final sclass DoubleRange implements Comparable<DoubleRange> {
  gettable double start;
  gettable double end;
  
  *() {}
  *(double *start, double *end) {}
  
  [stdEq]
  
  double length() { ret end-start; }
  bool isEmpty() { ret start >= end; }
  double center() { ret (start+end)/2; }
  
  sS _fieldOrder = "start end";
  
  toString { ret "[" + start + ";" + end + "]"; }
  
  @Override public int compareTo(DoubleRange r) {
    int c = cmp(start, r.start);
    if (c != 0) ret c;
    ret cmp(end, r.end);
  }
  
  bool contains(double d) {
    ret d >= start && d <= end;
  }
  
  DoubleRange sort() {
    ret start > end ? doubleRange(end, start) : this;
  }
}

Began life as a copy of #1008631