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@goodmami
Last active August 29, 2015 14:03
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Using the send() function of a Python generator to approximate lookahead and other uses
def regenerator(gen):
for x in gen:
regen = (yield x)
while regen is not None:
yield None # send() also yields something, so don't pull from gen again
regen = (yield regen)
gen = (i for i in range(10))
regen = regenerator(gen)
v = next(regen) # 0
regen.send(v) # we've seen it, but we want to unsee it; send it back
next(regen) # still 0
regen.send(-1) # you don't have to send back the same value
next(regen) # -1
next(regen) # 1 (back to where we left off)
regen.send(None) # yields 2, because None is the same as when send() is not used
next(regen) # 3
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