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[fork] Sieve
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| """Translated from Haskell: | |
| let sieve(p:xs) = p : sieve (filter (\ x -> x `mod` p /= 0) xs) in sieve [2..] | |
| """ | |
| from itertools import ifilter | |
| def ints(k): | |
| while True: | |
| yield k | |
| k+=1 | |
| def sieve(g): | |
| p = g.next() | |
| yield p | |
| g = sieve(ifilter(lambda x: x % p != 0, g)) | |
| while True: | |
| yield next(g) | |
| primes = sieve(ints(2)) | |
| # busts stack if +1 | |
| for i in xrange(996): | |
| print next(primes) |
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| """Translated from Haskell: | |
| let sieve(p:xs) = p : sieve (filter (\ x -> x `mod` p /= 0) xs) in sieve [2..] | |
| """ | |
| from itertools import ifilter | |
| def ints(k): | |
| while True: | |
| yield k | |
| k+=1 | |
| # needed due to scoping issues | |
| def make_filter_pred(p): | |
| return lambda x: x % p != 0 | |
| def sieve(g): | |
| while True: | |
| p = g.next() | |
| yield p | |
| g = ifilter(make_filter_pred(p), g) | |
| primes = sieve(ints(2)) | |
| for i in xrange(10000): | |
| print next(primes) |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
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| """Translated from Haskell: | |
| let sieve(p:xs) = p : sieve (filter (\ x -> x `mod` p /= 0) xs) in sieve [2..] | |
| """ | |
| from itertools import ifilter, chain | |
| def ints(k): | |
| while True: | |
| yield k | |
| k+=1 | |
| class sieve(object): | |
| def __init__(self, g): | |
| self.g = g | |
| def __iter__(self): | |
| p = self.g.next() | |
| return chain([p], sieve(ifilter(lambda x: x % p != 0, self.g))) | |
| primes = iter(sieve(ints(2))) | |
| for i in xrange(10000): | |
| print next(primes) |
Also like how you managed to remove tail and head.
Yup, there's no need for head() and tail(), because we already have next(g) or g.next() for the former, and after running the former we've "advanced" the generator so that's tail().
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You're still awake.
This is awesome shit. ;-)