/// <summary>
/// Gets the node value associated with the specified path.
/// </summary>
/// <param name="enumerable">An enumerable object that specifies the path of the node to get.</param>
/// <param name="value">When this method returns, contains the node value associated with the specified path, if the key is found; otherwise, the default value for the type of the value parameter. This parameter is passed uninitialized.</param>
/// <returns>True if the tree contains the specified node; otherwise, false.</returns>
public bool TryGetValue(IEnumerable <TKey> enumerable, out TValue value)
{
PrefixTreeNode <TKey, TValue> currentNode = this.GetMatchedNode(enumerable);
bool hasValue = currentNode != null && currentNode.HasValue;
value = hasValue ? currentNode.Value : default(TValue);
return(hasValue);
}
/// <summary>
/// Sets the node value associated with the specified path if that node doesn't exist.
/// </summary>
/// <param name="enumerable">An enumerable object that specifies the path of the node to set.</param>
/// <param name="value">The value of the node to set.</param>
/// <returns>True if the set operation is success; otherwise, false. This method returns false if the specified node is already existed in the tree.</returns>
public bool TrySetValue(IEnumerable <TKey> enumerable, TValue value)
{
PrefixTreeNode <TKey, TValue> currentNode = this.GetMatchedNode(enumerable, true);
if (currentNode.HasValue)
{
return(false);
}
currentNode.Value = value;
return(true);
}
private PrefixTreeNode <TKey, TValue> GetMatchedNode(IEnumerable <TKey> enumerable, bool createNew)
{
PrefixTreeNode <TKey, TValue> currentNode = null;
foreach (KeyValuePair <TKey, PrefixTreeNodeCollection <TKey, TValue> > pair
in this.PrefixNodePath(enumerable))
{
if (!pair.Value.ContainsKey(pair.Key))
{
if (!createNew)
{
return(null);
}
pair.Value[pair.Key] = new PrefixTreeNode <TKey, TValue>();
}
currentNode = pair.Value[pair.Key];
}
return(currentNode);
}
/// <summary>
/// Applies the longest prefix match algorithm to the given enumerable object.
/// </summary>
/// <param name="enumerable">An enumerable to find a longest matching in the prefix tree.</param>
/// <returns>A <see cref="PrefixMatch<TKey, TValue>"/> that represents the result of the longest prefix matching.</returns>
public PrefixMatch <TKey, TValue> LongestPrefixMatch(IEnumerable <TKey> enumerable)
{
PrefixTreeNode <TKey, TValue> longestNode = null;
int currentLength = 1, longestLength = 0;
foreach (KeyValuePair <TKey, PrefixTreeNodeCollection <TKey, TValue> > pair
in this.PrefixNodePath(enumerable))
{
if (!pair.Value.ContainsKey(pair.Key))
{
break;
}
if (pair.Value[pair.Key].HasValue)
{
longestNode = pair.Value[pair.Key];
longestLength = currentLength;
}
currentLength++;
}
return(new PrefixMatch <TKey, TValue>(longestNode, longestLength));
}
/// <summary>
/// Determines whether the tree contains the specified node.
/// </summary>
/// <param name="enumerable">An enumerable object that specifies the path of the node.</param>
/// <returns>True if the tree contains the specified node; otherwise, false.</returns>
public bool HasValue(IEnumerable <TKey> enumerable)
{
PrefixTreeNode <TKey, TValue> currentNode = this.GetMatchedNode(enumerable);
return(currentNode != null && currentNode.HasValue);
}
public override bool TryGetValue(TKey key, out PrefixTreeNode <TKey, TValue> value)
{
return(this.collection.TryGetValue(key, out value));
}
public override void Add(TKey key, PrefixTreeNode <TKey, TValue> value)
{
this.collection.Add(key, value);
}
internal PrefixMatch(PrefixTreeNode <TKey, TValue> node, int length)
{
this.node = node;
this.length = length;
}
/// <summary>
/// Sets the node value associated with the specified path.
/// </summary>
/// <param name="enumerable">An enumerable object that specifies the path of the node to set.</param>
/// <param name="value">The value of the node to set.</param>
public void SetValue(IEnumerable <TKey> enumerable, TValue value)
{
PrefixTreeNode <TKey, TValue> currentNode = this.GetMatchedNode(enumerable, true);
currentNode.Value = value;
}
/// <summary>
/// Gets the node value associated with the specified path.
/// </summary>
/// <param name="enumerable">An enumerable object that specifies the path of the node to get.</param>
/// <returns>The node value associated with the specified path</returns>
public TValue GetValue(IEnumerable <TKey> enumerable)
{
PrefixTreeNode <TKey, TValue> currentNode = this.GetMatchedNode(enumerable);
return(currentNode.Value);
}