writeln = function(...)
    for i, v in pairs({ ... }) do
        if type(v) == "table" then
            local t = v
            if #v == 0 then
                t = {}
                for k, v in pairs(v) do
                    table.insert(t, k .. ": " .. v)
                end
            end
            io.write("[ " .. table.concat(t, ", ") .. " ]")
        else
            io.write(v)
        end
    end
    io.write("\n")
end

foo = function(...)
    print("Called foo ...")
    for i, arg in pairs({ ... }) do
        writeln("    args[", i, "] == ", arg)
    end
    print("... foo end")
end

local tup = { 5, 3.14, "hello world", { 5, 10, 15 }, { foo = 5, bar = 10 } }
foo(unpack(tup))