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javaguava

Merge ranges with guava

I need to merge some ranges.

I discovered guava and see that it can handle it in some cases.

RangeSet<Integer> rangeSet = TreeRangeSet.create();
rangeSet.add(Range.closed(1, 10)); // {[1, 10]}
rangeSet.add(Range.closed(8, 15)); // {[1, 15]}

Now, I need to tell Guava that I need that [1, 10] + [11, 20] = {[1, 20]} and not {[1, 10], [11, 20]}.

Is there an option somewhere for this?

Solution

  • If you want ranges like this to be merged, you need to canonicalize them first:

    rangeSet.add(Range.closed(1, 10).canonical(DiscreteDomain.integers()); 
// {[1, 11)}
rangeSet.add(Range.closed(11, 20).canonical(DiscreteDomain.integers());
// {[1, 21)}