I'm testing out some experimental regex features (perlre/perlretut), and I'm wondering why this doesn't match 
for (
    '<1>', # want match
    '<<2>>', # want match
    '<<3>', # want fail
    '<<<4>>', # want fail
    '<<5>>>>', # want fail
    ){
  use vars qw' $LEN ';
  print "$_\n";
  print "  $_\n" for m(
(?<! < ) # no preceeding <
(?><+)(?{ $LEN = length $^N; })
( [^><]* )
(?(?{ $LEN > 0 })(??{ '>' x $LEN }))
(?! > )  # no following >
)x;
print "    LEN = $LEN\n";

}
__END__
<1>

    LEN = 0
<<2>>

    LEN = 0
<<3>

    LEN = 0
<<<4>>

    LEN = 0
<<5>>>>

    LEN = 0

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In reply to experimental regex (?(?{code}) conditional (??{ 'code' }) ) by Anonymous Monk

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