[ruby-core:117101] [Ruby master Feature#19742] Introduce `Module#anonymous?`

Issue #19742 has been updated by fxn (Xavier Noria).


Now, the name of classes and modules can be one of three things:

1. `nil`
2. Temporary
3. Permanent

Maybe it would make sense to provide matching predicates, say:

1. `mod.anonymous?`
2. `mod.temporary_name?`
3. `mod.permanent_name?`

so that users have an encapsulated way to check the status of the name.

For example, in the Rails code base, logic like this:

```ruby
@controller_path ||= name.delete_suffix("Controller").underscore unless anonymous?
```

could be rewritten as

```ruby
@controller_path ||= name.delete_suffix("Controller").underscore if permanent_name?
```

What do you think?

----------------------------------------
Feature #19742: Introduce `Module#anonymous?`
https://bugs.ruby-lang.org/issues/19742#change-107174

* Author: ioquatix (Samuel Williams)
* Status: Open
----------------------------------------
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 -- [e-mail]
 To unsubscribe send an email to [e-mail]
 ruby-core info -- https://ml.ruby-lang.org/mailman3/postorius/lists/ruby-core.ml.ruby-lang.org/