indent = indent or "\t"

spacing = spacing or ""

return render (t,

function (x)

spacing = spacing .. indent

if x.tag then

local s = "<" .. x.tag

if type (x.attr) == "table" then

for i, v in pairs (x.attr) do

if type (i) ~= "number" then

-- luaexpat gives names of attributes in list elements

s = s .. " " .. tostring (i) .. "=" .. string.format ("%q", tostring (v))

end

end

end

if #x == 0 then

s = s .. " /"

end

s = s .. ">"

return s

end

return ""

end,

function (x)

spacing = string.gsub (spacing, indent .. "$", "")

if x.tag and #x > 0 then

return spacing .. "</" .. x.tag .. ">"

end

return ""

end,

function (s)

s = tostring (s)

s = string.gsub (s, "&([%S]+)",

function (s)

if not string.match (s, "^#?%w+;") then

return "&amp;" .. s

else

return "&" .. s

end

end)

s = string.gsub (s, "<", "&lt;")

s = string.gsub (s, ">", "&gt;")

return s

end,

function (x, i, v, is, vs)

local s = ""

if type (i) == "number" then

s = spacing .. vs

end

return s

end,

function (_, i, _, j)

if type (i) == "number" or type (j) == "number" then

return "\n"

end

return ""

end)