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Real-World Event Sourcing: Incorrect definition of input and output (page 27)

dsincl12

dsincl12

Real-World Event Sourcing: Incorrect definition of input and output (page 27)

@autodidaddict

On page 27 it says the following which is misleading:

“In pure functional programming terms, input and output are considered impure, because they are side effects.”

This is not correct, input and output are themselves not impure only the side effects. So this is a bit misleading. A pure function have input and output but with no side effects.

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autodidaddict

autodidaddict

Author of Real-World Event Sourcing with Elixir

Thanks for pointing this out. I’ve clarified the input and output here as interactions with external systems, and not input to functions as parameters.

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