public TrieItem(Bits prefix, bool hasValue, T value, TrieItem <T> @true, TrieItem <T> @false)
{
Prefix = prefix;
HasValue = hasValue;
Value = value;
True = @true;
False = @false;
}
private void AddToChild(ref TrieItem <T> child, IEnumerable <bool> enumerable, T value)
{
var bits = new Bits(enumerable);
if (child == null)
{
child = new TrieItem <T>(bits, value);
}
else
{
var commonBits = child.Prefix.Common(bits);
if (child.Prefix.Count == commonBits.Count)
{
if (child.Prefix.Count == bits.Count)
{
// Set value, if not already set
if (child.HasValue)
{
throw new ArgumentException("Duplicate key");
}
var oldChild = child;
child = new TrieItem <T>(oldChild.Prefix, true, value, oldChild.True, oldChild.False);
}
else
{
child.AddItem(bits, value);
}
}
else
{
//split subtrie along the common prefix
var oldChild = child;
if (commonBits.Count == bits.Count)
{
child = new TrieItem <T>(commonBits, value);
}
else
{
child = new TrieItem <T>(commonBits);
child.AddItem(bits, value);
}
child.MakeGrandchild(oldChild);
}
}
}
private void MakeGrandchild(TrieItem <T> oldChild)
{
var discriminator = oldChild.Prefix.Skip(Prefix.Count).First();
var grandchild = new TrieItem <T>(oldChild.Prefix.Skip(Prefix.Count + 1), oldChild.HasValue, oldChild.Value, oldChild.True, oldChild.False);
if (discriminator)
{
if (True != null)
{
throw new InvalidOperationException("Child 1 already set");
}
True = grandchild;
}
else
{
if (False != null)
{
throw new InvalidOperationException("Child 0 already set");
}
False = grandchild;
}
}