public static IList <TDest> CopyTree <TSrc, TDest>(
TSrc src_root_node,
System.Func <TSrc, IEnumerable <TSrc> > enum_src_children,
System.Func <TSrc, TDest> create_dest_node,
System.Action <TDest, TDest> add_dest_child)
{
var stack = new Stack <TDest>();
var dest_nodes = new List <TDest>();
var walkevents = TreeOps.Walk <TSrc>(src_root_node, input_node => enum_src_children(input_node));
foreach (var ev in walkevents)
{
if (ev.HasEnteredNode)
{
var new_dst_node = create_dest_node(ev.Node);
if (stack.Count > 0)
{
// if there is node on the stack, then that node is the current node's parent
var parent = stack.Peek();
add_dest_child(parent, new_dst_node);
}
else
{
// if there is nothing on the stack this is node without a parent (a root node)
}
stack.Push(new_dst_node);
dest_nodes.Add(new_dst_node);
}
else if (ev.HasExitedNode)
{
stack.Pop();
}
}
return(dest_nodes);
}
public static IEnumerable <T> PreOrder <T>(T root, EnumerateChildren <T> enum_children)
{
return(TreeOps.Walk(root, enum_children).Where(ev => ev.HasEnteredNode).Select(ev => ev.Node));
}