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 is
      match queue.asList
        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 Sequences.empty<node>
  five := node "Belarus" Sequences.empty<node>
  six := node "Portugal" Sequences.empty<node>
  two := node "Europe" [five, six]
  three := node "Asia" Sequences.empty<node>
  four := node "Oceania" Sequences.empty<node>
  one := node "World" [two, three, four]

  breadth_first_traverse (node -> say node.name) one

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