I assume that you have read perlre, and the warning there that (??{ ... }) is highly experimental. It's not there without a reason.

I noticed that even a simple regex in a (??{...}) block doesn't work: 

#!/usr/bin/perl
use strict;
use warnings;

$_ = "foo";

print "a" =~ m{.} ? "o\n" : "O\n";

if ( m/f (??{ "a" =~ m{.} ? 'o' : 'O' }) o/x){
    print "matched\n"
}
__END__
o

[download]

In your position I'd precompute the regex instead of trying to stuff it all in one line.

In reply to Re: Can "delayed-regex assertions" be nested... by moritz
in thread Can "delayed-regex assertions" be nested... by ddn123456

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