http://www.perlmonks.org?node_id=1014279

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

Hello dear Monks,

Today I've encountered a problem which, really, drives me crazy.
Here is a small portion of the code which illustrates my issue:
#!/usr/bin/perl use 5.010; use strict; use warnings; use re 'eval'; sub make_esc_delim { my ($delim) = @_; return qr{\Q$delim\E[^$delim\\]*+(?>\\.|[^$delim\\]+)*\Q$delim\E}s +; } my $str_dq = make_esc_delim(q{"}); my %bpairs; { local $" = q{}; foreach my $d ([qw~< >~], [qw~( )~], [qw~{ }~], [qw~[ ]~]) { my @ed = map {quotemeta} @{$d}; $bpairs{$d->[0]} = qr{ $ed[0] (?<content> (?> (??{$bpairs{$d->[0]}}) (?{print "After eval!\n"}) | (?> $str_dq | [^@ed] ) )* ) $ed[1] }xs; } } my $x = q~func{{xx|"}"} @{d}end}~; if($x =~ /$bpairs{'{'}/){ print "First matched: $&\n"; } if($x =~ /func$bpairs{'{'}/){ # here is the problem print "Second matched: $&\n"; }
Output:
After eval! After eval! First matched: {{xx|"}"} @{d}end} Global symbol "$d" requires explicit package name at (re_eval 9) line +1. Compilation failed in regexp at test.pl line 43.

The question is: why perl doesn't let me to add some text around the compiled regex that embeds reevaluation of itself?
Should I consider this a bug?
Is there any other way around this issue?

Currently, I'm using: perl 5, version 16, subversion 2 (v5.16.2) built for i686-linux-thread-multi

Thank you very much.