/// <summary>
///
/// </summary>
/// <param name="p"></param>
/// <param name="key"></param>
/// <param name="index"></param>
/// <param name="dist"></param>
/// <param name="matches"></param>
internal void NearNeighborsSearch(
TstDictionaryEntry p,
string key,
int index,
int dist,
IList matches
)
{
if (p == null || dist < 0)
{
return;
}
char c = key[index];
// low child
if (dist > 0 || c < p.SplitChar)
{
NearNeighborsSearch(p.LowChild, key, index, dist, matches);
}
// eq child
if (p.IsKey)
{
if (key.Length - index <= dist)
{
matches.Add(new DictionaryEntry(p.Key, p.Value));
}
}
else
{
int localIndex = index;
if (localIndex != key.Length - 1)
{
++localIndex;
}
int localDist = dist;
if (c != p.SplitChar)
{
--localDist;
}
NearNeighborsSearch(
p.EqChild,
key,
localIndex,
localDist,
matches
);
}
// highchild
if (dist > 0 || c > p.SplitChar)
{
NearNeighborsSearch(p.HighChild, key, index, dist, matches);
}
}
/// <summary>
/// Create a dictionary with a specified root.
/// </summary>
/// <param name="root">Root of the new dictionary</param>
protected TstDictionary(TstDictionaryEntry root)
{
if (root == null)
{
throw new ArgumentNullException("root is null");
}
this.root = root;
this.version = 0;
}
/// <summary>
/// Raises the <see cref="TstTraverser.TreeEntry"/> event.
/// </summary>
/// <param name="p">tst node added to the tree</param>
protected virtual void OnTreeEntry(TstDictionaryEntry p)
{
if (TreeEntry != null)
{
TreeEntry(this,
new TstDictionaryEntryEventArgs(p)
);
}
}
/// <summary>
/// Raises the <see cref="TstTraverser.HighChild"/> event.
/// </summary>
/// <param name="p">high child about to be added to the tree</param>
protected virtual void OnLowChild(TstDictionaryEntry p)
{
if (LowChild != null)
{
LowChild(this,
new TstDictionaryEntryEventArgs(p)
);
}
}
/// <summary>
/// Determines whether the <see cref="TstDictionary"/> contains a specific key.
/// </summary>
/// <param name="key">The key to locate in the <see cref="TstDictionary"/>.</param>
/// <returns>true if the <see cref="TstDictionary"/> contains an element with the specified key; otherwise, false.</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="key"/> is a null reference (Nothing in Visual Basic).
/// </exception>
/// <remarks>
/// <para>Complexity: Uses a Ternary Search Tree (tst) to find the key.</para>
/// <para>The method behaves exactly as <see cref="TstDictionary.Contains"/>.</para>
/// </remarks>
public virtual bool ContainsKey(String key)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
TstDictionaryEntry de = Find(key);
return(de != null && de.IsKey);
}
/// <summary>
/// Removes all elements from the <see cref="TstDictionary"/>.
/// </summary>
/// <exception cref="NotSupportedException">The <see cref="TstDictionary"/> is read-only.</exception>
public virtual void Clear()
{
if (IsReadOnly)
{
throw new NotSupportedException("dictionary is read-only");
}
// updating version
++version;
root = null;
}
/// <summary>Constructs an enumerator over <paramref name="tst"/></summary>
/// <param name="tst">dictionary to enumerate.</param>
/// <exception cref="ArgumentNullException">tst is null</exception>
public TstDictionaryEnumerator(TstDictionary tst)
{
if (tst == null)
{
throw new ArgumentNullException("tst");
}
this.version = tst.Version;
this.dictionary = tst;
this.currentNode = null;
this.stack = null;
}
///<summary>
/// Removes the element with the specified key from the <see cref="TstDictionary"/>.
/// </summary>
/// <param name="key">The key of the element to remove.</param>
/// <exception cref="ArgumentNullException">
/// <paramref name="key"/> is a null reference (Nothing in Visual Basic).
/// </exception>
/// <exception cref="ArgumentException"><paramref name="key"/> is an empty string</exception>
/// <exception cref="NotSupportedException">The <see cref="TstDictionary"/> is read-only.</exception>
/// <exception cref="NotSupportedException">The <see cref="TstDictionary"/> has a fixed size.</exception>
public virtual void Remove(String key)
{
if (key == null)
{
throw new ArgumentNullException("key is null");
}
if (key.Length == 0)
{
throw new ArgumentException("key length cannot be 0");
}
if (IsReadOnly)
{
throw new NotSupportedException("dictionary is read-only");
}
if (IsFixedSize)
{
throw new NotSupportedException("dictionary has fixed size");
}
// updating version
++version;
TstDictionaryEntry p = Find(key);
if (p == null)
{
return;
}
p.IsKey = false;
p.Key = null;
while (!p.IsKey && !p.HasChildren && p.Parent != null)
{
if (p.IsLowChild)
{
p.Parent.LowChild = null;
}
else if (p.IsHighChild)
{
p.Parent.HighChild = null;
}
else
{
p.Parent.EqChild = null;
}
p = p.Parent;
}
if (!p.IsKey && !p.HasChildren && p == root)
{
root = null;
}
}
/// <summary>
/// Construct a tst node.
