vendor/bundle/ruby/3.4.0/gems/rouge-4.7.0/lib/rouge/demos/fsharp


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(* Binary tree with leaves carrying an integer. *)
type Tree = Leaf of int | Node of Tree * Tree

let rec existsLeaf test tree =
  match tree with
  | Leaf v -> test v
  | Node (left, right) ->
      existsLeaf test left
      || existsLeaf test right

let hasEvenLeaf tree =
  existsLeaf (fun n -> n % 2 = 0) tree