Recreating setfenv() in Lua 5.2

Question

How can I recreate the functionality of setfenv in Lua 5.2? I\'m having some trouble understanding exactly how you are supposed to use the new _ENV

Answer 1

It's a bit expensive, but if it's that important to you...

Why not use string.dump, and re-load the function into the right environment?

function setfenv(f, env)
    return load(string.dump(f), nil, nil, env)
end
function foo()
    herp(derp)
end

setfenv(foo, {herp = print, derp = "Hello, world!"})()