22 Jun
2023
22 Jun
'23
1:42 a.m.
Issue #19742 has been updated by fxn (Xavier Noria).
Oh, I thought you meant that the module has a name and had not been assigned to a
constant.
If the module has a name, then not being considered to be anonymous is the least
surprising definition to me.
You could also have
```ruby
class C
def self.name
nil
end
end
```
However, I think overriding such a core method for an attribute that is out of reach,
managed internally by Ruby, is questionable and predicates may be well-defined for the
common case, and obviate situations like this. With this definition, can you say an
anonymous module was never assigned to a constant? No, no more. However, you can add
"without an overwritten name" to make the statement hold.
We could say that an empty array has 0 size. Can people override `Array#size` to return 7?
Yes, they can. But API docs do not need to cover such possibilities. If you override,
you're on your own with the consequences.
----------------------------------------
Feature #19742: Introduce `Module#anonymous?`
https://bugs.ruby-lang.org/issues/19742#change-103648
* Author: ioquatix (Samuel Williams)
* Status: Open
* Priority: Normal
----------------------------------------
As a follow-on <from https://bugs.ruby-lang.org/issues/19521>gt;, 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
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