Re: Recursive anonymous functions?
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- Subject: Re: Recursive anonymous functions?
- From: Rici Lake <lua@...>
- Date: 2004年7月22日 21:58:05 -0500
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