def test_dft_reverse(self):
a, b, c, d = Div(), Div(), Div(), Div()
a(b(d), c)
l = list(a.dfs_preorder(reverse=True))
self.assertTrue(l == [a, c, b, d])
l = list(a.dfs_inorder(reverse=True))
self.assertTrue(l == [c, a, d, b])
l = list(a.dfs_postorder(reverse=True))
self.assertTrue(l == [c, d, b, a])
def test_dft(self):
a, b, c, d = Div(), Div(), Div(), Div()
a(b(d), c)
l = list(a.dfs_preorder())
self.assertTrue(l == [a, b, d, c])
l = list(a.dfs_inorder())
self.assertTrue(l == [d, b, a, c])
l = list(a.dfs_postorder())
self.assertTrue(l == [d, b, c, a])
