Hello Haskell-ers,
So a friend and I were thinking about making code faster in Haskell, and I
was wondering if there was a way to improve the following method of
generating the list of all prime numbers. It takes about 13 seconds to run,
meanwhile my friend's C version took 0.1. I'd love to
There are many things that makes your code slow.
* The default for Haskell is to compute with Integer, not Int. So
that makes from Integral and floor very slow.
* foldl' is a bad choice, because it is too strict, you want to abort
the loop as soon as possible.
* your take is really wrong.
On 2/10/07, Lennart Augustsson [EMAIL PROTECTED] wrote:
There are many things that makes your code slow.
* The default for Haskell is to compute with Integer, not Int. So
that makes from Integral and floor very slow.
* foldl' is a bad choice, because it is too strict, you want to abort
the
Gah! Gmail has really broken defaults for posting to lists.
On 10/02/07, Creighton Hogg [EMAIL PROTECTED] wrote:
Hello Haskell-ers,
So a friend and I were thinking about making code faster in Haskell, and I
was wondering if there was a way to improve the following method of
generating the list
On 2/10/07, Creighton Hogg [EMAIL PROTECTED] wrote:
On 2/10/07, Lennart Augustsson [EMAIL PROTECTED] wrote:
There are many things that makes your code slow.
* The default for Haskell is to compute with Integer, not Int. So
that makes from Integral and floor very slow.
* foldl' is a bad
On 2/10/07, Peter Berry [EMAIL PROTECTED] wrote:
Gah! Gmail has really broken defaults for posting to lists.
On 10/02/07, Creighton Hogg [EMAIL PROTECTED] wrote:
Hello Haskell-ers,
So a friend and I were thinking about making code faster in Haskell, and
I
was wondering if there was a way to
Yeah, the 1 first primes takes about 0.1 seconds in Haskell too
using the code I posted.
On Feb 10, 2007, at 21:49 , Creighton Hogg wrote:
On 2/10/07, Peter Berry [EMAIL PROTECTED] wrote: Gah! Gmail has
really broken defaults for posting to lists.
On 10/02/07, Creighton Hogg [EMAIL
Hello Creighton,
Sunday, February 11, 2007, 12:02:09 AM, you wrote:
import Data.List
primes = 2:(foldr (\x y - if isPrime x then x:y else y) [] [3..])
where isPrime x = foldl' (\z y - z (if x `mod` y == 0 then
False else True)) True (take (floor $ sqrt $ fromIntegral x) primes)
my
