From: "zverok (Victor Shepelev) via ruby-core" <ruby-core@...>
Date: 2024-11-17T09:44:34+00:00
Subject: [ruby-core:119951] [Ruby master Feature#20770] A *new* pipe operator proposal

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


In case anybody interested, I spent some time on Staruday experimenting on an implementation of @AlexandreMagro���s idea: https://zverok.space/blog/2024-11-16-elixir-pipes.html

```ruby
require 'not_a_pipe'

extend NotAPipe

pipe def repos(username)
  username >>
    "https://api.github.com/users/#{_}/repos" >>
    URI.open >>
    _.read >>
    JSON.parse(symbolize_names: true) >>
    _.map { _1.dig(:full_name) }.first(10) >>
    pp
end
```

It is a ���hack���, but hopefully an interesting one (a macro implemented via AST transformation), and maybe allows to play with different contexts and codebases to see if it fits.

----------------------------------------
Feature #20770: A *new* pipe operator proposal
https://bugs.ruby-lang.org/issues/20770#change-110674

* 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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