function receive(prod) print("receive is called") local status,value = coroutine.resume(prod) return valueendfunction send(x,prod) print("send is called") return coroutine.yield(x)endfunction producer() return coroutine.create(function () print("producer is called") while true do print("producer run again")  local x = io.read()  send(x) end end)endfunction filter(prod) return coroutine.create(function () for line = 1,1000 do  print("enter fliter "..line)  local x = receive(prod)  print("receive in filter finished")  x= string.format("%5d %s",line,x)  send(x,prod) end end)endfunction consumer(prod) print("consumer is called") while true do print("consumer run again") local x = receive(prod) print("retrun customer") io.write(x,"/n") endendp = producer()f=filter(p)consumer(f)

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