[Haskell-cafe] about integer and float operations

[Manlio Perillo]

Max Rabkin ha scritto:
> [...]
>
> Then we can define
>     (/.) :: (Real a1, Real a2, Fractional a) => a1 -> a2 -> a
>     x /. y = fromRational $ toRational x / toRational y
 > [...]
> 
> (//) :: (Integral b, Real a, Real a1) => a -> a1 -> b
> x // y = floor $ toRational x / toRational y
> 
> Hope that helps,
> Max
> 

Yes, thanks.

However there is still a *big* problem: it is inefficient.

Here is a Python version of the Chudnovsky algorithm [1] for computing Pi:
http://paste.pocoo.org/show/102800/

On my system it takes 10 seconds.

Here is an Haskell version:
http://paste.pocoo.org/show/102801/

On my system it takes 30 seconds.



Thanks   Manlio Perillo



[1] 
http://upload.wikimedia.org/math/6/6/8/6681cd21f3ca9bf13248a87d4202e06a.png