def stage(func, next_stage, validate):
"""Stage: both (yield) and .send."""
data = None
with close_on_exit(next_stage):
while True:
data = (yield data)
data = func(data)
if validate(data):
data = next_stage.send(data)
def Producer(func, next_stage, validate):
"""Producer: only .send (and yield as entry point)."""
state = (yield) # get initial state
with close_on_exit(next_stage):
while True:
try:
res, state = func(state)
except StopPipeline:
return
if validate(res):
yield next_stage.send(res)