title: Running untrusted code in Lua via loadstring
body: <p>I'm working with a modding api for a game, for those curious it's factorio but it's not really relevant, and the Lua environment is HEAVILY limited, blocking functions like <code>setfenv</code>, it's a 5.1 environment and I do have access to loadstring, pcall, etc. My question is how would you recommend running 'unsafe' code that is provided by a user and limiting what functions they can access without access to environment modification functions? (Preferably whitelist functions/values instead of blacklist, but I'll take whatever I can get)</p>