function indexShiftJISPointerFor(code_point) {
    // 1. Let index be index jis0208 excluding all entries whose
    // pointer is in the range 8272 to 8835, inclusive.
    shift_jis_index = shift_jis_index ||
      index('jis0208').map(function(code_point, pointer) {
        return inRange(pointer, 8272, 8835) ? null : code_point;
      });
    var index_ = shift_jis_index;

    // 2. Return the index pointer for code point in index.
    return index_.indexOf(code_point);
  }
@param {number} code_point The |code_point| to search for in the Shift_JIS
    index.
@return {?number} The code point corresponding to |pointer| in |index|,
    or null if |code point| is not in the Shift_JIS index.