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2026-07-16 21:49:59 +01:00

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C#

// Copyright (c) 2014 AlphaSierraPapa for the SharpDevelop Team
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.Linq;
using System.Text;
namespace Unity.CodeEditor.Utils
{
/// <summary>
/// A kind of List&lt;T&gt;, but more efficient for random insertions/removal.
/// Also has cheap Clone() and SubRope() implementations.
/// </summary>
/// <remarks>
/// This class is not thread-safe: multiple concurrent write operations or writes concurrent to reads have undefined behaviour.
/// Concurrent reads, however, are safe.
/// However, clones of a rope are safe to use on other threads even though they share data with the original rope.
/// </remarks>
[SuppressMessage("Microsoft.Naming", "CA1710:IdentifiersShouldHaveCorrectSuffix")]
internal sealed class Rope<T> : IList<T>, ICloneable
{
internal RopeNode<T> Root { get; set; }
internal Rope(RopeNode<T> root)
{
Root = root;
root.CheckInvariants();
}
/// <summary>
/// Creates a new rope representing the empty string.
/// </summary>
internal Rope()
{
// we'll construct the empty rope as a clone of an imaginary static empty rope
Root = RopeNode<T>.EmptyRopeNode;
Root.CheckInvariants();
}
/// <summary>
/// Creates a rope from the specified input.
/// This operation runs in O(N).
/// </summary>
/// <exception cref="ArgumentNullException">input is null.</exception>
internal Rope(IEnumerable<T> input)
{
if (input == null)
throw new ArgumentNullException(nameof(input));
if (input is Rope<T> inputRope)
{
// clone ropes instead of copying them
inputRope.Root.Publish();
Root = inputRope.Root;
}
else
{
// ReSharper disable ConditionIsAlwaysTrueOrFalse
// ReSharper disable ExpressionIsAlwaysNull
// ReSharper disable SuspiciousTypeConversion.Global
#pragma warning disable IDE0019 // Use pattern matching
var text = input as string;
#pragma warning restore IDE0019 // Use pattern matching
// ReSharper restore SuspiciousTypeConversion.Global
if (text != null)
// ReSharper restore ConditionIsAlwaysTrueOrFalse
// ReSharper restore ExpressionIsAlwaysNull
// ReSharper disable HeuristicUnreachableCode
{
// if a string is IEnumerable<T>, then T must be char
((Rope<char>)(object)this).Root = CharRope.InitFromString(text);
}
// ReSharper restore HeuristicUnreachableCode
else
{
var arr = ToArray(input);
Root = RopeNode<T>.CreateFromArray(arr, 0, arr.Length);
}
}
Root.CheckInvariants();
}
/// <summary>
/// Creates a rope from a part of the array.
/// This operation runs in O(N).
/// </summary>
/// <exception cref="ArgumentNullException">input is null.</exception>
internal Rope(T[] array, int arrayIndex, int count)
{
VerifyArrayWithRange(array, arrayIndex, count);
Root = RopeNode<T>.CreateFromArray(array, arrayIndex, count);
Root.CheckInvariants();
}
/// <summary>
/// Creates a new rope that lazily initalizes its content.
/// </summary>
/// <param name="length">The length of the rope that will be lazily loaded.</param>
/// <param name="initializer">
/// The callback that provides the content for this rope.
/// <paramref name="initializer"/> will be called exactly once when the content of this rope is first requested.
/// It must return a rope with the specified length.
/// Because the initializer function is not called when a rope is cloned, and such clones may be used on another threads,
/// it is possible for the initializer callback to occur on any thread.
/// </param>
/// <remarks>
/// Any modifications inside the rope will also cause the content to be initialized.
/// However, insertions at the beginning and the end, as well as inserting this rope into another or
/// using the <see cref="Concat(Rope{T},Rope{T})"/> method, allows constructions of larger ropes where parts are
/// lazily loaded.
/// However, even methods like Concat may sometimes cause the initializer function to be called, e.g. when
/// two short ropes are concatenated.
