Matching REx "(?:(.)b|.)+" against "ac"
   0 <> <ac>                 |  1:CURLYX[0] {1,32767}(15)
   0 <> <ac>                 | 14:  WHILEM[1/1](0)
                                    whilem: matched 0 out of 1..32767
   0 <> <ac>                 |  3:    BRANCH(11)
   0 <> <ac>                 |  4:      OPEN1(6)
   0 <> <ac>                 |  6:      REG_ANY(7)
   1 <a> <c>                 |  7:      CLOSE1(9)