Stepping Through Segments

I am using this code to try to inspect segments of a score:

  onRun: {
     var cursor = curScore.newCursor();
     cursor.rewind(0);
     while(cursor.segment) {
        console.log(cursor.segment.segmentType);
        cursor.next();
     }
     Qt.quit()
  }

}

But it tells me that every segment is of type ChordRest.

Why am I missing all the other segment types, like TimeSig, Clef, etc. ?