function display(arr, indentation_level)
    local indentation_level = indentation_level or 0
    local indentation = string.rep('\t', indentation_level)

    for k,v in pairs(arr) do
        ks = indentation .. k .. ':'
        if type(v) == 'table' then
            print(ks .. '{')
            display(v, indentation_level + 1)
            print(indentation .. '}')
        else
            print(ks, v)
        end
    end
end

-- Showcase.
display({10, 100, 'xyz', a=1, b={q=1, w=2, e=3}})