/// <summary>
/// Adds a new value at this node.
/// </summary>
/// <param name="idx"></param>
/// <param name="key"></param>
/// <param name="value"></param>
/// <returns></returns>
internal void Add(short idx, string key, T value)
{
// TODO: improve on this by inserting the mean value first.
// TODO: improve on this by remove recursion and going to iteration.
char s = key[idx];
if (s < _split_char)
{ // s belongs at the low side.
// recursively add to the low side.
if (_lower_node == null)
{ // there is no lower node; create one.
_lower_node = new StringTreeNode(key[idx]);
_lower_node.Add(idx, key, value);
}
else
{ // add to the lower node.
_lower_node.Add(idx, key, value);
}
}
else if (s == _split_char)
{ // s belongs at the equal node.
if (idx < key.Length - 1)
{ // there are still other chars left!
if (_equal_node == null)
{ // there is no equal node; create one.
_equal_node = new StringTreeNode(key[idx + 1]);
}
// add to the equals node.
_equal_node.Add((short)(idx + 1), key, value);
}
else
{ // there are no other char's left! assign the value here!
_value = value; // no recursion anymore, it ends here!
}
}
else
{ // s belongs at the high side.
// recursively add to the high side.
if (_higher_node == null)
{ // there is no higher node; create one.
_higher_node = new StringTreeNode(key[idx]);
_higher_node.Add(idx, key, value);
}
else
{ // add to the lower node.
_higher_node.Add(idx, key, value);
}
}
}
public void AddShouldCreateAChildNodeForTheFirstLetterIfItDoesNotExist()
{
node.Add("a");
Assert.IsType <StringTreeNode>(node.Find("a"));
}