PERLTODO(1) Perl Programmers Reference Guide PERLTODO(1)NAMEperltodo - Perl TO-DO List
DESCRIPTION
This is a list of wishes for Perl. It is maintained by
Nathan Torkington for the Perl porters. Send updates to
perl5-porters@perl.org. If you want to work on any of
these projects, be sure to check the perl5-porters
archives for past ideas, flames, and propaganda. This
will save you time and also prevent you from implementing
something that Larry has already vetoed. One set of
archives may be found at:
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/
Infrastructure
Mailing list archives
Chaim suggests contacting egroup and asking them to
archive the other perl.org mailing lists. Probably not
advocacy, but definitely perl6-porters, etc.
Bug tracking system
Richard Foley richard@perl.org is writing one. We looked
at several, like gnats and the Debian system, but at the
time we investigated them, none met our needs. Since
then, Jitterbug has matured, and may be worth reinvestiga
tion.
The system we've developed is the recipient of perlbug
mail, and any followups it generates from perl5-porters.
New bugs are entered into a mysql database, and sent on to
perl5-porters with the subject line rewritten to include a
"ticket number" (unique ID for the new bug). If the
incoming message already had a ticket number in the sub
ject line, then the message is logged against that bug.
There is a separate email interface (not forwarding to
p5p) that permits porters to claim, categorize, and close
tickets.
There is also a web interface to the system at
http://bugs.perl.org.
The current delay in implementation is caused by perl.org
lockups. One suspect is the mail handling system, possi
bly going into loops.
We still desperately need a bugmaster, someone who will
look at every new "bug" and kill those that we already
know about, those that are not bugs at all, etc.
Regression Tests
The test suite for Perl serves two needs: ensuring fea
tures work, and ensuring old bugs have not been reintro
duced. Both need work.
Brent LaVelle (lavelle@metronet.com) has stepped forward
to work on performance tests and improving the size of the
test suite.
Coverage
Do the tests that come with Perl exercise every line
(or every block, or ...) of the Perl interpreter, and
if not then how can we make them do so?
Regression
No bug fixes should be made without a corresponding
testsuite addition. This needs a dedicated enforcer,
as the current pumpking is either too lazy or too
stupid or both and lets enforcement wander all over
the map. :-)
__DIE__
Tests that fail need to be of a form that can be read
ily mailed to perlbug and diagnosed with minimal back-
and-forth's to determine which test failed, due to
what cause, etc.
suidperl
We need regression/sanity tests for suidperl
The 25% slowdown from perl4 to perl5
This value may or may not be accurate, but it cer
tainly is eye-catching. For some things perl5 is
faster than perl4, but often the reliability and
extensibility have come at a cost of speed. The
benchmark suite that Gisle released earlier has been
hailed as both a fantastic solution and as a source of
entirely meaningless figures. Do we need to test
"real applications"? Can you do so? Anyone have
machines to dedicate to the task? Identify the things
that have grown slower, and see if there's a way to
make them faster.
Configure
Andy Dougherty maintain(ed|s) a list of "todo" items for
the configure that comes with Perl. See Porting/pump
kin.pod in the latest source release.
Install HTML
Have "make install" give you the option to install HTML as
well. This would be part of Configure. Andy Wardley
(certified Perl studmuffin) will look into the current
problems of HTML installation--is 'installhtml' preventing
this from happening cleanly, or is pod2html the problem?
If the latter, Brad Appleton's pod work may fix the prob
lem for free.
Perl Language
64-bit Perl
Verify complete 64 bit support so that the value of
sysseek, or "-s", or stat(), or tell can fit into a perl
number without losing precision. Work with the perl-64bit
mailing list on perl.org.
Prototypes
Named prototypes
Add proper named prototypes that actually work use
fully.
Indirect objects
Fix prototype bug that forgets indirect objects.
Method calls
Prototypes for method calls.
Context
Return context prototype declarations.
Scoped subs
lexically-scoped subs, e.g. my sub
Perl Internals
magic_setisa
"magic_setisa" should be made to update %FIELDS [???]
Garbage Collection
There was talk of a mark-and-sweep garbage collector at
TPC2, but the (to users) unpredictable nature of its
behaviour put some off. Sarathy, I believe, did the work.
