Elixirでエラトステネスの篩を実装してみた ref: http://qiita.com/tamanugi/items/8b97e93f94fdb014100b

erastosthenes.exs

defmodule Erastosthenes do

  def sieve(prime, next, last?) do
    receive do
      n when rem(n, prime) == 0 ->
        sieve(prime, next, last?)
      n ->
        send next, n
        next = if last? do
          # 自身が最後の篩だったら次の篩を生成する
          {pid, _} = spawn_monitor Erastosthenes, :sieve, [n, next, true] 
          pid
        else
          next
        end
        sieve(prime, next, false)
    end
  end

  def output do
    receive do
      n ->
        IO.puts "#{n} is prime."
        output()
    end
  end
end

opid = spawn Erastosthenes, :output, []
{spid, _} = spawn_monitor Erastosthenes, :sieve, [2, opid, true]

2..100
|> Stream.map(&(send spid, &1))
|> Enum.to_list

file1.txt

$ iex
iex(1)> c"erastosthenes.exs"
3 is prime.
5 is prime.
7 is prime.
11 is prime.
13 is prime.
17 is prime.
19 is prime.
23 is prime.
29 is prime.
31 is prime.
37 is prime.
41 is prime.
[Erastosthenes]
43 is prime.
47 is prime.
53 is prime.
59 is prime.
61 is prime.
67 is prime.
71 is prime.
73 is prime.
79 is prime.
83 is prime.
89 is prime.
97 is prime.