/**
* @param tree
* @return
*/
@Pure
@ExtensionMethod
@ReturnNonnull
@Recursive
public static <T> AbstractUnmodifiableIterable<T> NodeValuesPostOrder(final IMultiTree<T> tree) {
com.google.common.base.Preconditions.checkNotNull(tree);
if (tree.IsTreeNode()) {
final IMultiTreeNode<T> treeNode = tree.AsTreeNode();
assert treeNode != null;
return Iterables.Concat(
Iterables.Concat(
Iterables.Map(
treeNode.GetSubtrees(),
new Func1<IMultiTree<T>, Iterable<T>>() {
@Override
public Iterable<T> DoFunc(final IMultiTree<T> input) {
assert input != null;
return MultiTrees.NodeValuesPreOrder(input);
}
})),
treeNode.GetNodeValue());
} else {
assert tree.IsEmptyTree();
return Iterables.EmptyUnmodifiableIterable();
}
}
/**
* @param tree
* @param foldTreeFunc
* @param emptyTreeValue
* @return
*/
@Pure
@ExtensionMethod
@Recursive
public static <TNode, TOut> TOut Fold(
final IMultiTree<? extends TNode> tree,
final Func2<? super TNode, ? super Iterable<TOut>, ? extends TOut> foldTreeFunc,
@Nullable final TOut emptyTreeValue) {
com.google.common.base.Preconditions.checkNotNull(foldTreeFunc);
com.google.common.base.Preconditions.checkNotNull(tree);
if (!tree.IsEmptyTree()) {
final IMultiTreeNode<TNode> multiTreeNode = MultiTrees.AsMultiTreeNodeWhenReadOnly(tree);
assert multiTreeNode != null;
return foldTreeFunc.DoFunc(
multiTreeNode.GetNodeValue(),
Iterables.Map(
multiTreeNode.GetSubtrees(),
new Func1<IMultiTree<TNode>, TOut>() {
@Override
public TOut DoFunc(IMultiTree<TNode> subTree) {
return MultiTrees.Fold(subTree, foldTreeFunc, emptyTreeValue);
}
}));
} else {
return emptyTreeValue;
}
}