Here's what he has to say:
Yeah, I hope to implement it someday too. The points that
were raised in TPC2 were all to do with calling DESTROY()
methods, but I think we can accommodate that by extending
bless() to stash extra information for objects so we track
their lifetime accurately for those that want their
DESTROY() to be predictable (this will be a speed hit,
naturally, and will therefore be optional, naturally. :)
[N.B. Don't even ask me about this now! When I have the
time to write a cogent summary, I'll post it.]
Reliable signals
Sarathy and Dan Sugalski are working on this. Chip posted
a patch earlier, but it was not accepted into 5.005. The
issue is tricky, because it has the potential to greatly
slow down the core.
There are at least three things to consider:
Alternate runops() for signal despatch
Sarathy and Dan are discussed this on perl5-porters.
Figure out how to die() in delayed sighandler
Add tests for Thread::Signal
Automatic tests against CPAN
Is there some way to automatically build all/most of
CPAN with the new Perl and check that the modules
there pass all the tests?
Interpolated regex performance bugs
while (<>) {
$found = 0;
foreach $pat (@patterns) {
$found++ if /$pat/o;
}
print if $found;
}
The qr// syntax added in 5.005 has solved this problem,
but it needs more thorough documentation.
Memory leaks from failed eval/regcomp
The only known memory leaks in Perl are in failed code or
regexp compilation. Fix this. Hugo Van Der Sanden will
attempt this but won't have tuits until January 1999.
Make XS easier to use
There was interest in SWIG from porters, but nothing has
happened lately.
Make embedded Perl easier to use
This is probably difficult for the same reasons that "XS
For Dummies" will be difficult.
Namespace cleanup
CPP-space: restrict CPP symbols exported from headers
header-space: move into CORE/perl/
API-space: begin list of things that constitute public api
env-space: Configure should use PERL_CONFIG instead of CONFIG etc.
MULTIPLICITY
Complete work on safe recursive interpreters
"Perl->new()". Sarathy says that a reference implementa
tion exists.
MacPerl
Chris Nandor and Matthias Neeracher are working on better
integrating MacPerl into the Perl distribution.
Documentation
There's a lot of documentation that comes with Perl. The
quantity of documentation makes it difficult for users to
know which section of which manpage to read in order to
solve their problem. Tom Christiansen has done much of
the documentation work in the past.
A clear division into tutorial and reference
Some manpages (e.g., perltoot and perlreftut) clearly set
out to educate the reader about a subject. Other manpages
(e.g., perlsub) are references for which there is no tuto
rial, or are references with a slight tutorial bent. If
things are either tutorial or reference, then the reader
knows which manpage to read to learn about a subject, and
which manpage to read to learn all about an aspect of that
subject. Part of the solution to this is:
Remove the artificial distinction between operators and
functions
History shows us that users, and often porters, aren't
clear on the operator-function distinction. The present
split in reference material between perlfunc and perlop
hinders user navigation. Given that perlfunc is by far
the larger of the two, move operator reference into perl
func.
More tutorials
More documents of a tutorial nature could help. Here are
some candidates:
Regular expressions
Robin Berjon (r.berjon@ltconsulting.net) has volun
teered.
I/O Mark-Jason Dominus (mjd@plover.com) has an outline for
perliotut.
pack/unpack
This is badly needed. There has been some discussion
on the subject on perl5-porters.
Debugging
Ronald Kimball (rjk@linguist.dartmouth.edu) has volun
teered.
Include a search tool
perldoc should be able to 'grep' fulltext indices of
installed POD files. This would let people say:
perldoc -find printing numbers with commas
and get back the perlfaq entry on 'commify'.
This solution, however, requires documentation to contain
the keywords the user is searching for. Even when the
users know what they're looking for, often they can't
spell it.
Include a locate tool
perldoc should be able to help people find the manpages on
a particular high-level subject:
perldoc -find web
would tell them manpages, web pages, and books with mate
rial on web programming. Similarly "perldoc -find
databases", "perldoc -find references" and so on.
