code: int mapPosition(int position) {
  		int out = position;
  		for (int delta : positionDeltas.headMap(position, true).values()) {
  			out += delta;
  		}
  		return out;
  	}
docs: Maps a position in the {@code preprocessed} string to the equivalent character in the {@code rawInput}.
  
  The difference is caused by decoding backslash-U unicode escapes, for example.