import random
from time import sleep
from transducer._util import empty_iter, prepend
def iterable_source(iterable, target):
"""Convert an iterable into a stream of events.
Args:
iterable: A series of items which will be sent to the target one by one.
target: The target coroutine or sink.
Returns:
An iterator over any remaining items.
"""
it = iter(iterable)
for item in it:
try:
target.send(item)
except StopIteration:
return prepend(item, it)
return empty_iter()
def poisson_source(rate, iterable, target):
"""Send events at random times with uniform probability.
Args:
rate: The average number of events to send per second.
iterable: A series of items which will be sent to the target one by one.
target: The target coroutine or sink.
Returns:
An iterator over any remaining items.
"""
if rate <= 0.0:
raise ValueError("poisson_source rate {} is not positive".format(rate))
it = iter(iterable)
for item in it:
duration = random.expovariate(rate)
sleep(duration)
try:
target.send(item)
except StopIteration:
return prepend(item, it)
return empty_iter()
