igrigorik/agent

Switch branches/tags
Nothing to show
Fetching contributors…
Cannot retrieve contributors at this time
150 lines (117 sloc) 2.66 KB
 require "spec_helper" describe "sieve of Eratosthenes" do # http://golang.org/doc/go_tutorial.html#tmp_353 it "should work using Channel primitives" do # send the sequence 2,3,4, ... to returned channel def generate(channels) ch = channel!(Integer) channels << ch go!{ i = 1; loop { ch << i+= 1} } return ch end # filter out input values divisible by *prime*, send rest to returned channel def filter(in_channel, prime, channels) out = channel!(Integer) channels << out go! do loop do i, _ = in_channel.receive out << i if (i % prime) != 0 end end return out end def sieve(channels) out = channel!(Integer) channels << out go! do ch = generate(channels) loop do prime, _ = ch.receive out << prime ch = filter(ch, prime, channels) end end return out end # run the sieve n = 20 nth = false channels = [] primes = sieve(channels) result = [] if nth n.times { primes.receive } puts primes.receive[0] else loop do p, _ = primes.receive if p <= n result << p else break end end end expect(result).to eq([2,3,5,7,11,13,17,19]) channels.each(&:close) end it "should work with Ruby blocks" do # send the sequence 2,3,4, ... to returned channel generate = Proc.new do |channels| ch = channel!(Integer) channels << ch go! do i = 1 loop { ch << i+= 1 } end ch end # filter out input values divisible by *prime*, send rest to returned channel filtr = Proc.new do |in_channel, prime, channels| out = channel!(Integer) channels << out go! do loop do i, _ = in_channel.receive out << i if (i % prime) != 0 end end out end sieve = Proc.new do |channels| out = channel!(Integer) channels << out go! do ch = generate.call(channels) loop do prime, _ = ch.receive out << prime ch = filtr.call(ch, prime, channels) end end out end # run the sieve n = 20 nth = false channels = [] primes = sieve.call(channels) result = [] if nth n.times { primes.receive } puts primes.receive[0] else loop do p, _ = primes.receive if p <= n result << p else break end end end expect(result).to eq([2,3,5,7,11,13,17,19]) channels.each(&:close) end end