public ImmutableDictionaryListPair <TKey, TValue> Insert(int index, KeyValuePair <TKey, TValue> pair)
{
if (index == Count)
{
return(Add(pair));
}
else if (index > Count || index < 0)
{
throw new ArgumentOutOfRangeException(nameof(index), index, $"Needs to be greated than -1 and less than the count of {Count}");
}
// Need to find the node position numbers either side, take the average, and that is the new sort key
BigRationalOld insertSortKey = index > 0 ?
(List[index - 1].SortKey + List[index].SortKey) / (BigRationalOld)2 :
List[index].SortKey - BigRationalOld.One;
// Create the list of nodes for the internal list
var node = new ObservableDictionaryNode <TKey, TValue>(pair, insertSortKey);
// Double update the lists inserting the new node and replacing the after node with a modified version
var newList = List.Insert(index, node);
var newDictionary = Dictionary.Add(node.Key, node);
// Create the new collection
return(new ImmutableDictionaryListPair <TKey, TValue>(newDictionary, newList));
}
public void TestIteratingOnInsertionIndexUpDirectionAlternate1()
{
// If iterations is set to 10_000 it takes 23 minutes to run this test
List <BigRationalOld> testSetLower = new List <BigRationalOld>(_count);
List <BigRationalOld> testSetUpper = new List <BigRationalOld>(_count);
for (int i = 0; i < _count; ++i)
{
testSetLower.Add(i - _count / 2);
testSetUpper.Add(i + 1 - _count / 2);
}
for (int iteration = 0; iteration < _iterations; ++iteration)
{
for (int i = 0; i < _count; ++i)
{
// Get pairs of number, take half way between them, and check it
// is less than the high end and greater than the lower end
BigRationalOld newValue = (testSetLower[i] + testSetUpper[i]) / 2;
Assert.IsTrue(newValue > testSetLower[i]);
Assert.IsTrue(newValue < testSetUpper[i]);
testSetLower[i] = newValue;
}
}
}
public ObservableDictionaryNode(KeyValuePair <TKey, TValue> pair, BigRationalOld position)
{
KeyValuePair = pair;
SortKey = position;
}