eff_i_g has asked for the wisdom of the Perl Monks concerning the following question:

Monks,

According to the docs for %- and %+ they both allow "access to the named capture buffers, should they exist, in the last successful match" and they differ in that %- "associates a reference to an array containing the list of values captured by all buffers with that name (should there be several of them)" and %+ does not.

Yet, as seen below, %+ does not report all of the captures. Am I misunderstanding something or is this buggy behavior?

Code: 
use Data::Dumper;
'12' =~ /
    (?<twelve>
        (?<one>1)
        (?<two>2)
    )
/x;
print "All accounted for:\n";
print Dumper(\%-);
print "Here too:\n";
print Dumper([$1, $2, $3]);
print "Where are one and two?\n";
print Dumper(\%+);

[download]
Output: 
All accounted for:
$VAR1 = {
          'one' => [
                     '1'
                   ],
          'twelve' => [
                        '12'
                      ],
          'two' => [
                     '2'
                   ]
        };
Here too:
$VAR1 = [
          '12',
          '1',
          '2'
        ];
Where are one and two?
$VAR1 = {
          'twelve' => '12'
        };

[download]

Replies are listed 'Best First'.
Re: Inconsistent captures in %+ and %-
by toolic (Bishop) on Oct 22, 2010 at 20:18 UTC
    I don't get the same output as you do. Here is what I get: 
    All accounted for:
$VAR1 = {
          'one' => [
                     '1'
                   ],
          'twelve' => [
                        '12'
                      ],
          'two' => [
                     '2'
                   ]
        };
Here too:
$VAR1 = [
          '12',
          '1',
          '2'
        ];
Where are one and two?
$VAR1 = {
          'one' => '1',
          'twelve' => '12',
          'two' => '2'
        };

    [download]

    What version of perl are you using? I'm on v5.10.1, MSWin32-x86-multi-thread.

[reply]
[d/l]
[select]
      Ah! Many thanks toolic! I'm "perl, v5.10.0 built for sun4-solaris."
[reply]
        It must have been a bug which was subsequently fixed. I can reproduce your results with: 
        This is perl, v5.10.0 built for x86_64-linux

        [download]
        but not with: 
        This is perl 5, version 12, subversion 0 (v5.12.0) built for x86_64-li
+nux

        [download]
[reply]
[d/l]
[select]
        If you think you have found a bug in perl, always test it against the most recent version - it may have already been fixed (as in this case). 5.10.0 may look new and shiny to a lot of people, but it's just 2 months shy of being 3 years old. And 5.10.1, 5.12.0, 5.12.1, and 5.12.2 have been released since.
[reply]
Re: Inconsistent captures in %+ and %-
by fod (Friar) on Oct 22, 2010 at 20:22 UTC
    I'm getting the same (as toolic) on v5.12.2
[reply]

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