From: "zverok (Victor Shepelev) via ruby-core" <ruby-core@...>
Date: 2024-10-02T17:03:39+00:00
Subject: [ruby-core:119409] [Ruby master Feature#20770] A *new* pipe operator proposal

Issue #20770 has been updated by zverok (Victor Shepelev).


@AlexandreMagro I don���t think this analogy is suitable here. 

Of course, there are operators that aren���t convenient to use in chaining (though, I should admit to the sin of sometimes just using `the.chain.with.+(argument).like.that`, and it works and follows the existing Ruby semantics and intuitions, even if not to everybody���s liking). 

But my point was that the proposed construct is _specifically_ for easier chaining but doesn���t fall in line with any other Ruby���s tool for that. I think a comparison with Elixir demonstrates that. 

In Elixir, you���ll say, ���see, whatever you need to do with the value, just do with more `|>`, it is all the same.��� 

In Ruby, you say ���when you work with collections, you do `.method` and blocks; when you work with methods object already has, you do `.method`; when you need debug print in the middle of the chain, you can `.tap { p _1 }` just like that... But oh, there is also this one nice operator which you can���t mix with anything but it is there too... And it also creates an invisible block like nowhere else, but it is just there for convenience and looking like Elixir, sometimes!���

That���s the major drawback of the proposal in my eyes, and I fail to see a comparably major _gain_.

----------------------------------------
Feature #20770: A *new* pipe operator proposal
https://bugs.ruby-lang.org/issues/20770#change-110024

* Author: AlexandreMagro (Alexandre Magro)
* Status: Open
----------------------------------------
Hello,

This is my first contribution here. I have seen previous discussions around introducing a pipe operator, but it seems the community didn't reach a consensus. I would like to revisit this idea with a simpler approach, more of a syntactic sugar that aligns with how other languages implement the pipe operator, but without making significant changes to Ruby's syntax.

Currently, we often write code like this:

```ruby
value = half(square(add(value, 3)))
```

We can achieve the same result using the `then` method:

```ruby
value = value.then { add(_1, 3) }.then { square(_1) }.then { half(_1) }
```

While `then` helps with readability, we can simplify it further using the proposed pipe operator:

```ruby
value = add(value, 3) |> square(_1) |> half(_1)
```

Moreover, with the upcoming `it` feature in Ruby 3.4 (#18980), the code could look even cleaner:

```ruby
value = add(value, 3) |> square(it) |> half(it)
```

This proposal uses the anonymous block argument `(_1)`, and with `it`, it simplifies the code without introducing complex syntax changes. It would allow us to achieve the same results as in other languages that support pipe operators, but in a way that feels natural to Ruby, using existing constructs like `then` underneath.

I believe this operator would enhance code readability and maintainability, especially in cases where multiple operations are chained together.

Thank you for considering this proposal!






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