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Comment by dvdhnt | Hacker News Reader

Maybe it's just me, but I don't see the purpose of a pipeline operator - at least in JS.

From a cognitive perspective, it doesn't make code more readable or easier to understand.

From a practical perspective, why? What can't we do with it that isn't aesthetic?

Edit: Okay, after reading through the article again, I get it. I've had issues with eager loading in Node AND I will say the pipeline is easier to understand than simply using generators. Good article.

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A simple example would be mixing map/reduce stuff on arrays with other non-built-in utility functions that take arrays without having to break the logical flow.

For a very simple example, manipulating and summing an array of values:

    import { range, sum } from 'ramda';

    range(0, 6)
      |> x => x.map(i => i * i)
      |> sum

Compare to:

    import { range, sum } from 'ramda';

    sum(
      range(0, 6)
        .map(i => i * i)
    )

...and then add three or four other non-builtin methods in between map steps and consider the resulting readability.

I mean, I think one of the big arguments against a pipeline operator is that you can easily roll your own with

  const pipe = (...fxs) => x => fxs.reduce((v, f) => f(v), x);

If you're going to pull in ramda for example, they have their own pipe, and a map function that takes (predicate, array) as curried arguments, to aid with composition import { map, pipe, range, sum } from 'ramda';

    pipe(
      range,
      map(i => i * i),
      sum
    )(0, 6)

I haven't messed with HN formatting before, so I hope that turns out right. My team uses Ramda and pipes regularly in our Node code, and its absolutely wonderful

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