Binary search trees in Erlang

bst.erl

-module(bst).
-export([bst_create/0, bst_insert/2, bst_search/2]).

bst_create() -> [].

bst_insert(Bst, N) ->
  case Bst of
    [] -> [N, [], []];
    [Root, Lhs, Rhs] ->
      if
        N == Root -> Bst;
        N < Root -> [Root, bst_insert(Lhs, N), Rhs];
        N > Root -> [Root, Lhs, bst_insert(Rhs, N)]
      end
  end.

bst_search(Bst, N) ->
  case Bst of
    [] -> false;
    [Root, Lhs, Rhs] ->
      if
        N == Root -> true;
        N < Root -> bst_search(Lhs, N);
        N > Root -> bst_search(Rhs, N)
      end
  end.