 public enum DiffStep<T> : CustomDebugStringConvertible {
     case Insert(Int, T)
     case Delete(Int, T)
-    var isInsertion: Bool {
+    public var isInsertion: Bool {
         switch(self) {
         case .Insert:
             return true

            return "-\(j)@\(i)"
        }
    }
    var idx: Int {
        switch(self) {
        case .Insert(let i, _):
            return i

    }
}

public func +<T> (left: Diff<T>, right: DiffStep<T>) -> Diff<T> {
    return Diff<T>(results: left.results + [right])
}

