From: "Eregon (Benoit Daloze) via ruby-core" <ruby-core@...>
Date: 2023-06-22T10:38:13+00:00
Subject: [ruby-core:114001] [Ruby master Feature#19742] Introduce `Module#anonymous?`

Issue #19742 has been updated by Eregon (Benoit Daloze).


> I want to use this proposal to discuss this issue and whether there is anything we should do about such behaviour (or even if it's desirable).

I think it would be great to reflect it in the Module#name if a Module is no longer reachable through that name.
Either setting it back to `nil` or something like `#<no longer reachable, was: Foo::Bar>`.

Regarding `Module#anonymous?`, I think it should be true for `Module.new::C = Module.new #=> #<Module:0x00007f92d6c66770>::C` (note, the `.name` of that is `"#<Module:0x00007f92d6c66770>::C"`, it's not nil)
I.e., it should only return `false` if `Module#name` is a valid constant path, i.e., if all components of the the constant path are valid constant names.

----------------------------------------
Feature #19742: Introduce `Module#anonymous?`
https://bugs.ruby-lang.org/issues/19742#change-103659

* Author: ioquatix (Samuel Williams)
* Status: Open
* Priority: Normal
----------------------------------------
As a follow-on <from https://bugs.ruby-lang.org/issues/19521>, I'd like propose we introduce `Module#anonymous?`.

In some situations, like logging/formatting, serialisation/deserialization, debugging or meta-programming, we might like to know if a class is a proper constant or not.

However, this brings about some other issues which might need to be discussed.

After assigning a constant, then removing it, the internal state of Ruby still believes that the class name is permanent, even thought it's no longer true.

e.g.

```
m = Module.new
m.anonymous? # true

M = m
m.anonyomous # false

Object.send(:remove_const, :M)
M # uninitialized constant M (NameError)

m.anonymous? # false
```

Because RCLASS data structure is not updated after the constant is removed, internally the state still has a "permanent class name".

I want to use this proposal to discuss this issue and whether there is anything we should do about such behaviour (or even if it's desirable).

Proposed PR: https://github.com/ruby/ruby/pull/7966

cc @fxn



-- 
https://bugs.ruby-lang.org/
 ______________________________________________
 ruby-core mailing list -- ruby-core@ml.ruby-lang.org
 To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org
 ruby-core info -- https://ml.ruby-lang.org/mailman3/postorius/lists/ruby-core.ml.ruby-lang.org/