/// </remarks>
[SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures")]
internal Rope(int length, Func<Rope<T>> initializer)
{
if (initializer == null)
throw new ArgumentNullException(nameof(initializer));
if (length < 0)
throw new ArgumentOutOfRangeException(nameof(length), length, "Length must not be negative");
Root = length == 0 ? RopeNode<T>.EmptyRopeNode : new FunctionNode<T>(length, initializer);
Root.CheckInvariants();
}
private static T[] ToArray(IEnumerable<T> input)
{
var arr = input as T[];
return arr ?? input.ToArray();
}
/// <summary>
/// Clones the rope.
/// This operation runs in linear time to the number of rope nodes touched since the last clone was created.
/// If you count the per-node cost to the operation modifying the rope (doing this doesn't increase the complexity of the modification operations);
/// the remainder of Clone() runs in O(1).
/// </summary>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
public Rope<T> Clone()
{
// The Publish() call actually modifies this rope instance; but this modification is thread-safe
// as long as the tree structure doesn't change during the operation.
Root.Publish();
return new Rope<T>(Root);
}
object ICloneable.Clone()
{
return Clone();
}
/// <summary>
/// Resets the rope to an empty list.
/// Runs in O(1).
/// </summary>
public void Clear()
{
Root = RopeNode<T>.EmptyRopeNode;
OnChanged();
}
/// <summary>
/// Gets the length of the rope.
/// Runs in O(1).
/// </summary>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
internal int Length => Root.Length;
/// <summary>
/// Gets the length of the rope.
/// Runs in O(1).
/// </summary>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
public int Count => Root.Length;
/// <summary>
/// Inserts another rope into this rope.
/// Runs in O(lg N + lg M), plus a per-node cost as if <c>newElements.Clone()</c> was called.
/// </summary>
/// <exception cref="ArgumentNullException">newElements is null.</exception>
/// <exception cref="ArgumentOutOfRangeException">index or length is outside the valid range.</exception>
internal void InsertRange(int index, Rope<T> newElements)
{
if (index < 0 || index > Length)
{
throw new ArgumentOutOfRangeException(nameof(index), index, "0 <= index <= " + Length.ToString(CultureInfo.InvariantCulture));
}
if (newElements == null)
throw new ArgumentNullException(nameof(newElements));
newElements.Root.Publish();
Root = Root.Insert(index, newElements.Root);
OnChanged();
}
/// <summary>
/// Inserts new elemetns into this rope.
/// Runs in O(lg N + M), where N is the length of this rope and M is the number of new elements.
/// </summary>
/// <exception cref="ArgumentNullException">newElements is null.</exception>
/// <exception cref="ArgumentOutOfRangeException">index or length is outside the valid range.</exception>
internal void InsertRange(int index, IEnumerable<T> newElements)
{
if (newElements == null)
throw new ArgumentNullException(nameof(newElements));
if (newElements is Rope<T> newElementsRope)
{
InsertRange(index, newElementsRope);
}
else
{
var arr = ToArray(newElements);
InsertRange(index, arr, 0, arr.Length);
}
}
/// <summary>
/// Inserts new elements into this rope.
/// Runs in O(lg N + M), where N is the length of this rope and M is the number of new elements.
/// </summary>
/// <exception cref="ArgumentNullException">newElements is null.</exception>
/// <exception cref="ArgumentOutOfRangeException">index or length is outside the valid range.</exception>
internal void InsertRange(int index, T[] array, int arrayIndex, int count)
{
if (index < 0 || index > Length)
{
throw new ArgumentOutOfRangeException(nameof(index), index, "0 <= index <= " + Length.ToString(CultureInfo.InvariantCulture));
}
VerifyArrayWithRange(array, arrayIndex, count);
if (count > 0)
{
Root = Root.Insert(index, array, arrayIndex, count);
OnChanged();
}
}
/// <summary>
/// Appends multiple elements to the end of this rope.
/// Runs in O(lg N + M), where N is the length of this rope and M is the number of new elements.
/// </summary>
/// <exception cref="ArgumentNullException">newElements is null.</exception>
internal void AddRange(IEnumerable<T> newElements)
{
InsertRange(Length, newElements);
}
/// <summary>
/// Appends another rope to the end of this rope.
/// Runs in O(lg N + lg M), plus a per-node cost as if <c>newElements.Clone()</c> was called.
