// an array of 6-byte integers
persistable sclass HalfLongs {
  short[] data;
  int length;
  
  *(int *length) {
    data = new short[safeToInt(length*3L)];
  }

  public int size() { ret length; }
  
  public void set(int i, long val) {
    data[i*3] = (short) val;
    data[i*3+1] = (short) (val >> 16);
    data[i*3+2] = (short) (val >> 32);
  }
  
  public long get(int i) {
    ret ushortToLong(data[i*3])
      | (ushortToLong(data[i*3+1]) << 16)
      | (data[i*3+2] << 32);
  }
}