// to give. The return values are the number of bytes to advance the input
// and the next token to return to the user, plus an error, if any. If the
// data does not yet hold a complete token, for instance if it has no newline
-// while scanning lines, SplitFunc can return (0, nil) to signal the Scanner
-// to read more data into the slice and try again with a longer slice
+// while scanning lines, SplitFunc can return (0, nil, nil) to signal the
+// Scanner to read more data into the slice and try again with a longer slice
// starting at the same point in the input.
//
// If the returned error is non-nil, scanning stops and the error