// copy on write so we can cache a..a intervals and sets of that protected internal virtual void Add(Interval addition) { if (@readonly) { throw new InvalidOperationException("can't alter readonly IntervalSet"); } //System.out.println("add "+addition+" to "+intervals.toString()); if (addition.b < addition.a) { return; } // find position in list // Use iterators as we modify list in place for (int i = 0; i < intervals.Count; i++) { Interval r = intervals[i]; if (addition.Equals(r)) { return; } if (addition.Adjacent(r) || !addition.Disjoint(r)) { // next to each other, make a single larger interval Interval bigger = addition.Union(r); intervals[i] = bigger; // make sure we didn't just create an interval that // should be merged with next interval in list while (i < intervals.Count - 1) { i++; Interval next = intervals[i]; if (!bigger.Adjacent(next) && bigger.Disjoint(next)) { break; } // if we bump up against or overlap next, merge intervals.RemoveAt(i); // remove this one i--; // move backwards to what we just set intervals[i] = bigger.Union(next); // set to 3 merged ones } // first call to next after previous duplicates the result return; } if (addition.StartsBeforeDisjoint(r)) { // insert before r intervals.Insert(i, addition); return; } } // if disjoint and after r, a future iteration will handle it // ok, must be after last interval (and disjoint from last interval) // just add it intervals.Add(addition); }