From: jkr...@live.com
To: haskell-cafe@haskell.org
Subject: Tail recursive
Date: Wed, 19 Dec 2012 17:07:14 +0100
Hello,
I need a non tail recursive version of scanl, to produce a large enough list of
>100K vectors (vectors defined as a list)
I have following code:
scanl'::(a -> a -> a) -> a -> [a] -> [a]scanl' f q ls = scanl'' ls (q:[])
where
scanl'' (x:xs) ys = let
h = head ys
x' =
f x h
ys' = x':ys
in h `seq` x' `seq` ys' `seq` scanl''
xs ys'
scanl'' [] ys = ys
If I call this function as below I still got stack-overflow error:
head (scanl' (zipWith (+)) ([0,0]) (take 100000 (repeat [0,1])))
What do I wrong. I am not an experienced Haskell programmer, but find the
behavior quite unexplainable.
Thank for your answer.
RegardsJacq
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