[Hugs-users] stack overflow in tail recursive function

Bruno Schneider boschneider at gmail.com
Tue Mar 23 08:01:54 EDT 2010

Hi all,

I have this tail recursive factorial function:

factorial :: Integer -> Integer
factorial 0 = 1
factorial n = fat' n 1 where
    fat' 1 fat = fat
    fat' n fat = fat' (n-1) (n*fat)

Whenever I run it with a number of 20000 or more I get a stack
overflow error. It doesn't seem a problem with the large resulting
number because, if so, the message should be something like "Garbage
collection fails to reclaim sufficient space". Other functions seem to
able to handle a larger number of recursive calls.

So, what is the problem with this particular function?

Bruno Schneider

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