Fuzion • Idioms • Idiom # 128: Breadth-first traversing of a tree

Idiom # 128: Breadth-first traversing of a tree

Code

Complete Example

ex128 is

  node(name String, children Sequence node) is

  breadth_first_traverse(f node -> unit, root node) =>
    breadth_first_traverse(queue Sequence node) unit =>
      match queue.as_list
        nil =>
        c Cons =>
          f c.head
          breadth_first_traverse (c.tail ++ c.head.children)
    breadth_first_traverse [root]

  # World
  # ├─Europe
  # │ ├─Belarous
  # │ ├─Portugal
  # ├─Asia
  # ├─Oceania
  # NYI type inference: [] should work for (list node).empty
  five := node "Belarus" (list node).empty
  six := node "Portugal" (list node).empty
  two := node "Europe" [five, six]
  three := node "Asia" (list node).empty
  four := node "Oceania" (list node).empty
  one := node "World" [two, three, four]

  breadth_first_traverse (node -> say node.name) one

What are effects?

last changed: 2025-05-13

next: Idiom # 129: Breadth-first traversing in a graph