public ListSegment <TSpan> GetSpans(int startPosition, int length)
{
var segmentList = new SegmentRangeList(Segments);
var segmentListRange = segmentList.GetReadOnlyList().GetRange(new Range(startPosition, length),
(searchRange, segmentRange) => RangeHelper.MinCompare(searchRange, segmentRange, inclusive: true),
(searchRange, segmentRange) => RangeHelper.MaxCompare(searchRange, segmentRange, inclusive: true));
var segmentStart = segmentListRange.Start;
var segmentCount = segmentListRange.Count;
var absoluteStart = segmentStart << SegmentSpanCountBitWidth;
var absoluteLength = segmentCount << SegmentSpanCountBitWidth;
var endSegmentExclusive = segmentStart + segmentCount;
if (endSegmentExclusive >= Segments.Count)
{
absoluteLength -= (SegmentOffsetBitMask - (SegmentOffsetBitMask & (Count - 1)));
}
var spanRangeList = IndexableListAdapter.GetReadOnlyList(new SpanRangeList(this));
var rangeListSegment = new ListSegment <Range>(spanRangeList, absoluteStart, absoluteLength);
var spanRange = rangeListSegment.GetRange(new Range(startPosition, length),
(r, start) => RangeHelper.MinCompare(r, start, inclusive: true),
(r, start) => RangeHelper.MaxCompare(r, start, inclusive: true));
return(new ListSegment <TSpan>(this.GetReadOnlyList(), rangeListSegment.Start + spanRange.Start, spanRange.Count));
}