This Week on perl5-porters (9-15 February 2004)
Another quiet week on perl5-porters; but big patches were proposed,
demonstrating that the porters are not dead yet. Read about a revamp of
the parser, an in-depth modification of the internals, and other bugs
and associated fixes.
Revamping the perl parser
While fixing bug #25824, Dave Mitchell thought it would be a good idea
to shave the yacc and to move the perl parser implementation from byacc
to bison. And so did he. He noticed also that "the new bison parser
actually seems to be better at error recovery". Byacc is still used for
a2p, though.
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-02/msg00331.html
While he was at it, Dave added a verbose flag to the "-Dp" debugging
command-line option to perl ("-Dpv"), to display the top 8 elements of
the LR parser stack at each reduce.
Assigning globs to lvalues
Tassilo von Parseval is trying to fix a long standing bug : you can't,
currently, assign a glob to a lvalue (e.g. an element of a tied hash.)
The primary cause of the bug is that you can't upgrade, technically
speaking, a PVLV to hold a GV. He proposed a first patch with a rather
hackish approach, but Dave Mitchell raised the opinion that "the only
sane solution is to expand the PVLV structure so that it can incorporate
all the fields of a PVGV." Tassilo then proposed a second patch to
implement this. This last patch modifies the order in which the
different types of SV are upgraded in the core.
http://groups.google.com/groups?selm=20040214110256.GA14993%40ethan
BigInt bugs and fixes
Tels released Math::BigInt 1.70 and Math::BigRat 0.12. As of this
writing, it's yet unclear whether it fully fixes bug #26559 (problems
with big integers and the & bitwise operator), bug #26522 (some weird
overload-related problem, if I understand correctly), and bug #26508
(problem with the power of a negative big integer.) Those bugs are
described here :
http://groups.google.com/groups?selm=rt-3.0.8-26508-77180.15.818688458454%40perl.org
http://groups.google.com/groups?selm=rt-3.0.8-26522-77237.7.75701084030025%40perl.org
http://groups.google.com/groups?selm=rt-3.0.8-26522-77237.7.75701084030025%40perl.org
Stacked filetest operators
Rafael checked in bleadperl a patch (which he proposed a while ago) to
implement a little bit of syntactic sugar for chains of filetest
operators; it renders the combined expression "-f -w -x $file"
equivalent to "-x $file && -w _ && -f _".
http://groups.google.com/groups?selm=20040209231251.5988eb2c.rgarciasuarez%40free.fr
In Brief
Dominic Dunlop proposed to remove the support for the obsolescent
MachTen operating system. Perl 5.8.x doesn't compile anymore on MachTen,
anyway.
Wolfgang Loch reported (bug #26587) that File::Find used to clobber $_.
This was fixed recently, by adding a local($_) at the appropriate
place; but Mark-Jason Dominus points out that this is still a potential
bug, and needs to be a local(*_).
http://groups.google.com/groups?selm=rt-3.0.8-26587-77915.4.38321984527676%40perl.org
About this summary
This summary was written by Rafael Garcia-Suarez. Weekly summaries are
published on http://use.perl.org/ and posted on a mailing list, which
subscription address is [EMAIL PROTECTED] Corrections
and comments are welcome.
