local function xml_escape(string)
    return string
end

local function process_tag(table, key, args)
    local middle, k, v, b = ""
    
    args.n = nil

    if type(args[2]) == "table" then
        for k, v in ipairs(args[2]) do
            middle = middle .. v
        end
    elseif type(args[2] == "string") then
        middle = xml_escape(args[2])
    end
    
    if middle ~= "" then
        return "<" .. key .. ">" .. middle .. "</" .. key .. ">"
    else
        return "<" .. key .. "/>"
    end
end

local xmlmarkup_metatable = {
    __index = function(table, key)
        local t, k = table, key
        return function(...) return process_tag(t, k, arg) end
    end
}

function NewXmlMarkup()
    local r = {
        
    }
    
    setmetatable(r, xmlmarkup_metatable)
    
    return r
end

xm = NewXmlMarkup()

s = xm:html {
    xm:head {
        xm:title "Test"
    },
    xm:body {
        xm:b "Bold test."
    }
}

print(s)