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Journal of rafael (2125)

Thursday February 13, 2003
07:39 AM

The treetops of a bad neighbourhood

[ #10560 ]
Have I already mentioned here how much I dislike pseudo-hashes ? From perlref (5.8.0), we read : you may use an array reference in some contexts that would normally require a hash reference. That means that if you have mistakenly used an array ref where a hash ref was expected, (especially in the middle of a large and complex data structure, that's funnier), this may silently go very wrong (as perl doesn't even warn you that you're using a pseudo-hash). In my case, this meant two hours hunting down a Out of memory! / Callback called exit error.

(I think Jarkko added a deprecation warning for pseudo-hashes in 5.8.1-to-be, but I'm not sure.)

-- Title of this journal entry by David King (Happy Apple)

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  • yes, indeed (Score:3, Informative)

    by jhi (318) <> on 2003.02.13 9:12 (#16984) Homepage Journal

    kosh:/tmp/jhi/maint ; /p/bin/perl -wle '$a=[{foo=>1,bar=>2},"FOO","BAR"];print $a->{foo}'
    kosh:/tmp/jhi/maint ; ./perl -wle '$a=[{foo=>1,bar=>2},"FOO","BAR"];print $a->{foo}'
    Pseudo-hashes are deprecated at -e line 1.
    kosh:/tmp/jhi/maint ;

    It's the dereferencing of pseudo-hashes that triggers the warning.

  • ____________________________________________________________________________
    [ 17725] By: hv                                    on 2002/08/17  00:51:19
            Log: Subject: [PATCH] Remove pseudo-hashes (complete)
                 From: Michael G Schwern <>
                 Date: Tue, 6 Aug 2002 13:05:10 -0700 (21: