XPathNodeList.cs

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using System.Collections;
using System.Collections.Generic;
using System.Xml.XPath;
 
namespace System.Xml;
 
internal sealed class XPathNodeList : XmlNodeList
{
    private readonly List<XmlNode> _list;
 
    private readonly XPathNodeIterator _nodeIterator;
 
    private bool _done;
 
    public override int Count
    {
        get
        {
            if (!_done)
            {
                ReadUntil(int.MaxValue);
            }
            return _list.Count;
        }
    }
 
    public XPathNodeList(XPathNodeIterator nodeIterator)
    {
        _nodeIterator = nodeIterator;
        _list = new List<XmlNode>();
        _done = false;
    }
 
    private XmlNode GetNode(XPathNavigator n)
    {
        IHasXmlNode hasXmlNode = (IHasXmlNode)n;
        return hasXmlNode.GetNode();
    }
 
    internal int ReadUntil(int index)
    {
        int num = _list.Count;
        while (!_done && num <= index)
        {
            if (_nodeIterator.MoveNext())
            {
                XmlNode node = GetNode(_nodeIterator.Current);
                if (node != null)
                {
                    _list.Add(node);
                    num++;
                }
                continue;
            }
            _done = true;
            break;
        }
        return num;
    }
 
    public override XmlNode Item(int index)
    {
        if (_list.Count <= index)
        {
            ReadUntil(index);
        }
        if (index < 0 || _list.Count <= index)
        {
            return null;
        }
        return _list[index];
    }
 
    public override IEnumerator GetEnumerator()
    {
        return new XmlNodeListEnumerator(this);
    }
}