This Week on perl5-porters (13-19 January 2003)
Another week, and its load of patches. A major evolution of the UTF8
implementation, some experimental surgery on the debugger, weak hashes,
strong pack templates, Win32 modules and quite a number of new ideas are
summarized in this week's summary.
The UTF8 patch
Jarkko Hietaniemi solved the problems pertaining UTF8 locales that I
summarized last week (see bug #19743). If I understand correctly :
The newest version of Encode (1.84, released by Dan Kogai last week) now
reports malformed data read from an UTF8 filehandle.
Moreover, the -C command-line switch is now required to enable
UTF8-ification of I/O. It no longer occurs automatically (and silently)
when perl is run under an UTF8 locale. Another way to achieve this is to
set the environment variable PERL_UTF8_LOCALE. (Running smoke tests with
this variable set and with an UTF8 locale would be a good idea.)
(PS: hijacking -C doesn't mean that wide system calls are to be dropped
on Windows. Gurusamy Sarathy said that he'll look at them in the
future.)
http:[EMAIL PROTECTED]/msg90835.html
Strange modulus failure
Abigail's smoke tests on Linux show a regular failure on a regression
test concerning integer modulus, when perl is compiled with 64 bit
capability. Other people are unable to reproduce it, so we may start to
blame the glibc or something.
http:[EMAIL PROTECTED]/msg90917.html
Debugger performance degradation
Bug #20218, reported by Dirk Koopman, demonstrates that the debugger is
ten times slower (under some circumstances) in perl 5.8.0 than in perl
5.6.1.
http:[EMAIL PROTECTED]/msg90866.html
Jarkko Hietaniemi then found a single one-line change that is to be
blamed for a large part of this slowdown. The discussion continues...
http:[EMAIL PROTECTED]/msg90985.html
Weak hashes
Mark Mielke asked for ways to implement weak hashes in Perl (i.e. hashes
that contain weak references, and from which keys are deleted when the
weak reference is collected.) Several alternatives were proposed.
http:[EMAIL PROTECTED]/msg90773.html
Work on pack()
Wolfgang Laun proposed a huge patch to the pack() and unpack()
functions, that fixes a lot of problems. He's still working on it, as
it's not perfect yet. On his to-do list is also defining "the syntax for
the template language". We're looking forward for it.
He posted a summary of the changes here :
http:[EMAIL PROTECTED]/msg90819.html
In brief
Rafael Kitover sent a huge set of patches for the libwin32 bundle, a
suite of Windows-specific modules, maintained on CPAN by Gurusamy
Sarathy.
Brent Dax proposed to add a new prototype to mimic the delete() built-in
(i.e. define a function that takes an hash/array slice/element as
argument.) Rafael Garcia-Suarez answered that this is possible, but not
trivial.
Paul Marquess says that he's "almost finished putting a module together,
called DBM_Filter, that builds on the existing DBM Filter hooks, but
makes it easer to write DBM Filters and to stack multiple filters." This
is intended to allow writing encoding filters for the ".*DBM?_File"
modules. He asks whether this module should go in the core. Nobody
commented.
The same bug was reported as #20154 and #20357 : a case of coredump
caused by goto() inside a "do/while" or a "for" loop.
Nicholas Clark had a damn good idea about optimizing the entersub op
(executed when a subroutine is called.)
http:[EMAIL PROTECTED]/msg90802.html
Campo Weijerman remarked that isa() doesn't work on magic variables.
This was promptly fixed.
Ton Hospel continues to report obscure bugs. (bug #20321, "indexing the
result of a listcontext match inside a string interpolation looses
values".)
Jason Lee notes that %lf is not recognized by perl 5.8.0 in a printf()
format. This is apparently not the right thing. (bug #20339.)
Dave Rolsky asked if it was possible to call perl's regex engine from XS
code. Nick Ing-Simmons provided an answer (and a few hints) : it's
indeed possible, but "tricky and risky", as there is no clean external
interface to the regex engine.
Alan Burlison advertised his newest creation, Solaris-PerlGcc (found on
CPAN), that allows to compile modules against the perl shipped with
Solaris, with the gcc compiler.
About this summary
This summary brought to you by Rafael Garcia-Suarez. Summaries are
available on http://use.perl.org/ and/or via a mailing list, which
subscription address is [EMAIL PROTECTED] Comments and
corrections are welcome.
