Re: Recursive anonymous functions?

[Rici Lake <lua@...>]

On 22-Jul-04, at 9:31 PM, Gabor Grothendieck wrote:
> For example, we can invoke the anonymous factorial function
> evaluating it for the argument 3 like this:
>
>    Recall = function(...)
>      return debug.getinfo(2,"f").func(unpack(arg))
>    end

The use of the debug library is not advisable, unless you are actually 
debugging. Furthermore, this will not work on the tail-recursive 
implementation of factorial:

print ((function(x, acc)
          if x <= 1 then return acc
                    else return Recall(x - 1, x * acc)
          end
        end) (3, 1))

stdin:1: attempt to call field `func' (a nil value)
stack traceback:
        stdin:1: in function `Recall'
        (tail call): ?
        stdin:5: in main chunk
        [C]: ?


---------- Just to confirm:
do
  local function fact(x, acc)
    if x <= 1 then return acc
              else return fact(x - 1, x * acc)
    end
  end
  for i = 1, 10 do print(fact(i, 1)) end
end
==>
1
2
6
24
120
720
5040
40320
362880
3628800