(Difference between revisions)
Revision as of 09:43, 29 August 2011
I'm interested in Haskell.
I like this:
-- inifinte folding idea due to Richard Bird -- double staged production idea due to Melissa O'Neill -- tree folding idea Dave Bayer / simplified formulation Will Ness primes = 2 : g (fix g) where g ps = 3 : gaps 5 (foldi (\(q:qs) -> (q:) . union qs) [[p*p, p*p+2*p..] | p <- ps]) gaps k s@(c:t) | k < c = k : gaps (k+2) s -- | k<=c = minus [k,k+2..] s | True = gaps (k+2) t -- fused to avoid a space leak fix g = xs where xs = g xs -- global defn to avoid space leak
Also, the math formula for Sieve of Eratosthenes,
- . . . or, :) :) .
Trial division sieve: