Walk Trees

gistfile1.cs

 public static class WalkTreeExtension
    {
        public static void DoWalk<T>(this IEnumerable<T> ienu, Action<T> a, Func<T,IEnumerable<T>> childs)
        {
            foreach(var e in ienu)
            {
                a(e);
                DoWalk(childs(e), a, childs);
            }
        }
        
        public static IEnumerable<Y> TransformTree<T,Y>(this IEnumerable<T> elements, Func<T,Y> transformAction, Func<T, IEnumerable<T>> childsFromElement, Action<Y,Y> addChildToTarget)
        {
            var newTree = new List<Y>();

            foreach (var e in elements)
            {
                var newElement = transformAction(e);
                newTree.Add(newElement);

                foreach (var el in TransformTree(childsFromElement(e), transformAction, childsFromElement,addChildToTarget))
                {
                    addChildToTarget(newElement,el);
                }
            }

            return newTree;
        }
    }