/// </summary>
/// <exception cref="ArgumentNullException">newElements is null.</exception>
internal void AddRange(Rope<T> newElements)
{
InsertRange(Length, newElements);
}
/// <summary>
/// Appends new elements to the end of this rope.
/// Runs in O(lg N + M), where N is the length of this rope and M is the number of new elements.
/// </summary>
/// <exception cref="ArgumentNullException">array is null.</exception>
internal void AddRange(T[] array, int arrayIndex, int count)
{
InsertRange(Length, array, arrayIndex, count);
}
/// <summary>
/// Removes a range of elements from the rope.
/// Runs in O(lg N).
/// </summary>
/// <exception cref="ArgumentOutOfRangeException">offset or length is outside the valid range.</exception>
internal void RemoveRange(int index, int count)
{
VerifyRange(index, count);
if (count > 0)
{
Root = Root.RemoveRange(index, count);
OnChanged();
}
}
/// <summary>
/// Copies a range of the specified array into the rope, overwriting existing elements.
/// Runs in O(lg N + M).
/// </summary>
internal void SetRange(int index, T[] array, int arrayIndex, int count)
{
VerifyRange(index, count);
VerifyArrayWithRange(array, arrayIndex, count);
if (count > 0)
{
Root = Root.StoreElements(index, array, arrayIndex, count);
OnChanged();
}
}
/// <summary>
/// Creates a new rope and initializes it with a part of this rope.
/// Runs in O(lg N) plus a per-node cost as if <c>this.Clone()</c> was called.
/// </summary>
/// <exception cref="ArgumentOutOfRangeException">offset or length is outside the valid range.</exception>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
internal Rope<T> GetRange(int index, int count)
{
VerifyRange(index, count);
var newRope = Clone();
var endIndex = index + count;
newRope.RemoveRange(endIndex, newRope.Length - endIndex);
newRope.RemoveRange(0, index);
return newRope;
}
/*
#region Equality
/// <summary>
/// Gets whether the two ropes have the same content.
/// Runs in O(N + M).
/// </summary>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
internal bool Equals(Rope other)
{
if (other == null)
return false;
// quick detection for ropes that are clones of each other:
if (other.root == this.root)
return true;
if (other.Length != this.Length)
return false;
using (RopeTextReader a = new RopeTextReader(this, false)) {
using (RopeTextReader b = new RopeTextReader(other, false)) {
int charA, charB;
do {
charA = a.Read();
charB = b.Read();
if (charA != charB)
return false;
} while (charA != -1);
return true;
}
}
}
/// <summary>
/// Gets whether two ropes have the same content.
/// Runs in O(N + M).
/// </summary>
public override bool Equals(object obj)
{
return Equals(obj as Rope);
}
/// <summary>
/// Calculates the hash code of the rope's content.
/// Runs in O(N).
/// </summary>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
public override int GetHashCode()
{
int hashcode = 0;
using (RopeTextReader reader = new RopeTextReader(this, false)) {
unchecked {
int val;
while ((val = reader.Read()) != -1) {
hashcode = hashcode * 31 + val;
}
}
}
return hashcode;
}
#endregion
*/
/// <summary>
/// Concatenates two ropes. The input ropes are not modified.
/// Runs in O(lg N + lg M).
/// </summary>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
[SuppressMessage("Microsoft.Design", "CA1000:DoNotDeclareStaticMembersOnGenericTypes")]
internal static Rope<T> Concat(Rope<T> left, Rope<T> right)
{
if (left == null)
throw new ArgumentNullException(nameof(left));
if (right == null)
throw new ArgumentNullException(nameof(right));
left.Root.Publish();
right.Root.Publish();
return new Rope<T>(RopeNode<T>.Concat(left.Root, right.Root));
}
/// <summary>
/// Concatenates multiple ropes. The input ropes are not modified.
