func Preload(L *lua.LState) {
	L.PreloadModule("tac", Loader)
}
Preload adds tac to the given Lua state's package.preload table. After it
has been preloaded, it can be loaded using require:

local tac = require("tac")
package tac
import (
	lua "github.com/yuin/gopher-lua"
)