public static T FirstOrDefault <T>(this ITreeNode <T> @this, Func <T, bool> predicate, TreeTraverseOrder order, T @default)
{
T result = @default;
TreeExtensions.TryFindFirstParentFirst(@this, predicate, order, ref result);
return(result);
}
private static bool TryFindFirstParentFirst <T>(ITreeNode <T> root, Func <T, bool> predicate, TreeTraverseOrder order, ref T result)
{
if (predicate(root.Data))
{
result = root.Data;
return(true);
}
ITreeNode <T> child = root.FirstChild;
while (child != null)
{
if (TreeExtensions.TryFindFirstParentFirst(child, predicate, order, ref result))
{
return(true);
}
child = child.NextSibling;
}
return(false);
}