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|
module sieve
// The standard Sieve of Eratosthenes.
//import StdEnv
(+) infixl 6 :: !Int !Int -> Int
(+) a b = code inline {
addI
}
(-) infixl 6 :: !Int !Int -> Int
(-) a b = code inline {
subI
}
(==) infix 4 :: !Int !Int -> Bool
(==) a b = code inline {
eqI
}
(rem) infix 7 :: !Int !Int -> Int
(rem) a b = code inline {
remI
}
fro :: !Int -> [Int]
fro i = [i:fro (i+1)]
take :: Int [a] -> [a]
take 0 _ = []
take n [x:xs] = [x:take (n-1) xs]
NrOfPrimes :== 1000
// The sieve algorithm: generate an infinite list of all primes.
Start = take NrOfPrimes (sieve (fro 2))
where
sieve [prime:rest] = [prime : sieve (filter prime rest)]
filter p [h:tl] | h rem p == 0 = filter p tl
= [h : filter p tl]
filter p [] = []
|
