Issue #15857 has been updated by shuujii (Shuji KOBAYASHI).


> > @jeremyevans0 Thank you for your comment. About Complex, I agree with most of v2 patch, but I have some comments.
> >
> > - Should methods from Comparable that are currently disabled be enabled?
>
> I don't think so, but I don't have a strong opinion. If you would like those added, please submit a separate feature request for that.

I don't have a strong opinion, too.

> > About other than Complex, <=> of some classes, such as String and Time, will fail if ~~LHS~~RHS does not implement <=>. It's better to return nil in this case too, because whether it's comparable or not and whether ~~LHS~~RHS implements <=> or not is essentially irrelevant, I think.
>
> I agree, but please submit a separate bug report for that as it is unrelated to Complex#<=>.

Sure. I will create another ticket.

----------------------------------------
Bug #15857: <=> の右辺が <=> を実装していない場合の振る舞い
https://bugs.ruby-lang.org/issues/15857#change-78548

* Author: shuujii (Shuji KOBAYASHI)
* Status: Open
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: ruby 2.6.3p62 (2019-04-16 revision 67580) [x86_64-linux]
* Backport: 2.4: UNKNOWN, 2.5: UNKNOWN, 2.6: UNKNOWN
----------------------------------------
`<=>` の右辺が `<=>` を実装していないとき、`nil` が返却される場合と例外が発生する場合があり一貫性がないように思えるのですが、意図的でしょうか。

```ruby
  0 <=> 0i               #=> NoMethodError (undefined method `<=>' for (0+0i):Complex)
  0 <=> BasicObject.new  #=> nil
 :a <=> 0i               #=> nil
"a" <=> 0i               #=> NoMethodError (undefined method `<=>' for (0+0i):Complex)

```

なお、`0 <=> 0i` に関しては、`0 == 0i` は `true` になるのでそれとも一貫性がないように思えるのもやや気になりました。

---Files--------------------------------
complex-real-spaceship.patch (8.75 KB)
complex-real-spaceship-v2.patch (8.08 KB)
complex-real-spaceship-v3.patch (7.79 KB)


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

Unsubscribe: <mailto:ruby-core-request / ruby-lang.org?subject=unsubscribe>
<http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>