[Haskell-cafe] Re: Simple FAST lazy functional primes

Sjoerd Visscher writes:

Excuse me, 2 doesn't have to be in the list of smaller primes, as we're only generating odd numbers:

primes = 2 : 3 : 5 : 7 : sieve [3] (drop 2 primes) sieve qs@(q:_) (p:ps) = [x | x<-[q*q+2,q*q+4..p*p-2], and [(x`rem`p)/=0 | p<-qs]] ++ sieve (p:qs) ps

Sjoerd

Hi, I've run it now. In producing 100,000 primes, your above code takes x3.5 more time than the one I posted. The code modified as I suggested with (qs++[p]) takes exactly the same time as mine. :) Cheers,