[ruby-core:105600] [Ruby master Feature#13560] Module#attr_ methods return reasonable values

["jeremyevans0 (Jeremy Evans)" <noreply@ruby-lang.org>]

Issue #13560 has been updated by jeremyevans0 (Jeremy Evans).

Status changed from Open to Closed

Support for this was added in Ruby 3.0.

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Feature #13560: Module#attr_ methods return reasonable values
https://bugs.ruby-lang.org/issues/13560#change-94072

* Author: dunrix (Damon Unrix)
* Status: Closed
* Priority: Normal
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Hi,

I'm suggesting all `Module#attr_` [methods](http://ruby-doc.org/core-2.4.1/Module.html#method-i-attr_accessor) should return array of generated method names, instead of useless `nil`.
Make them more concise across `Module` API, corresponding to logic of [`Module#define_method`](http://ruby-doc.org/core-2.4.1/Module.html#method-i-define_method), allow pass as arguments to visibility `public/protected/private` methods etc.

Concerned method names:

* attr_accessor
* attr_reader
* attr_writer

Demonstration example:

```
class LookBeforeYouLeap
  api_meths = attr_accessor :ruby_api
  # api_meths == [:ruby_api, :ruby_api=]
  private *api_meths

  # Or you can pass generated methods directly
  # protected *attr_reader(:ruby_papi, :ruby_cext)
end

# Assignment to temporary local variable `api_meths` does not pollute class'es
# namespace.
```

I'm aware *attr_** methods also create corresponding instance variables, but `Module` API has no use for them, unlike created accessor methods.

In current state, where *attr_** methods return `nil`, it makes class definition more prone to errors, especially at code refactoring:

```
class ExistingWay
  attr_accessor :ruby_api  # result is nil

  # Need write method names manually
  private :ruby_api, :rby_api=  # throws NameError exception when executed

  # Any change of generated accessor methods names require manual rewrite
  # at each visibility method call also.
end
```




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