/// <summary>
/// Tests if <paramref name="tree"/> has a child with key <paramref name="key"/>.
///
/// If <paramref name="key"/> is null, then returns always false.
/// </summary>
/// <param name="tree"></param>
/// <param name="key"></param>
/// <returns></returns>
public static bool HasChild(this ILineTree tree, ILine key)
{
if (key == null)
{
return(false);
}
if (!tree.HasChildren)
{
return(false);
}
IEnumerable <ILineTree> children = tree.GetChildren(key);
if (children == null)
{
return(false);
}
return(children.Count() > 0);
}
/// <summary> /// Search child by key. /// </summary> /// <param name="tree"></param> /// <param name="key"></param> /// <returns>child node or null if was not found</returns> public static ILineTree GetChild(this ILineTree tree, ILine key) => tree.GetChildren(key)?.FirstOrDefault();
