public static IEnumerable <PercentileWeight> CoveringRange(this IEnumerable <PercentileWeight> inputs, PercentileWeight coveringRange)
{
//todo: following code expects no overlaps check that none exist
//create lower and upper weights from coveringRange
var lower = new PercentileWeight(decimal.MinValue, true, coveringRange.LowerBoundPercentageRanking, !coveringRange.LowerBoundInclusive);
var upper = new PercentileWeight(coveringRange.UpperBoundPercentageRanking, !coveringRange.UpperBoundInclusive, decimal.MaxValue, true);
//union new lower and upper weights with incoming list and order to process
var orderedInputs = inputs.Union(new [] { lower, upper })
.OrderBy(item => item.LowerBoundPercentageRanking)
.ToList();
//process list in order filling in the gaps
for (var i = 1; i < orderedInputs.Count; i++)
{
var gap = GetPercentileWeightBetweenLowerAndUpper(orderedInputs[i - 1], orderedInputs[i]);
if (gap != null)
{
yield return(gap);
}
//dont want to output last input this represents the fake upper made above and wasnt in the original input
if (i < (orderedInputs.Count - 1))
{
yield return(orderedInputs[i]);
}
}
}
private static PercentileWeight GetPercentileWeightBetweenLowerAndUpper(PercentileWeight lowerWeight, PercentileWeight upperWeight)
{
var lower = lowerWeight.UpperBoundPercentageRanking;
var lowerInclusive = lowerWeight.UpperBoundInclusive;
var upper = upperWeight.LowerBoundPercentageRanking;
var upperInclusive = upperWeight.LowerBoundInclusive;
//see if there is a gap between lower and upper (offset by a small delta for non inclusive ranges)
var diff = (upper + (upperInclusive ? 0 : Delta)) - (lower - (lowerInclusive ? 0 : Delta));
if (diff > Delta)
{
//there was a gap so return a new weight to fill it
return(new PercentileWeight
{
LowerBoundPercentageRanking = lower,
LowerBoundInclusive = !lowerInclusive,
UpperBoundPercentageRanking = upper,
UpperBoundInclusive = !upperInclusive
});
}
return(null);
}
