anchor.diff:         return med;
        }
      }
  -   return ~min;
  +   // [min] is the insertion position in the range [0, max].
  +   // Return a negative value in the range [-max - 1, -1].
  +   return -(min + 1);
     }
   
     /**
  
positive.code: 
    /**
     * Returns the position of [item] in [items] if present.
     * Returns the bitwise complement (~) of the insertion position if [item] is
     * not found.
     */
    static int _binarySearch(List items, var item) {
     int min = 0;
  
negative.code: 
      int lineIndex = _binarySearch(_lineOffsets, position);
      if (lineIndex < 0) {
        // Note: we need "- 2" because 1) we adjust for the "+1" of the return
        // value of the search (insertion position), and 2) we are interested
        // in the line containing [position], not the insertion position of
        // [position] in the array.
        lineIndex = -lineIndex - 2;
      }
      assert(lineIndex >= 0 && lineIndex < _lineOffsets.length);
      return lineIndex;
  