We need something in the vicinity of:
% perl -help random stuff
No documentation for perl function `random stuff' found
The following entry in perlfunc.pod matches /random/a:
=item rand EXPR
=item rand
Returns a random fractional number greater than or equal to C<0> and less
than the value of EXPR. (EXPR should be positive.) If EXPR is
omitted, the value C<1> is used. Automatically calls C<srand()> unless
C<srand()> has already been called. See also C<srand()>.
(Note: If your rand function consistently returns numbers that are too
large or too small, then your version of Perl was probably compiled
with the wrong number of RANDBITS.)
The following pod pages seem to have /stuff/a:
perlfunc.pod (7 hits)
perlfaq7.pod (6 hits)
perlmod.pod (4 hits)
perlsyn.pod (3 hits)
perlfaq8.pod (2 hits)
perlipc.pod (2 hits)
perl5004delta.pod (1 hit)
perl5005delta.pod (1 hit)
perlcall.pod (1 hit)
perldelta.pod (1 hit)
perlfaq3.pod (1 hit)
perlfaq5.pod (1 hit)
perlhist.pod (1 hit)
perlref.pod (1 hit)
perltoc.pod (1 hit)
perltrap.pod (1 hit)
Proceed to open perlfunc.pod? [y] n
Do you want to speak perl interactively? [y] n
Should I dial 911? [y] n
Do you need psychiatric help? [y] y
<PELIZA> Hi, what bothers you today?
A Python programmer in the next cubby is driving me nuts!
<PELIZA> Hmm, thats fixable. Just [rest censored]
Separate function manpages by default
Perl should install 'manpages' for every function/operator
into the 3pl or 3p manual section. By default. The
splitman program in the Perl source distribution does the
work of turning big perlfunc into little 3p pages.
Users can't find the manpages
Make "perldoc" tell users what they need to add to their
.login or .cshrc to set their MANPATH correctly.
Install ALL Documentation
Make the standard documentation kit include the VMS, OS/2,
Win32, Threads, etc information. installperl and
pod/Makefile should know enough to copy README.foo to
perlfoo.pod before building everything, when appropriate.
Outstanding issues to be documented
Tom has a list of 5.005_5* features or changes that
require documentation.
Create one document that coherently explains the delta
between the last camel release and the current release.
perldelta was supposed to be that, but no longer. The
things in perldelta never seemed to get placed in the
right places in the real manpages, either. This needs
work.
Adapt www.linuxhq.com for Perl
This should help glorify documentation and get more people
involved in perl development.
Replace man with a perl program
Can we reimplement man in Perl? Tom has a start. I
believe some of the Linux systems distribute a manalike.
Alternatively, build on perldoc to remove the unfeatures
like "is slow" and "has no apropos".
Unicode tutorial
We could use more work on helping people understand Perl's
new Unicode support that Larry has created.
Modules
Update the POSIX extension to conform with the POSIX
1003.1 Edition 2
The current state of the POSIX extension is as of Edition
1, 1991, whereas the Edition 2 came out in 1996. ISO/IEC
9945:1-1996(E), ANSI/IEEE Std 1003.1, 1996 Edition. ISBN
1-55937-573-6. The updates were legion: threads, IPC, and
real time extensions.
Module versions
Automate the checking of versions in the standard distri
bution so it's easy for a pumpking to check whether CPAN
has a newer version that we should be including?
New modules
Which modules should be added to the standard distribu
tion? This ties in with the SDK discussed on the perl-sdk
list at perl.org.
Profiler
Make the profiler (Devel::DProf) part of the standard
release, and document it well.
Tie Modules
VecArray
Implement array using vec(). Nathan Torkington has
working code to do this.
SubstrArray
Implement array using substr()
VirtualArray
Implement array using a file
ShiftSplice
Defines shift et al in terms of splice method
Procedural options
Support procedural interfaces for the common cases of
Perl's gratuitously OOO modules. Tom objects to "use
IO::File" reading many thousands of lines of code.
RPC
Write a module for transparent, portable remote procedure
calls. (Not core). This touches on the CORBA and ILU
work.
y2k localtime/gmtime
Write a module, Y2k::Catch, which overloads localtime and
gmtime's returned year value and catches "bad" attempts to
use it.
Export File::Find variables
Make File::Find export "$name" etc manually, at least if
asked to.
Ioctl
Finish a proper Ioctl module.
