Is there any performance value in creating local copies of Lua functions?

Question

Is there any value in creating local copies of common Lua functions like print(), pairs() or ipairs()?

Example:

Answer 1

This is an example in Lua Programing Gems:

Access to external locals (that is, variables that are local to an enclosing function) is not as fast as access to local variables, but it is still faster than access to globals. Consider the next fragment:

function foo (x)
  for i = 1, 1000000 do
    x = x + math.sin(i)
  end
  return x
end
print(foo(10))

We can optimize it by declaring sin once, outside function foo:

local sin = math.sin
function foo (x)
  for i = 1, 1000000 do
    x = x + sin(i)
  end
  return x
end
print(foo(10))

This second code runs 30% faster than the original one