Flow.reduce throws an error

Questions / Help
1

Hi Everyone,

I am learning Elixir and i am trying to compile this program but not with success.

Goal: TO sum the list parallely using Flow

defmodule ParallelProcessing do
use Flow
def process_numbers(numbers) do
numbers
|> Flow.reduce(fn → 0 end, &(&1+&2))
|>Enum.to_list()
end
end
numbers = 1…10
result= ParallelProcessing.process_numbers(numbers)
IO.inspect(result)

But the following error is thrown
08:57:35.842 [error] GenServer #PID<0.183.0> terminating
** (Protocol.UndefinedError) protocol Enumerable not implemented for 110 of type Integer, Flow attempted to convert the stage accumulator into events but failed, to explicit convert your current state into events use on_trigger/2

I am using Flow version 1.2.4
Elixir version: 1.13.4, Erlang/OTP 25[erts-13.0.4]

All this is being run from Debian and hence these versions (without using asdf)

Can you guys help please
Sincerely,
Suds

2

Please, next time format your code with triple backticks. The error you get is pretty self explanatory, 110 is not enumerable.Flow.reduce/3 returns a single integer and you call Enum.to_list/1 with it. The integer doesn’t implement the Enumerable protocol.

3

Thanks a lot.
Can you help me to extract this sum from Flow.reduce.
Sincerely,
Suds

4

It’s already there as Flow.reduce/3 returns it.

5

The Problem i face is that when i try to print it the actual value is not displayed. The internal Flow structure with consumers and producers are displayed. I print the value using IO.inspect