Debugger attach/detach
Permit a user to debug an already-running program.
Regular Expression debugger
Create a visual profiler/debugger tool that stepped you
through the execution of a regular expression point by
point. Ilya has a module to color-code and display regu
lar expression parses and executions. There's something
at http://tkworld.org/ that might be a good start, it's a
Tk/Tcl RE wizard, that builds regexen of many flavours.
Alternative RE Syntax
Make an alternative regular expression syntax that is
accessed through a module. For instance,
use RE;
$re = start_of_line()
->literal("1998/10/08")
->optional( whitespace() )
->literal("[")
->remember( many( or( "-", digit() ) ) );
if (/$re/) {
print "time is $1\n";
}
Newbies to regular expressions typically only use a subset
of the full language. Perhaps you wouldn't have to imple
ment the full feature set.
Bundled modules
Nicholas Clark (nick@flirble.org) had a patch for storing
modules in zipped format. This needs exploring and con
cluding.
Expect
Adopt IO::Tty, make it as portable as Don Libes' "expect"
(can we link against expect code?), and perfect a Perl
version of expect. IO::Tty and expect could then be dis
tributed as part of the core distribution, replacing
Comm.pl and other hacks.
GUI::Native
A simple-to-use interface to native graphical abilities
would be welcomed. Oh, Perl's access Tk is nice enough,
and reasonably portable, but it's not particularly as fast
as one would like. Simple access to the mouse's cut
buffer or mouse-presses shouldn't required loading a few
terabytes of Tk code.
Update semibroken auxiliary tools; h2ph, a2p, etc.
Kurt Starsinic is working on h2ph. mjd has fixed bugs in
a2p in the past. a2p apparently doesn't work on nawk and
gawk extensions. Graham Barr has an Include module that
does h2ph work at runtime.
pod2html
A short-term fix: pod2html generates absolute HTML links.
Make it generate relative links.
Podchecker
Something like lint for Pod would be good. Something that
catches common errors as well as gross ones. Brad Apple
ton is putting together something as part of his PodParser
work.
Tom's Wishes
Webperl
Design a webperl environment that's as tightly integrated
and as easy-to-use as Perl's current command-line environ
ment.
Mobile agents
More work on a safe and secure execution environment for
mobile agents would be neat; the Safe.pm module is a
start, but there's a still a lot to be done in that area.
Adopt Penguin?
POSIX on non-POSIX
Standard programming constructs for non-POSIX systems
would help a lot of programmers stuck on primitive, legacy
systems. For example, Microsoft still hasn't made a
usable POSIX interface on their clunky systems, which
means that standard operations such as alarm() and fork(),
both critical for sophisticated client-server programming,
must both be kludged around.
I'm unsure whether Tom means to emulate alarm( )and
fork(), or merely to provide a document like perlport.pod
to say which features are portable and which are not.
Portable installations
Figure out a portable semi-gelled installation, that is,
one without full paths. Larry has said that he's thinking
about this. Ilya pointed out that perllib_mangle() is
good for this.
Win32 Stuff
Rename new headers to be consistent with the rest
Sort out the spawnvp() mess
Work out DLL versioning
Style-check
Would be nice to have
""pack ""(stuff)*""""
Contiguous bitfields in pack/unpack
lexperl
Bundled perl preprocessor
Use posix calls internally where possible
format BOTTOM
-i rename file only when successfully changed
All ARGV input should act like <>
report HANDLE [formats].
support in perlmain to rerun debugger
lvalue functions
Tuomas Lukka, on behalf of the PDL project, greatly
desires this and Ilya has a patch for it (probably
against an older version of Perl). Tuomas points out
that what PDL really wants is lvalue methods, not just
subs.
Possible pragmas
(use less memory, CPU)
Optimizations
constant function cache
foreach(reverse...)
Cache eval tree
Unless lexical outer scope used (mark in &compiling?).
rcatmaybe
Shrink opcode tables
Via multiple implementations selected in peep.
Cache hash value
Not a win, according to Guido.
Optimize away @_ where possible
Optimize sort by { $a <=> $b }
Greg Bacon added several more sort optimizations. These
have made it into 5.005_55, thanks to Hans Mulder.
