turingprimes.hs

import System.Environment
import Control.Parallel.Strategies

import Math.NumberTheory.Primes.Sieve (primes)
import Math.NumberTheory.Primes.Testing (isPrime)

-- Converts 42d -> 101010d
binread :: Integer -> Integer
binread 0 = 0
binread n = let (q, r) = n `divMod` 2
            in  r + 10 * binread q

turingPrimes :: [(Integer, Bool)]
turingPrimes = map (\ i -> (i, isPrime $ binread i)) primes

main = do
    args <- getArgs
    let bitCount = read $ head args
    let ps       = takeWhile ((< 2^bitCount).fst) turingPrimes
    let par      = ps `using` (parListChunk 100000 rdeepseq)
    print $ length $ filter snd par