/// <summary>
/// Initializes an <see cref="Enumerator"/> structure.
/// </summary>
/// <param name="root">The root of the set to be enumerated.</param>
/// <param name="builder">The builder, if applicable.</param>
/// <param name="startIndex">The index of the first element to enumerate.</param>
/// <param name="count">The number of elements in this collection.</param>
/// <param name="reversed"><c>true</c> if the list should be enumerated in reverse order.</param>
internal Enumerator(Node root, Builder builder = null, int startIndex = -1, int count = -1, bool reversed = false)
{
Requires.NotNull(root, nameof(root));
Requires.Range(startIndex >= -1, nameof(startIndex));
Requires.Range(count >= -1, nameof(count));
Requires.Argument(reversed || count == -1 || (startIndex == -1 ? 0 : startIndex) + count <= root.Count);
Requires.Argument(!reversed || count == -1 || (startIndex == -1 ? root.Count - 1 : startIndex) - count + 1 >= 0);
_root = root;
_builder = builder;
_current = null;
_startIndex = startIndex >= 0 ? startIndex : (reversed ? root.Count - 1 : 0);
_count = count == -1 ? root.Count : count;
_remainingCount = _count;
_reversed = reversed;
_enumeratingBuilderVersion = builder != null ? builder.Version : -1;
_poolUserId = SecureObjectPool.NewId();
_stack = null;
if (_count > 0)
{
if (!s_EnumeratingStacks.TryTake(this, out _stack))
{
_stack = s_EnumeratingStacks.PrepNew(this, new Stack <RefAsValueType <Node> >(root.Height));
}
this.ResetStack();
}
}
/// <summary>
/// Disposes of this enumerator and returns the stack reference to the resource pool.
/// </summary>
public void Dispose()
{
_root = null !;
_current = null;
if (_stack != null && _stack.TryUse(ref this, out Stack <RefAsValueType <Node> >?stack))
{
stack.ClearFastWhenEmpty();
SecureObjectPool <Stack <RefAsValueType <Node> >, Enumerator> .TryAdd(this, _stack !);
}
_stack = null;
}
/// <summary>
/// Initializes an <see cref="Enumerator"/> structure.
/// </summary>
/// <param name="root">The root of the set to be enumerated.</param>
internal Enumerator(SortedInt32KeyNode <TValue> root)
{
Requires.NotNull(root, nameof(root));
_root = root;
_current = null;
_poolUserId = SecureObjectPool.NewId();
_stack = null;
if (!_root.IsEmpty)
{
if (!s_enumeratingStacks.TryTake(this, out _stack))
{
_stack = s_enumeratingStacks.PrepNew(this, new Stack <RefAsValueType <SortedInt32KeyNode <TValue> > >(root.Height));
}
this.PushLeft(_root);
}
}
/// <summary>
/// Initializes an <see cref="Enumerator"/> structure.
/// </summary>
/// <param name="root">The root of the set to be enumerated.</param>
/// <param name="builder">The builder, if applicable.</param>
/// <param name="reverse"><c>true</c> to enumerate the collection in reverse.</param>
internal Enumerator(Node root, Builder builder = null, bool reverse = false)
{
Requires.NotNull(root, nameof(root));
_root = root;
_builder = builder;
_current = null;
_reverse = reverse;
_enumeratingBuilderVersion = builder != null ? builder.Version : -1;
_poolUserId = SecureObjectPool.NewId();
_stack = null;
if (!s_enumeratingStacks.TryTake(this, out _stack))
{
_stack = s_enumeratingStacks.PrepNew(this, new Stack <RefAsValueType <Node> >(root.Height));
}
this.PushNext(_root);
}
/// <summary>
/// Initializes an Enumerator structure.
/// </summary>
/// <param name="root">The root of the set to be enumerated.</param>
internal Enumerator(SortedInt32KeyNode <TValue> root)
{
Requires.NotNull(root, "root");
this.root = root;
this.current = null;
this.poolUserId = SecureObjectPool.NewId();
this.stack = null;
if (!this.root.IsEmpty)
{
if (!enumeratingStacks.TryTake(this, out this.stack))
{
this.stack = enumeratingStacks.PrepNew(this, new Stack <RefAsValueType <SortedInt32KeyNode <TValue> > >(root.Height));
}
this.PushLeft(this.root);
}
}
/// <summary>
/// Initializes an <see cref="Enumerator"/> structure.
/// </summary>
/// <param name="root">The root of the set to be enumerated.</param>
/// <param name="builder">The builder, if applicable.</param>
internal Enumerator(Node root, Builder?builder = null)
{
Requires.NotNull(root, nameof(root));
_root = root;
_builder = builder;
_current = null;
_enumeratingBuilderVersion = builder != null ? builder.Version : -1;
_poolUserId = SecureObjectPool.NewId();
_stack = null;
if (!_root.IsEmpty)
{
if (!SecureObjectPool <Stack <RefAsValueType <Node> >, Enumerator> .TryTake(this, out _stack))
{
_stack = SecureObjectPool <Stack <RefAsValueType <Node> >, Enumerator> .PrepNew(this, new Stack <RefAsValueType <Node> >(root.Height));
}
this.PushLeft(_root);
}
}