/// </summary>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
[SuppressMessage("Microsoft.Design", "CA1000:DoNotDeclareStaticMembersOnGenericTypes")]
internal static Rope<T> Concat(params Rope<T>[] ropes)
{
if (ropes == null)
throw new ArgumentNullException(nameof(ropes));
var result = new Rope<T>();
foreach (var r in ropes)
result.AddRange(r);
return result;
}
#region Caches / Changed event
internal struct RopeCacheEntry
{
internal RopeNode<T> Node { get; }
internal int NodeStartIndex { get; }
internal RopeCacheEntry(RopeNode<T> node, int nodeStartOffset)
{
Node = node;
NodeStartIndex = nodeStartOffset;
}
internal bool IsInside(int offset)
{
return offset >= NodeStartIndex && offset < NodeStartIndex + Node.Length;
}
}
// cached pointer to 'last used node', used to speed up accesses by index that are close together
private volatile ImmutableStack<RopeCacheEntry> _lastUsedNodeStack;
internal void OnChanged()
{
_lastUsedNodeStack = null;
Root.CheckInvariants();
}
#endregion
#region GetChar / SetChar
/// <summary>
/// Gets/Sets a single character.
/// Runs in O(lg N) for random access. Sequential read-only access benefits from a special optimization and runs in amortized O(1).
/// </summary>
/// <exception cref="ArgumentOutOfRangeException">Offset is outside the valid range (0 to Length-1).</exception>
/// <remarks>
/// The getter counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
public T this[int index]
{
get
{
// use unsigned integers - this way negative values for index overflow and can be tested for with the same check
if (unchecked((uint)index >= (uint)Length))
{
throw new ArgumentOutOfRangeException(nameof(index), index, "0 <= index < " + Length.ToString(CultureInfo.InvariantCulture));
}
var entry = FindNodeUsingCache(index).PeekOrDefault();
return entry.Node.Contents[index - entry.NodeStartIndex];
}
set
{
if (index < 0 || index >= Length)
{
throw new ArgumentOutOfRangeException(nameof(index), index, "0 <= index < " + Length.ToString(CultureInfo.InvariantCulture));
}
Root = Root.SetElement(index, value);
OnChanged();
/* Here's a try at implementing the setter using the cached node stack (UNTESTED code!).
* However I don't use the code because it's complicated and doesn't integrate correctly with change notifications.
* Instead, I'll use the much easier to understand recursive solution.
* Oh, and it also doesn't work correctly with function nodes.
ImmutableStack<RopeCacheEntry> nodeStack = FindNodeUsingCache(offset);
RopeCacheEntry entry = nodeStack.Peek();
if (!entry.node.isShared) {
entry.node.contents[offset - entry.nodeStartOffset] = value;
// missing: clear the caches except for the node stack cache (e.g. ToString() cache?)
} else {
RopeNode oldNode = entry.node;
RopeNode newNode = oldNode.Clone();
newNode.contents[offset - entry.nodeStartOffset] = value;
for (nodeStack = nodeStack.Pop(); !nodeStack.IsEmpty; nodeStack = nodeStack.Pop()) {
RopeNode parentNode = nodeStack.Peek().node;
RopeNode newParentNode = parentNode.CloneIfShared();
if (newParentNode.left == oldNode) {
newParentNode.left = newNode;
} else {
Debug.Assert(newParentNode.right == oldNode);
newParentNode.right = newNode;
}
if (parentNode == newParentNode) {
// we were able to change the existing node (it was not shared);
// there's no reason to go further upwards
ClearCacheOnModification();
return;
} else {
oldNode = parentNode;
newNode = newParentNode;
}
}
// we reached the root of the rope.
