This Week on perl5-porters (1-7 December 2003)

This Week on perl5-porters (1-7 December 2003)

  "I like tie" could be the summary of this week's summary. But it would
  be a bit terse, wouldn't it ? Read on for the details.

Tied hashes and scalar context
  This was the highest volume topic this week. Rafael pointed out that
  tied hashes in scalar context always return 0 with perl <= 5.8.2, which
  is obviously not a good thing ; and with perl 5.9.0 using a hash in
  scalar context yields a fatal error, which has the benefit of not
  returning a wrong value, but which is not backwards-compatible and most
  inconvenient. So he called for action.

      http://groups.google.com/groups?threadm=20031203022335.39c35723.rgarciasuarez%40free.fr

  Tassilo von Parseval proposed to add a SCALAR() method to tied hashes,
  to be called when a hash is used in scalar context. When the class the
  hash is tied to doesn't provide this method, perl could try to make some
  educated guesses. For example, if the hash is in the middle of an
  iteration, this means that it isn't empty. Thus perl could return a true
  value to indicate this. Moreover, if the hash is not iterating, perl
  could call FIRSTKEY() if it can't find SCALAR(). The base class
  Tie::StdHash could include a default implementation of SCALAR(). Tassilo
  provided a patch, which got applied.

  Yitzchak Scott-Thoennes spots a minor gotcha though : removing the last
  element from a hash will leave the iterator set. So, should scalar(%h)
  reset %h's iterator ? or implement a smarter fall-back strategy ?
  Tassilo decided to document this fact for now.

      http://groups.google.com/groups?threadm=20031207025958.GA2700%40efn.org

Extending the tied scalar interface
  Tassilo also proposed to add a SUBSTR method to tied scalars. Dave
  Mitchell remembered the old problem about new optional tie methods, that
  they don't play well with inheritance and backwards compatibility.
  Michael Schwern and Elizabeth Mattijsen suggest to wait for Ponie and
  its underlying Parrot vtables to clean up the mess.

      http://groups.google.com/groups?threadm=20031204100156.GA15074%40ethan

CLONEing
  Stas Bekman is working on a piece of documentation about the CLONE()
  method; more specifically, on a full-fledged example aimed at CLONE()
  method authors. While doing so, he remarked a problem with XS functions
  called from CLONE() methods, on perl 5.8.2 and later : they receive the
  arguments to "threads->new()". This problem is avoided if the XS module
  defines PERL_NO_GET_CONTEXT.

      http://groups.google.com/groups?threadm=3FCDAC86.8070907%40stason.org

In Brief
  Leon Brocard released the first snapshot of perl 5.005_04-to-be.

      http://groups.google.com/groups?threadm=20031205170609.GA29131%40kanga.astray.com

  A remark of Nick-Ing Simmons about a compilation issue in Tk led to a
  discussion of advantages of C inline functions vs CPP macros. Macros
  won.

      http://groups.google.com/groups?threadm=20031201192441.17478.2%40llama.elixent.com

  Arjen Bax reports that localtime() doesn't seem to take into account the
  timezone under Cygwin with perl 5.8.2. (Bug #24582.)

  Matthias Ulrichs manages to produce a "Bizarre ARRAY copy" error with a
  small program, running under perl 5.8.2 + threads. (Bug #24589.)

  Randal L. Schwartz reports a bug in CGI::Carp : it doesn't seem to ever
  output a header. Lincoln Stein says it's already fixed in his
  development copy.

      http://groups.google.com/groups?threadm=86u14hzkwo.fsf%40blue.stonehenge.com

  Alberto Manuel Brandão Simões has problems with using DB_File and UTF-8
  keys from an UTF-8 source script. Roman Vasicek suggests to use a DBM
  filter.

      http://groups.google.com/groups?threadm=1070484684.714.1.camel%40holst.di.uminho.pt

  Rafael Garcia-Suarez and Arthur Bergman provided some more comments
  about how and when CHECK and INIT blocks are run, discussing the
  possibility of adding a new kind of block, START.

      http://groups.google.com/groups?threadm=p05111b03bbf3754332ec%40[192.168.56.3]

  Tels pre-released Math::BigInt 1.67.

      http://groups.google.com/groups?threadm=200312062016.50484%40bloodgate.com

  Thomas Klausner anounced the release of Module-CPANTS-Generator 0.010,
  "a framework to test all distributions on CPAN for 'kwalitee'."

      http://groups.google.com/groups?threadm=20031205205548.GB1578%40zsi.at

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.