http://www.perlmonks.org?node_id=582107


in reply to Re^2: Extraneous behaviour of match variables
in thread Extraneous behaviour of match variables

(?:(?<!video).)+ is wrong.

for my $re ( qr/"(?:(?!video).)+"/, qr/"(?:(?<!video).)+"/, qr/"(?:.(?<!video))+"/, ) { print("$re\n"); for ( '"...video..."', '"...video"', '"video..."', '"video"', ) { print("$_: ", /$re/?1:0, "\n"); } }
(?-xism:"(?:(?!video).)+") "...video...": 0 "...video": 0 "video...": 0 "video": 0 (?-xism:"(?:(?<!video).)+") "...video...": 0 "...video": 1 <----- XXX "video...": 0 "video": 1 <----- XXX (?-xism:"(?:.(?<!video))+") "...video...": 0 "...video": 0 "video...": 0 "video": 0

(?:(?!video).)+ and (?:.(?<!video))+ should be equivalent. You can do benchmarks to be sure.