Debug.Assert(root == oldNode);
root = newNode;
ClearCacheOnModification();
}*/
}
}
internal ImmutableStack<RopeCacheEntry> FindNodeUsingCache(int index)
{
Debug.Assert(index >= 0 && index < Length);
// thread safety: fetch stack into local variable
var stack = _lastUsedNodeStack;
var oldStack = stack;
if (stack == null)
{
stack = ImmutableStack<RopeCacheEntry>.Empty.Push(new RopeCacheEntry(Root, 0));
}
while (!stack.PeekOrDefault().IsInside(index))
stack = stack.Pop();
while (true)
{
var entry = stack.PeekOrDefault();
// check if we've reached a leaf or function node
if (entry.Node.Height == 0)
{
if (entry.Node.Contents == null)
{
// this is a function node - go down into its subtree
entry = new RopeCacheEntry(entry.Node.GetContentNode(), entry.NodeStartIndex);
// entry is now guaranteed NOT to be another function node
}
if (entry.Node.Contents != null)
{
// this is a node containing actual content, so we're done
break;
}
}
// go down towards leaves
stack = stack.Push(index - entry.NodeStartIndex >= entry.Node.Left.Length
? new RopeCacheEntry(entry.Node.Right, entry.NodeStartIndex + entry.Node.Left.Length)
: new RopeCacheEntry(entry.Node.Left, entry.NodeStartIndex));
}
// write back stack to volatile cache variable
// (in multithreaded access, it doesn't matter which of the threads wins - it's just a cache)
if (oldStack != stack)
{
// no need to write when we the cache variable didn't change
_lastUsedNodeStack = stack;
}
// this method guarantees that it finds a leaf node
Debug.Assert(stack.Peek().Node.Contents != null);
return stack;
}
#endregion
#region ToString / WriteTo
internal void VerifyRange(int startIndex, int length)
{
if (startIndex < 0 || startIndex > Length)
{
throw new ArgumentOutOfRangeException(nameof(startIndex), startIndex, "0 <= startIndex <= " + Length.ToString(CultureInfo.InvariantCulture));
}
if (length < 0 || startIndex + length > Length)
{
throw new ArgumentOutOfRangeException(nameof(length), length, "0 <= length, startIndex(" + startIndex + ")+length <= " + Length.ToString(CultureInfo.InvariantCulture));
}
}
internal static void VerifyArrayWithRange(T[] array, int arrayIndex, int count)
{
if (array == null)
throw new ArgumentNullException(nameof(array));
if (arrayIndex < 0 || arrayIndex > array.Length)
{
throw new ArgumentOutOfRangeException(nameof(arrayIndex), arrayIndex, "0 <= arrayIndex <= " + array.Length.ToString(CultureInfo.InvariantCulture));
}
if (count < 0 || arrayIndex + count > array.Length)
{
throw new ArgumentOutOfRangeException(nameof(count), count, "0 <= length, arrayIndex(" + arrayIndex + ")+count <= " + array.Length.ToString(CultureInfo.InvariantCulture));
}
}
/// <summary>
/// Creates a string from the rope. Runs in O(N).
/// </summary>
/// <returns>A string consisting of all elements in the rope as comma-separated list in {}.
/// As a special case, Rope&lt;char&gt; will return its contents as string without any additional separators or braces,
/// so it can be used like StringBuilder.ToString().</returns>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
public override string ToString()
{
#pragma warning disable IDE0019 // Use pattern matching
var charRope = this as Rope<char>;
#pragma warning restore IDE0019 // Use pattern matching
if (charRope != null)
{
return charRope.ToString(0, Length);
}
var b = new StringBuilder();
foreach (var element in this)
{
if (b.Length == 0)
b.Append('{');
else
b.Append(", ");
b.Append(element);
}
b.Append('}');
return b.ToString();
}
internal string GetTreeAsString()
{
#if DEBUG
return Root.GetTreeAsString();
#else
return "Not available in release build.";
#endif
}
#endregion
bool ICollection<T>.IsReadOnly => false;
/// <summary>
/// Finds the first occurance of item.
/// Runs in O(N).
/// </summary>
/// <returns>The index of the first occurance of item, or -1 if it cannot be found.</returns>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
public int IndexOf(T item)
{
return IndexOf(item, 0, Length);
}
/// <summary>
/// Gets the index of the first occurrence the specified item.
/// </summary>
/// <param name="item">Item to search for.</param>
/// <param name="startIndex">Start index of the search.</param>
/// <param name="count">Length of the area to search.</param>
/// <returns>The first index where the item was found; or -1 if no occurrence was found.</returns>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
public int IndexOf(T item, int startIndex, int count)
{
VerifyRange(startIndex, count);
while (count > 0)
{
var entry = FindNodeUsingCache(startIndex).PeekOrDefault();
var contents = entry.Node.Contents;
var startWithinNode = startIndex - entry.NodeStartIndex;
var nodeLength = Math.Min(entry.Node.Length, startWithinNode + count);
var r = Array.IndexOf(contents, item, startWithinNode, nodeLength - startWithinNode);
if (r >= 0)
return entry.NodeStartIndex + r;
count -= nodeLength - startWithinNode;
startIndex = entry.NodeStartIndex + nodeLength;
}
return -1;
}
/// <summary>
/// Gets the index of the last occurrence of the specified item in this rope.
