[ruby-core:80732] [Ruby trunk Feature#9453] Return symbols of defined methods for `attr` and friends

Issue #9453 has been updated by matz (Yukihiro Matsumoto).


Yes, `def` and `define_method` returns symbols now.
But it does not mean `attr_*` should return symbols. Since they can define multiple methods.
Considering there's no use for private attributes, I don't think the proposal creates real-world value.

Besides that, mention to the principle of least surprise gives you negative evaluation here (since the background varies from user to user, and it does not lead to constructive discussion).

Matz.


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Feature #9453: Return symbols of defined methods for `attr` and friends
https://bugs.ruby-lang.org/issues/9453#change-64287

* Author: jballanc (Joshua Ballanco)
* Status: Rejected
* Priority: Normal
* Assignee: matz (Yukihiro Matsumoto)
* Target version: 
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With Ruby 2.1 returning a symbol from `def` and `define_method`, that leaves `attr`, `attr_reader`, `attr_writer`, and `attr_accessor` as ways to define methods that still return nil. This is unfortunate, because it prevents the use of method decorators developed to work with `def` from also working with the `attr*` methods. Because these mechanisms can define more than one method, the return values would need to be arrays of symbols.

For an example of how this could be useful in real-world code, consider this sample from James Edward Gray II's Warehouse Keeper example (https://github.com/JEG2/warehouse_keeper):

    attr_reader :images, :key_map, :window, :screen_manager, :animations
    private     :images, :key_map, :window, :screen_manager, :animations

if `attr_reader` returned symbols, then this could be simplified to:

    private *attr_reader(:images, :key_map, :window, :screen_manager, :animations)

I've attached a patch that implements this change and includes a few tests. For those who use git, I've also submitted this as a pull request here: https://github.com/ruby/ruby/pull/517

---Files--------------------------------
attr_rv.patch (3.23 KB)


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