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From: mail@stefanschuessler.de
To: ruby-core@ruby-lang.org
Subject: [ruby-core:91558] [Ruby trunk Feature#15574] Prohibit to pass a block on super() implicitly
Date: Fri, 15 Feb 2019 10:20:40 +0000 (UTC)	[thread overview]
Message-ID: <redmine.journal-76821.20190215102038.ddb2ec14879fbd77@ruby-lang.org> (raw)
In-Reply-To: redmine.issue-15574.20190130071217@ruby-lang.org

Issue #15574 has been updated by sos4nt (Stefan Schüßler).


I prefer the current behavior. Passing along a block is much more common than removing a block.

Let's say I have a class which yields `self` during initialization:

```ruby
class A
  def initialize(foo)
    # ...
    yield self if block_given?
  end
end
```

I can easily subclass the above and add an extra argument via:

```ruby
class B < A
  def initialize(foo, bar = nil)
    # ...
    super(foo)
  end
end
```

I don't even have to know whether `A` takes a block or not, Ruby takes care of it.

With the proposed change however, it becomes my responsibility. Almost every time I use `super(...)` I have to remember passing the block. The above code would become:

```ruby
class B < A
  def initialize(foo, bar = nil, &block)
    # ...
    super(foo, &block)
  end
end
```

Adding an explicit `&block` (and therefore creating a `Proc` object) for the sake of passing it along is something I'd like to avoid.

---

BTW, if you really have to remove all arguments including the block argument, it's merely:

```ruby
super(&nil)
```

That looks just fine to me.

----------------------------------------
Feature #15574: Prohibit to pass a block on super() implicitly
https://bugs.ruby-lang.org/issues/15574#change-76821

* Author: ko1 (Koichi Sasada)
* Status: Open
* Priority: Normal
* Assignee: matz (Yukihiro Matsumoto)
* Target version: 
----------------------------------------
As described in [Feature #15554], `super()` (not `super`) pass the given block.

```
class C
  def foo
    p block_given?
  end
end

class C1 < C
  def foo
    super   #=> true
    super() #=> true
  end
end

C1.new.foo{}
```

`super` (without parameters) passes all passed parameters so it is no surprise to pass given block. 

However, `super()` (with parameters. In this case, it passes 0 parameters) also pass given block implicitly.

I'm not sure who use this behavior, but I think it is simple to prohibit such implicit block passing.




-- 
https://bugs.ruby-lang.org/

  parent reply	other threads:[~2019-02-15 10:20 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <redmine.issue-15574.20190130071217@ruby-lang.org>
2019-01-30  7:12 ` [ruby-core:91332] [Ruby trunk Feature#15574] Prohibit to pass a block on super() implicitly ko1
2019-01-30 10:12 ` [ruby-core:91335] " Webhostingonedollar102
2019-01-30 10:17 ` [ruby-core:91336] " Webhostingonedollar102
2019-01-30 12:12 ` [ruby-core:91338] " eregontp
2019-02-04 18:25 ` [ruby-core:91394] " ruby-core
2019-02-05  2:02 ` [ruby-core:91402] " ko1
2019-02-05  3:27 ` [ruby-core:91403] " duerst
2019-02-05  4:42 ` [ruby-core:91404] " sawadatsuyoshi
2019-02-15 10:20 ` mail [this message]
2019-02-15 10:48 ` [ruby-core:91562] " sawadatsuyoshi
2019-02-15 11:02 ` [ruby-core:91563] " mail
2019-02-15 11:10 ` [ruby-core:91564] " sawadatsuyoshi
2019-02-15 11:42 ` [ruby-core:91566] " eregontp
2019-02-15 11:46 ` [ruby-core:91567] " mail
2019-10-21  8:14 ` [ruby-core:95451] [Ruby master " ko1

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