Anyway, these functions do not get the least fixed point ot r, but a fixed point of f starting from the seed x. it is'n?

http://en.wikipedia.org/wiki/Fixed_point_(mathematics)


2009/3/19 Neil Mitchell <ndmitchell@gmail.com>
> I've used a similar function myself, but why write it in such a complicated
> way? How about
>
> lfp :: Eq a => (a -> a) -> a -> a
> lfp f x
>  | f x == x = x
>  | otherwise = lfp f (f x)

I've used a similar function too, but your version computes f x twice
per iteration, I wrote mine as:
't
fix :: Eq a => (a -> a) -> a -> a
fix f x = if x == x2 then x else fix f x2
   where x2 = f x

I find this fix much more useful than the standard fix.

Thanks

Neil
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