         return currentIndex >= characters.endIndex
     }
     
-    func resetTo(index: String.CharacterView.Index) {
+    func resetTo(index: String.Index) {
         currentIndex = index
     }
     

internal class TokenCharacterBuffer {
    private let characters: String.CharacterView
    private let lowercaseCharacters: String.CharacterView
    private(set) var currentIndex: String.CharacterView.Index
    
    init(string: String) {
        characters = string.characters

        currentIndex = currentIndex.advancedBy(delta)
    }
    
    subscript (i: String.Index) -> Character {
        return characters[i]
    }
    
    subscript (r: Range<String.Index>) -> String {
        return String(characters[r])
    }
}
