decent_bfs.fsx

decent_bfs.fsx

type Tree<'a> = { value: 'a; children: Tree<'a> list }

let rec levels (ts: Tree<'a> list) =
  match ts with
  | [] -> []
  | _ ->
    let xs, chls = ts |> List.map (fun t -> t.value, t.children) |> List.unzip
    let subs = chls |> List.concat |> levels
    xs :: subs


[ { value = 1
    children =
      [ { value = 2
          children =
            [ { value = 5
                children = [ { value = 6; children = [] } ] } ] }
        { value = 3
          children =
            [ { value = 4
                children = [ { value = 7; children = [] } ] } ] } ] } ]
|> levels
|> List.iter (fun xs -> printfn $"{xs}")