describe("Ops compare", {
    describe("Container", {
        test_that("comparison operations work for Container objects", {
            # Simple elements
            co1 <- container(1)
            co2 <- container(2)
            co3 <- container(3)
            co12 <- container(1, 2)
            co21 <- container(2, 1)
            co123 <- container(1, 2, 3)
            expect_error(container(1, 2, 3) < 1:4, "both arguments must be iterable")

            expect_false(co123 < co123)
            expect_false(co123 > co123)
            expect_true(co123 <= co123)
            expect_true(co123 >= co123)
            expect_true(co123 == co123)
            expect_true(co1 != co12)
            expect_true(co1 < co12)
            expect_false(co2 < co12)
            expect_true(co12 < co123)
            expect_true(co12 < co2)

            # Nested containers
            coco0 <- container(0, co3)
            coco1 <- container(1, co12)
            coco2 <- container(1, co21)

            expect_true(coco1 < coco2)
            expect_true(coco2 > coco1)
            expect_true(coco1 != coco2)
            expect_true(coco0 < coco1)
            expect_true(container(1, co12) < container(1, co123))
            expect_false(container(1, co123) < container(1, co123))
            expect_true(container(1, co123) <= container(1, co123))
        })
    })

    describe("Set", {
        test_that("comparison operations work for Set objects", {
            # simple sets
            x <- setnew(1, 2,    "1", "2")
            y <- setnew(   2, 3,      "2", "3")
            expect_true(x > setnew())
            expect_true(setnew() < x)
            expect_true(x != setnew())
            expect_false(x == setnew())
            expect_false(x < x)
            expect_false(x > x)
            expect_true(x == x)
            expect_false(x != x)
            expect_true(x <= x)
            expect_true(x >= x)
            expect_true(x != y)
            expect_true(y != x)
            expect_true(x < y)

            expect_false(x > y)
            expect_false(y < x)
            expect_true(y > x)
            expect_true(x <= y)
            expect_false(x >= y)
            expect_false(y <= x)
            expect_true(y >= x)

            x <- setnew(1)
            y <- setnew(1, "1")
            expect_true(x != y)

            x <- setnew(1)
            y <- setnew(1, 2)
            expect_true(x < y)
            expect_true(x <= y)
            expect_true(y > x)
            expect_true(y >= y)

            # nested sets
            s <- setnew(2, 3)
            x <- setnew(1, setnew(2, 3))
            y <- setnew(1, setnew(3, 2))
            expect_false(x == y)
            x <- setnew(1, s)
            y <- setnew(1, s)
            expect_true(x == y)

            # sets with nested containers
            x <- setnew(1, container(2, deque(3)), 4)
            y <- setnew(1, container(2, deque(3)), 4)
            expect_true(x == y)
            expect_true(x <= y)
            expect_true(x >= y)
            expect_false(x < y)
            expect_false(x > y)

            y <- setnew(1, container(deque(3), 2), 4)
            expect_false(x == y) # order in container plays a role

            y <- setnew(1, container(2, deque(4)), 4)
            expect_true(x != y)
            expect_true(x < y)

            y <- setnew(1, container(2, deque(3)))
            expect_false(x == y)
            expect_true(x > y)
        })
    })

    describe("Relational", {
        test_that("relational operations work correctly", {
            s0   <- setnew()
            s1   <- setnew(1)
            s12  <- setnew(1, 2)
            s23  <- setnew(   2, 3)
            s1_3 <- setnew(1,    3)
            s123 <- setnew(1, 2, 3)

            expect_equal(s0 & s0, s0)

            original_sets_were_not_altered <-
                isTRUE(all.equal(s0,   setnew()))           &&
                isTRUE(all.equal(s1,   setnew(1)))          &&
                isTRUE(all.equal(s12,  setnew(1, 2)))       &&
                isTRUE(all.equal(s23,  setnew(   2, 3)))    &&
                isTRUE(all.equal(s1_3, setnew(1,   3)))     &&
                isTRUE(all.equal(s123, setnew(1, 2, 3)))

            expect_true(original_sets_were_not_altered)
        })
    })
})