For a 2n-by-n-digit division, this algorithm runs a 4-by-2 long division over
wide digits, producing two wide digits plus a possible leading regular digit 1,
which can be handled without a recursive call. That is, the algorithm uses two
full iterations, each using an n-by-n/2-digit division and an n/2-by-n/2-digit
multiplication, along with a few n-digit additions and subtractions. The standard

// that is not a valid radix point or digit.
//
//	number    = mantissa | prefix pmantissa .
//	prefix    = "0" [ "b" | "B" | "o" | "O" | "x" | "X" ] .
//	mantissa  = digits "." [ digits ] | digits | "." digits .
//	pmantissa = [ "_" ] digits "." [ digits ] | [ "_" ] digits | "." digits .
//	digits    = digit { [ "_" ] digit } .
//	digit     = "0" ... "9" | "a" ... "z" | "A" ... "Z" .
//

        "regex": "^listener(?=\\.).*?\\.http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "http_conn_manager_prefix",
        "regex": "^http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "listener_address",
        "regex": "^listener\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {

        "regex": "^listener(?=\\.).*?\\.http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "http_conn_manager_prefix",
        "regex": "^http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "listener_address",
        "regex": "^listener\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {

        "regex": "^listener(?=\\.).*?\\.http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "http_conn_manager_prefix",
        "regex": "^http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "listener_address",
        "regex": "^listener\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {

        "regex": "^listener(?=\\.).*?\\.http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "http_conn_manager_prefix",
        "regex": "^http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "listener_address",
        "regex": "^listener\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {

        "regex": "^listener(?=\\.).*?\\.http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "http_conn_manager_prefix",
        "regex": "^http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "listener_address",
        "regex": "^listener\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {

        "regex": "^listener(?=\\.).*?\\.http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "http_conn_manager_prefix",
        "regex": "^http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "listener_address",
        "regex": "^listener\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {

			for n>>k == 0 {
				n = n * 10
				r++
			}
			break
		}
		c := uint(a.d[r])
		n = n*10 + c - '0'
	}
	a.dp -= r - 1

	var mask uint = (1 << k) - 1

	// Pick up a digit, put down a digit.
	for ; r < a.nd; r++ {
		c := uint(a.d[r])
		dig := n >> k
		n &= mask
		a.d[w] = byte(dig + '0')
		w++
		n = n*10 + c - '0'
	}

	// Put down extra digits.
	for n > 0 {

        "regex": "^listener(?=\\.).*?\\.http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "http_conn_manager_prefix",
        "regex": "^http\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {
        "tag_name": "listener_address",
        "regex": "^listener\\.(((?:[_.[:digit:]]*|[_\\[\\]aAbBcCdDeEfF[:digit:]]*))\\.)"
      },
      {