# ------------------------------------------------
# Simple Producer/Consumer
# ------------------------------------------------
# Connect a simple counting task and a printing task
# together using continuations.
#
# Usage:  count(limit)

def count_task(count, consumer)
    (1..count).each do
        |i|
        callcc {|cc| consumer.call cc, i }
    end
    nil
end

def print_task()
    producer, i = callcc { |cc| return cc }
    print "#{i} "
    callcc { |cc| producer.call }
end

def count(limit)
    count_task(limit, print_task())
    print "\n"
end

# ------------------------------------------------
# Filtering Out Multiples of a Given Number
# ------------------------------------------------
# Create a filter that is both a consumer and producer.
# Insert it between the counting task and the printing task.
#
# Usage:  omit (2, limit)

def filter_task(factor, consumer)
    producer, i = callcc { |cc| return cc }
    if (i%factor) != 0 then
        callcc { |cc| consumer.call cc, i }
    end
    producer.call
end

def omit(factor, limit)
    printer = print_task()
    filter = filter_task(factor, printer)
    count_task(limit, filter)
    print "\n"
end

# ------------------------------------------------
# Prime Number Generator
# ------------------------------------------------
# Create a prime number generator. When a new prime
# number is discovered, dynamically add a new multiple
# filter to the chain of producers and consumers.
#
# Usage:  primes (limit)

def prime_task(consumer)
    producer, i = callcc { |cc| return cc }
    if i >= 2 then
        callcc { |cc| consumer.call cc, i }
        consumer = filter_task(i, consumer)
    end
    producer.call
end

def primes(limit)
    printer = print_task()
    primes = prime_task(printer)
    count_task(limit, primes)
    print "\n"
end