pod. Also would introduce a measurable slowdown of
-at least few percentages since all regular expression operations would
-be done in full UTF-8. But if you want to try this, add
--DUSE_UTF8_SCRIPTS to your compilation flags.
+The old perltodo notes "With C<gdb>, you can attach the debugger to a running
+program if you pass the process ID. It would be good to do this with the Perl
+debugger on a running Perl program, although I'm not sure how it would be done."
+ssh and screen do this with named pipes in tmp. Maybe we can too.
-=head2 Unicode collation and normalization
+=head2 A decent benchmark
-The Unicode::Collate and Unicode::Normalize modules
-by SADAHIRO Tomoyuki have been included since 5.8.0.
+perlbench seems impervious to any recent changes made to the perl core. It would
+be useful to have a reasonable general benchmarking suite that roughly
+represented what current perl programs do, and measurably reported whether
+tweaks to the core improve, degrade or don't really affect performance, to
+guide people attempting to optimise the guts of perl.
- Collation? http://www.unicode.org/unicode/reports/tr10/
- Normalization? http://www.unicode.org/unicode/reports/tr15/
+=head2 readpipe(LIST)
-=head2 pack/unpack tutorial
+system() accepts a LIST syntax (and a PROGRAM LIST syntax) to avoid
+running a shell. readpipe() (the function behind qx//) could be similarly
+extended.
-Wolfgang Laun finished what Simon Cozens started.
+=head2 Self ties
-=cut
+self ties are currently illegal because they caused too many segfaults. Maybe
+the causes of these could be tracked down and self-ties on all types re-
+instated.
https://perl5.git.perl.org / perl5.git / blobdiff