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Re: [perl #80628] [PATCH] __SUB__

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December 13, 2010 10:03
Re: [perl #80628] [PATCH] __SUB__
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On 13 December 2010 17:33, Zefram <> wrote:
> Given that (a) there are already multiple versions of this on CPAN,
> (b) there are competing versions of the semantics, and (c) it's easy
> to implement a new version on CPAN where the existing versions don't
> provide the desired semantics, it seems to me that the right place for
> this isn't the core, it's CPAN.

Personally I think that Scalar::Util, Data::Alias and friends taught
us the lesson that the above are poor justifications to argue that
something should be on CPAN or be part of core.

The reasons I see for putting it in core are: a) it needs XS to be
implemented, b) the XS would be maintained by the core dev team, c) by
putting it in core we guarantee to our users that a very useful
feature will always be available in perls following it, d) it replaces
an extremely awkward recipe that involves a module (Scalar::Util) that
after much debate and gnashing of teeth pretty much all agreed should
have been in core in the first place - repeating such an error with a
replacement for one of Scalar::Utils routines seems most illogical.

With a CPAN module there is no contract between Perl and the community
that something will be reliably available.

A CPAN module on the other may fall out of sync with perl and be
abandoned by its author or otherwise go unsupported. We have seen this
with Data::Alias.

We have also seen that in many environments it is anywhere from nearly
impossible to quite difficult to get non-standard modules installed at
all, let alone ones that require compiling XS code. We have seen both
of these problems with Scalar::Util. (I have personal experience of
this one.)

This is a language feature that allows us to do something that is
definitely non-trivial, useful, and likely to be widely adopted. It
should BE part of the language, not a nice-to-have after market


perl -Mre=debug -e "/just|another|perl|hacker/"

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