/// </summary>
/// <param name="parent">parent node</param>
/// <param name="splitChar">split character</param>
public TstDictionaryEntry(
TstDictionaryEntry parent,
char splitChar
)
{
this.isKey = false;
this.key = null;
this.value = null;
this.parent = parent;
this.splitChar = splitChar;
this.lowChild = null;
this.eqChild = null;
this.highChild = null;
}
/// <summary>
/// Gets or sets the value associated with the specified key.
/// </summary>
/// <remarks>
/// [C#] In C#, this property is the indexer for the <see cref="TstDictionary"/> class.
/// </remarks>
/// <param name="key">The key whose value to get or set.</param>
/// <value>
/// The value associated with the specified key.
/// If the specified key is not found, attempting to get it returns a null reference
/// (Nothing in Visual Basic), and attempting to set it creates a new element using the specified key.
/// </value>
/// <exception cref="ArgumentNullException"><paramref name="key"/> is a null reference</exception>
/// <exception cref="ArgumentException">
/// The property is set and <paramref name="key"/> is an empty string
/// </exception>
/// <exception cref="NotSupportedException">
/// The property is set and the <see cref="TstDictionary"/> is read-only.
/// </exception>
/// <exception cref="NotSupportedException">
/// The property is set, <paramref name="key"/> does not exist in the collection,
/// and the <see cref="TstDictionary"/> has a fixed size.
/// </exception>
public virtual Object this[String key]
{
get
{
if (key == null)
{
throw new ArgumentNullException("key");
}
TstDictionaryEntry de = Find(key);
if (de == null)
{
return(null);
}
else
{
return(de.Value);
}
}
set
{
if (key == null)
{
throw new ArgumentNullException("key");
}
if (key.Length == 0)
{
throw new ArgumentException("key is an empty string");
}
if (IsReadOnly)
{
throw new NotSupportedException("read-only dictionary");
}
// updating version
++version;
TstDictionaryEntry de = Find(key);
if (de == null)
{
Add(key, value);
}
else
{
if (IsFixedSize)
{
throw new NotSupportedException("fixed-size dictionary");
}
de.Value = value;
}
}
}
/// <summary>
/// Advances the enumerator to the next element of the collection.
/// </summary>
/// <returns>
/// true if the enumerator was successfully advanced to the next element;
/// false if the enumerator has passed the end of the collection.
/// </returns>
public bool MoveNext()
{
this.ThrowIfChanged();
// we are at the beginning
if (stack == null)
{
stack = new Stack();
currentNode = null;
if (dictionary.Root != null)
{
stack.Push(dictionary.Root);
}
}
// we are at the end node, finished
else if (currentNode == null)
{
throw new InvalidOperationException("out of range");
}
if (stack.Count == 0)
{
currentNode = null;
}
while (stack.Count > 0)
{
currentNode = (TstDictionaryEntry)stack.Pop();
if (currentNode.HighChild != null)
{
stack.Push(currentNode.HighChild);
}
if (currentNode.EqChild != null)
{
stack.Push(currentNode.EqChild);
}
if (currentNode.LowChild != null)
{
stack.Push(currentNode.LowChild);
}
if (currentNode.IsKey)
{
break;
}
}
return(currentNode != null);
}
/// <summary>
/// Traverses the <paramref name="p"/> sub-tree.
/// </summary>
/// <param name="p">node to traverse.</param>
protected void Traverse(TstDictionaryEntry p)
{
if (p == null)
{
return;
}
OnTreeEntry(p);
OnLowChild(p.LowChild);
Traverse(p.LowChild);
OnEqChild(p.EqChild);
Traverse(p.EqChild);
OnHighChild(p.HighChild);
Traverse(p.HighChild);
}
/// <summary>
/// Creates a shallow copy of the entry
/// </summary>
/// <returns>entry shallow copy</returns>
public Object Clone()
{
TstDictionaryEntry entry = new TstDictionaryEntry(Parent, SplitChar);
if (LowChild != null)
{
entry.LowChild = LowChild.Clone() as TstDictionaryEntry;
}
if (EqChild != null)
{
entry.EqChild = EqChild.Clone() as TstDictionaryEntry;
}
if (HighChild != null)
{
entry.HighChild = HighChild.Clone() as TstDictionaryEntry;
}
return(entry);
}
/// <summary>
/// Finds the tst node matching the key.
