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1 files changed, 16 insertions, 0 deletions

diff --git a/progs/demo/primes.hs b/progs/demo/primes.hs
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+++ b/progs/demo/primes.hs
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+-- This program implements Eratosthenes Sieve
+-- to generate prime numbers.
+
+module Main where
+
+primes :: [Int]
+primes = map head (iterate sieve [2 ..])
+
+sieve :: [Int] -> [Int]
+sieve (p:ps) = [x | x <- ps, (x `mod` p) /= 0]
+
+main = appendChan stdout "How many primes? " abort $
+       readChan stdin abort $ \ input ->
+       appendChan stdout (show (take (read (head (lines input))) primes))
+	                 abort done
+