This is the revision history for learn balanced parentheses in <matrix.org:#rAnyijhRxzFRfdjSHl:matrix.org>

factoid_idsubjectcopulapredicateauthornamespace
3613 learn balanced parentheses is print "OK" if /^(?{local $d=0})(\((?{$d++})|\)(?{$d--})(?(?{$d<0})(?!))|(?>[^()]+))*(?(?{$d!=0})(?!))$/' prints "OK" if, and only if, $_ has proprely balanced parentheses perlbot <*:##NULL>