/// </summary>
internal int LastIndexOf(T item)
{
return LastIndexOf(item, 0, Length);
}
/// <summary>
/// Gets the index of the last occurrence of the specified item in this rope.
/// </summary>
/// <param name="item">The search item</param>
/// <param name="startIndex">Start index of the area to search.</param>
/// <param name="count">Length of the area to search.</param>
/// <returns>The last index where the item was found; or -1 if no occurrence was found.</returns>
/// <remarks>The search proceeds backwards from (startIndex+count) to startIndex.
/// This is different than the meaning of the parameters on Array.LastIndexOf!</remarks>
internal int LastIndexOf(T item, int startIndex, int count)
{
VerifyRange(startIndex, count);
var comparer = EqualityComparer<T>.Default;
for (var i = startIndex + count - 1; i >= startIndex; i--)
{
if (comparer.Equals(this[i], item))
return i;
}
return -1;
}
/// <summary>
/// Inserts the item at the specified index in the rope.
/// Runs in O(lg N).
/// </summary>
public void Insert(int index, T item)
{
InsertRange(index, new[] { item }, 0, 1);
}
/// <summary>
/// Removes a single item from the rope.
/// Runs in O(lg N).
/// </summary>
public void RemoveAt(int index)
{
RemoveRange(index, 1);
}
/// <summary>
/// Appends the item at the end of the rope.
/// Runs in O(lg N).
/// </summary>
public void Add(T item)
{
InsertRange(Length, new[] { item }, 0, 1);
}
/// <summary>
/// Searches the item in the rope.
/// Runs in O(N).
/// </summary>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
public bool Contains(T item)
{
return IndexOf(item) >= 0;
}
/// <summary>
/// Copies the whole content of the rope into the specified array.
/// Runs in O(N).
/// </summary>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
public void CopyTo(T[] array, int arrayIndex)
{
CopyTo(0, array, arrayIndex, Length);
}
/// <summary>
/// Copies the a part of the rope into the specified array.
/// Runs in O(lg N + M).
/// </summary>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
public void CopyTo(int index, T[] array, int arrayIndex, int count)
{
VerifyRange(index, count);
VerifyArrayWithRange(array, arrayIndex, count);
Root.CopyTo(index, array, arrayIndex, count);
}
/// <summary>
/// Removes the first occurance of an item from the rope.
/// Runs in O(N).
/// </summary>
public bool Remove(T item)
{
var index = IndexOf(item);
if (index >= 0)
{
RemoveAt(index);
return true;
}
return false;
}
/// <summary>
/// Retrieves an enumerator to iterate through the rope.
/// The enumerator will reflect the state of the rope from the GetEnumerator() call, further modifications
/// to the rope will not be visible to the enumerator.
/// </summary>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
public IEnumerator<T> GetEnumerator()
{
Root.Publish();
return Enumerate(Root);
}
/// <summary>
/// Creates an array and copies the contents of the rope into it.
/// Runs in O(N).
/// </summary>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
internal T[] ToArray()
{
var arr = new T[Length];
Root.CopyTo(0, arr, 0, arr.Length);
return arr;
}
/// <summary>
/// Creates an array and copies the contents of the rope into it.
/// Runs in O(N).
/// </summary>
/// <remarks>
/// This method counts as a read access and may be called concurrently to other read accesses.
/// </remarks>
internal T[] ToArray(int startIndex, int count)
{
VerifyRange(startIndex, count);
var arr = new T[count];
CopyTo(startIndex, arr, 0, count);
return arr;
}
private static IEnumerator<T> Enumerate(RopeNode<T> node)
{
var stack = new Stack<RopeNode<T>>();
while (node != null)
{
// go to leftmost node, pushing the right parts that we'll have to visit later
while (node.Contents == null)
{
if (node.Height == 0)
{
// go down into function nodes
node = node.GetContentNode();
continue;
}
Debug.Assert(node.Right != null);
stack.Push(node.Right);
node = node.Left;
}
// yield contents of leaf node
for (var i = 0; i < node.Length; i++)
{
yield return node.Contents[i];
}
// go up to the next node not visited yet
node = stack.Count > 0 ? stack.Pop() : null;
}
}
IEnumerator IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
}
}