20 Sep
2012
20 Sep
'12
1:28 a.m.
On Wed, Sep 19, 2012 at 7:24 PM, <sdiyazg@sjtu.edu.cn> wrote:
main = do let f 0 acc = return acc f n acc = do v <- return 1 f (n-1) (v+acc) f 1000000 100 >>= print
Try this main = do let f :: Int -> Int -> IO Int f 0 !acc = return acc -- note strict accumulator f n acc = do v <- return 1 f (n-1) (v+acc) f 1000000 100 >>= print