assert {
    ok = "hello @" % ("world") == "hello world",
    desc = "\"hello @\" % (\"world\") == \"hello world\"",
};
assert {
    ok = "1 @ @" % (2, 3) == "1 2 3",
    desc = "\"1 @ @\" % (2, 3) == \"1 2 3\"",
};
assert {
    ok = "@ or @" % (true, false) == "true or false",
    desc = "\"@ or @\" % (true, false) == \"true or false\"",
};
assert {
    ok = "@" % (NULL) == "NULL",
    desc = "\"@\" % (NULL) == \"NULL\"",
};