     return r
   }
 
-  func matchWhileAlphaDigit(consume: Bool = false) -> Int {
+  mutating func matchWhileAlphaDigit(consume: Bool = false) -> Int {
     var r = -1
     var i = currentIndex
     let savei = i

    return r
  }

  func eatWhileOne(c: UInt8) -> Bool {
    return matchWhileOne(c, consume: true) >= 0
  }

  func matchWhileOne(c: UInt8, consume: Bool = false) -> Int {
    var r = -1
    var i = currentIndex
    let savei = i

    return r
  }

  mutating func matchWhileDigit(consume: Bool = false) -> Int {
    var r = -1
    var i = currentIndex
    let savei = i