/// </summary>
/// <returns>the <see cref="TstDictionaryEntry"/> mathcing the key, null if not found.</returns>
/// <exception cref="ArgumentNullException"><paramref name="key"/> is null.</exception>
public virtual TstDictionaryEntry Find(String key)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
int n = key.Length;
if (n == 0)
{
return(null);
}
TstDictionaryEntry p = Root;
int index = 0;
char c;
while (index < n && p != null)
{
c = key[index];
if (c < p.SplitChar)
{
p = p.LowChild;
}
else if (c > p.SplitChar)
{
p = p.HighChild;
}
else
{
if (index == n - 1)
{
return(p);
}
else
{
++index;
p = p.EqChild;
}
}
}
return(p);
}
/// <summary>
///
/// </summary>
/// <param name="p"></param>
/// <param name="key"></param>
/// <param name="index"></param>
/// <param name="wildChar"></param>
/// <param name="matches"></param>
internal void PartialMatchSearch(
TstDictionaryEntry p,
string key,
int index,
char wildChar,
IList matches
)
{
if (p == null)
{
return;
}
char c = key[index];
if (c == wildChar || c < p.SplitChar)
{
PartialMatchSearch(p.LowChild, key, index, wildChar, matches);
}
if (c == wildChar || c == p.SplitChar)
{
if (index < key.Length - 1)
{
PartialMatchSearch(p.EqChild, key, index + 1, wildChar, matches);
}
else if (p.IsKey)
{
matches.Add(new DictionaryEntry(p.Key, p.Value));
}
}
if (c == wildChar || c > p.SplitChar)
{
PartialMatchSearch(p.HighChild, key, index, wildChar, matches);
}
}
///<summary>
/// Adds an element with the specified key and value into the <see cref="TstDictionary"/>.
///</summary>
/// <param name="key">The key of the element to add.</param>
/// <param name="value">The value of the element to add. The value can be a null reference (Nothing in Visual Basic).</param>
/// <exception cref="ArgumentNullException">
/// <paramref name="key"/> is a null reference (Nothing in Visual Basic).
/// </exception>
/// <exception cref="ArgumentException"><paramref name="key"/> is an empty string</exception>
/// <exception cref="ArgumentException">
/// An element with the same key already exists in the <see cref="TstDictionary"/>.
/// </exception>
/// <exception cref="NotSupportedException">The <see cref="TstDictionary"/> is read-only.</exception>
/// <exception cref="NotSupportedException">The <see cref="TstDictionary"/> has a fixed size.</exception>
public virtual void Add(String key, Object value)
{
if (key == null)
{
throw new ArgumentNullException("key is null");
}
if (key.Length == 0)
{
throw new ArgumentException("trying to add empty key");
}
if (IsReadOnly)
{
throw new NotSupportedException("dictionary is read-only");
}
if (IsFixedSize)
{
throw new NotSupportedException("dictionary has fixed size");
}
// updating version
++version;
// creating root node if needed.
if (Root == null)
{
root = new TstDictionaryEntry(null, key[0]);
}
// adding key
TstDictionaryEntry p = Root;
int i = 0;
char c;
while (i < key.Length)
{
c = key[i];
if (c < p.SplitChar)
{
if (p.LowChild == null)
{
p.LowChild = new TstDictionaryEntry(p, c);
}
p = p.LowChild;
continue;
}
if (c > p.SplitChar)
{
if (p.HighChild == null)
{
p.HighChild = new TstDictionaryEntry(p, c);
}
p = p.HighChild;
continue;
}
else
{
++i;
if (i == key.Length)
{
if (p.IsKey)
{
throw new ArgumentException("key already in dictionary");
}
break;
}
if (p.EqChild == null)
{
p.EqChild = new TstDictionaryEntry(p, key[i]);
}
p = p.EqChild;
}
}
p.IsKey = true;
p.Key = key;
p.Value = value;
}
/// <summary>Create a <see cref="TstDictionaryEntry"/> event argument.</summary>
/// <param name="entry">A <see cref="TstDictionaryEntry"/> entry to pass as argument.</param>
public TstDictionaryEntryEventArgs(TstDictionaryEntry entry)
{
this.entry = entry;
}
///<summary>
/// Constructor
///</summary>
/// <remarks>
/// Construct an empty ternary search tree.
/// </remarks>
public TstDictionary()
{
root = null;
version = 0;
}
