Strange, when I run your code I don't get 9 or 15 On Thu Feb 12 2015 at 11:02:00 AM Jorge Marques Pelizzoni < jorge.pelizz...@gmail.com> wrote:
> Hi, there! Please bear with me as I am very new to Closure (this is my > second program ever) but have a kind of solid Haskell background. > > I was trying to get a version of this Haskell code: > > divides x y = mod x y == 0 > primeub x = div x (if even x then 2 else 3) > isprime primes x = all (not . divides x) (lowerprimes x) > where > lowerprimes x = takeWhile (<= primeub x) primes > > primes = 2 : filter (isprime primes) [3..] > > > which works fine. E.g.: take 10 primes == [2,3,5,7,11,13,17,19,23,29]. In > Closure, I got this: > > (defn divides? [x y] (zero? (mod x y))) > (defn prime-ub [x] (/ x (if (even? x) 2 3))) > (defn lower-primes [primes x] (let [ub (prime-ub x)] > (take-while #(<= % ub) primes))) > (defn prime? [primes x] (not-any? #(divides? x %)(lower-primes primes x))) > > (defn primes [] (let [primes' (atom nil)] > (reset! primes' (cons 2 (filter #(prime? @primes' %) > (drop 3 (range))))))) > > However, I am getting (take 10 (primes)) == (2 3 5 7 9 11 13 15 17 19) > (please notice the undesirable presence of 9 and 15 there...). > > Any ideas why this is happening? Thanks in advance. > > > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
