private static Func <string, string, string, bool> GetRangePredicateFunction(this RangeInclude src)
{
switch (src)
{
case RangeInclude.Both:
return(Utils.RangeBetweenIncludingBoth);
case RangeInclude.Neither:
return(Utils.RangeBetweenExcludingBoth);
case RangeInclude.Lower:
return(Utils.RangeBetweenIncludingLower);
case RangeInclude.Higher:
return(Utils.RangeBetweenIncludingHigher);
}
throw new Exception("Unknown Range Include: " + src);
}
public static IEnumerable <KeyValuePair <string, TValue> > GetRange <TValue>(this SortedList <string, TValue> src, string keyFrom, string keyTo, RangeInclude rangeInclude)
{
var rangeIncludeFunc = rangeInclude.GetRangePredicateFunction();
if (string.CompareOrdinal(keyFrom, keyTo) > 0)
{
return(Array.Empty <KeyValuePair <string, TValue> >());
}
if (src.Count < MinAmountToScan)
{
return(src.Where(itm => rangeIncludeFunc(itm.Key, keyFrom, keyTo)));
}
var fromIndex = src.FindNearest(keyFrom);
var toIndex = src.FindNearest(keyTo);
var result = new List <KeyValuePair <string, TValue> >();
for (var i = fromIndex; i <= toIndex; i++)
{
if (rangeIncludeFunc(src.Keys[i], keyFrom, keyTo))
{
result.Add(new KeyValuePair <string, TValue>(src.Keys[i], src.Values[i]));
}
}
return(result);
}
