Re: defined(@arr), defined (%hash)

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Re: defined(@arr), defined (%hash)

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From:

Matthew Horsfall

Date:

November 22, 2011 07:08

Subject:

Re: defined(@arr), defined (%hash)

Message ID:

CAJ0K8bjyiRKKx7uNFRjHfGH1hMkNL9QBTOiwppQRwP47_XB-9w@mail.gmail.com

On Tue, Nov 22, 2011 at 8:23 AM, Ricardo Signes
<perl.p5p@rjbs.manxome.org>wrote:

> ...but:
>
>  perl -E'use warnings; defined(our @a)'
>  (no deprecation)
>
> (package hashes are still deprecated)
>
>
Actually, it gets weirder:

  perl -we 'print defined(%hash = ())'
  defined(@array) is deprecated at -e line 1.
          (Maybe you should just omit the defined()?)

OP_RV2AV is explicitly ignored, but I don't quite follow the reason, and
OP_AASSIGN incorrectly catches %hash = () as @array = ()...

OP *
Perl_ck_defined(pTHX_ OP *o)            /* 19990527 MJD */
{
    PERL_ARGS_ASSERT_CK_DEFINED;

    if ((o->op_flags & OPf_KIDS)) {
        switch (cUNOPo->op_first->op_type) {
        case OP_RV2AV:
            /* This is needed for
               if (defined %stash::)
               to work.   Do not break Tk.
               */
            break;                      /* Globals via GV can be undef */
        case OP_PADAV:
        case OP_AASSIGN:                /* Is this a good idea? */
            Perl_ck_warner_d(aTHX_ packWARN(WARN_DEPRECATED),
                           "defined(@array) is deprecated");
            Perl_ck_warner_d(aTHX_ packWARN(WARN_DEPRECATED),
                           "\t(Maybe you should just omit the
defined()?)\n");

-- Matthew Horsfall (alh)

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