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Postings from November 1999
Ronald J Kimball <rjk@linguist.dartmouth.edu> wrote:
>On Sun, Nov 21, 1999 at 04:52:21AM -0500, Sean McAfee wrote:
>> The perldiag man page includes the following paragraph:
>> Can't use an undefined value as %s reference
>> (F) A value used as either a hard reference or a
>> symbolic reference must be a defined value. This helps
>> to delurk some insidious errors.
>> In fact, it appears that this is only a fatal error when strict refs is in
>> effect. It's not an error at all, otherwise.
>~> perl
>no strict;
>undef->[1];
>Can't use an undefined value as an ARRAY reference at - line 2.
Guess I should have included a code sample. Sorry about the oversight.
bash-2.03$ perl -le '$x = undef; print @$x'
bash-2.03$ perl -le 'use strict; my $x = undef; print @$x'
Can't use an undefined value as an ARRAY reference at -e line 1.
bash-2.03$
Here's the essential part of the code which originally brought the behavior
to my attention:
use strict;
my (@result, %id, %dup);
%id = ( 1 => 'a', 2 => 'b', 3 => 'c');
%dup = ( 2 => [ 'x', 'y', 'z' ] );
@result = map +($id{$_}, @{ $dup{$_} }), 1, 2, 3;
I got the above error until I preceded the last line with "no strict 'refs'".
--
Sean McAfee | GCS d->-- s+++: a27 C++ US+++ P+++$ L++ E- W+ N++ |
| K w--- O? M- V-- PS+ PE Y+ PGP?>++ t+() 5++ X R+ | mcafee@
| tv+ b++ DI++ D+ G e++ h r---* y+>++ | umich.edu
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