[ruby-core:105849] [Ruby master Feature#18273] Class#subclasses
From:
"Eregon (Benoit Daloze)" <noreply@...>
Date:
2021-10-28 11:31:10 UTC
List:
ruby-core #105849
Issue #18273 has been updated by Eregon (Benoit Daloze).
+1 for Class#subclasses, I think it makes sense since we have Class#descendants.
`Class#subclasses` is then also the "complement" of `Class#superclass`,
just like `Class#descendants` is the complement of `Class#ancestors`.
----------------------------------------
Feature #18273: Class#subclasses
https://bugs.ruby-lang.org/issues/18273#change-94388
* Author: byroot (Jean Boussier)
* Status: Open
* Priority: Normal
----------------------------------------
Ref: https://github.com/rails/rails/pull/43481
Something we forgot to mention in [Feature #14394], is either a parameter or another method to only get direct descendants.
Active Support has been offering `Class.subclasses` as:
```ruby
def subclasses
descendants.select { |descendant| descendant.superclass == self }
end
```
It seems a bit silly to grab all descendants and then restrict the list when `Class#descendants` had to do some recursion to get them all in the first place.
### Proposal
We could either implement `Class#subclasses` directly, or accept a parameter in `Class#descendants`, e.g. `descendants(immediate = false)`.
cc @eregon
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