using less stack

[Jon Fairbairn]

> Thanks for all the advice. In the end, I couldn't make $! work for me =

> (it always seems to be harder than I think it will be to use it, and $!=
 =

> and deepSeq makes my code run slowly). =


:-(

> But a continuation passing style foldl worked wonderfully.

As Jay Cox pointed out by email, my answer was rot because I
had confused foldl and foldr

> I now have:
> =

>  > cpsfold f a [] =3D a
>  > cpsfold f a (x:xs) =3D f x a (\y -> cpsfold f y xs)
> =

> and f takes a continuation, Bob's my uncle, and I have a program that =

> runs quickly in constant space!

Good.  I'm curious to know from other readers whether
continuations like this are the only way of solving it,
though.

  J=F3n


-- =

J=F3n Fairbairn                                 Jon.Fairbairn@cl.cam.ac.u=
k
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