[ruby-core:93424] [Ruby trunk Feature#15799] pipeline operator

Issue #15799 has been updated by Eregon (Benoit Daloze).


inopinatus (Joshua GOODALL) wrote:
> ``` ruby
> result = 3 |> pow(2) #=> 9
> result #=> 3 (!?!?!)
> ```

This makes it clear to me: the pipeline operator just seems a hack to avoid parentheses around Range literals.
The precedence seems not intuitive.
Unlike `and`, where `if a = 3*2 and a == 6` is rather clear, here assignment before |> is never wanted.
So probably assignment before |> should be a SyntaxError.

This syntax saves Range literal parenthesis, but it doesn't even save characters, so I see not point for it as it is.

Others will say it's nice for multi-line method call chains, but `.` works just fine in that case too when using indentation:
```ruby
1..
|> take 10
|> each { |x| p x }

(1..)
  .take(10)
  .each { |x| p x }
```
(the example is from @mame's post)

Finally, as other have said, the most essential operator of OO languages, the method call operator, does not need to be reinvented, `.` works just fine.

----------------------------------------
Feature #15799: pipeline operator
https://bugs.ruby-lang.org/issues/15799#change-78966

* Author: nobu (Nobuyoshi Nakada)
* Status: Closed
* Priority: Normal
* Assignee: 
* Target version: 
----------------------------------------
Implemented the pipeline operator `|>`, a topic of "ruby committers vs the world" in RubyKaigi 2019.
Also a casual idea of rightward assignment.

```ruby
1.. |> take 10 |> map {|e| e*2} |> (x)
p x #=> [2, 4, 6, 8, 10, 12, 14, 16, 18, 20]
```

https://github.com/nobu/ruby/tree/feature/pipeline




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