Rewrite regexp parser for better integrated optimization
The regexp parser was rewritten for 5.005. Ilya's the
regexp guru.
Vague possibilities
ref function in list context
This seems impossible to do without substantially
breaking code.
make tr/// return histogram in list context?
Loop control on do{} et al
Explicit switch statements
Nobody has yet managed to come up with a switch syntax
that would allow for mixed hash, constant, regexp
checks. Submit implementation with syntax, please.
compile to real threaded code
structured types
Modifiable $1 et al
The intent is for this to be a means of editing the
matched portions of the target string.
To Do Or Not To Do
These are things that have been discussed in the past and
roundly criticized for being of questionable value.
Making my() work on "package" variables
Being able to say my($Foo::Bar), something that sounds
ludicrous and the 5.6 pumpking has mocked.
"or" testing defined not truth
We tell people that "||" can be used to give a default
value to a variable:
$children = shift || 5; # default is 5 children
which is almost (but not):
$children = shift;
$children = 5 unless $children;
but if the first argument was given and is "0", then it
will be considered false by "||" and "5" used instead.
Really we want an "||"-like operator that behaves like:
$children = shift;
$children = 5 unless defined $children;
Namely, a "||" that tests defined-ness rather than truth.
One was discussed, and a patch submitted, but the objec
tions were many. While there were objections, many still
feel the need. At least it was decided that "??" is the
best name for the operator.
"dynamic" lexicals
my $x;
sub foo {
local $x;
}
Localizing, as Tim Bunce points out, is a separate concept
from whether the variable is global or lexical. Chip
Salzenberg had an implementation once, but Larry thought
it had potential to confuse.
"class"-based, rather than package-based "lexicals"
This is like what the Alias module provides, but the vari
ables would be lexicals reserved by perl at compile-time,
which really are indices pointing into the pseudo-hash
object visible inside every method so declared.
Threading
Modules
Which of the standard modules are thread-safe? Which CPAN
modules? How easy is it to fix those non-safe modules?
Testing
Threading is still experimental. Every reproducible bug
identifies something else for us to fix. Find and submit
more of these problems.
$AUTOLOAD
exit/die
Consistent semantics for exit/die in threads.
External threads
Better support for externally created threads.
Thread::Pool
thread-safety
Spot-check globals like statcache and global GVs for
thread-safety. "Part done", says Sarathy.
Per-thread GVs
According to Sarathy, this would make @_ be the same in
threaded and non-threaded, as well as helping solve prob
lems like filehandles (the same filehandle currently can
not be used in two threads).
Compiler
Optimization
The compiler's back-end code-generators for creating byte
code or compilable C code could use optimization work.
Byteperl
Figure out how and where byteperl will be built for the
various platforms.
Precompiled modules
Save byte-compiled modules on disk.
Executables
Auto-produce executable.
Typed lexicals
Typed lexicals should affect B::CC::load_pad.
Win32
Workarounds to help Win32 dynamic loading.
END blocks
END blocks need saving in compiled output, now that CHECK
blocks are available.
_AUTOLOAD
_AUTOLOAD prodding.
comppadlist
Fix comppadlist (names in comppad_name can have fake SvCUR
from where newASSIGNOP steals the field).
Cached compilation
Can we install modules as bytecode?
Recently Finished Tasks
Figure a way out of $^(capital letter)
Figure out a clean way to extend $^(capital letter) beyond
the 26 alphabets. (${^WORD} maybe?)
Mark-Jason Dominus sent a patch which went into 5.005_56.
Filenames
Keep filenames in the distribution and in the standard
module set be 8.3 friendly where feasible. Good luck
changing the standard modules, though.
Foreign lines
Perl should be more generous in accepting foreign line
terminations. Mostly done in 5.005.
Namespace cleanup
symbol-space: "pl_" prefix for all global vars
"Perl_" prefix for all functions
CPP-space: stop malloc()/free() pollution unless asked
ISA.pm
Rename and alter ISA.pm. Done. It is now base.pm.
gettimeofday
See Time::HiRes.
autocroak?
This is the Fatal.pm module, so any builtin that does not
return success automatically die()s. If you're feeling
brave, tie this in with the unified exceptions scheme.
2001-03-18 perl v5.6.1 PERLTODO(1)
