Issue #19304 has been updated by sawa (Tsuyoshi Sawada). @zverok The `Kernel` page is entirely broken from its first sentence:
The `Kernel` module is included by class `Object`, so its methods are available in every Ruby object.
the latter half of which is not true since the introduction of `BasicObject`, and what it claims to be "Public Instance Methods" are not public. It is confusing in the current state. It just needs to be entirely fixed. Fixing this and describing public and private methods correctly would not be confusing. ---------------------------------------- Misc #19304: Kernel vs Object documentation https://bugs.ruby-lang.org/issues/19304#change-101009 * Author: zverok (Victor Shepelev) * Status: Open * Priority: Normal * Assignee: matz (Yukihiro Matsumoto) ---------------------------------------- The restating of the problems raised in #19300, from scratch. I believe it is rather a topic of **community significance** and would be happy if it is possible to **discuss on dev-meeting**, even if the outcome would probably "let's change RDoc in this or that way". So, the problem statement: 1. `Kernel` module defines two "types" of methods: private ones, that pretend to be global (like `puts`), but actually available from inside every object; and public ones (like `#class` or `#frozen?`) that are present in every object including `Kernel`. 2. Since the beginning of times, docs provided an illusion that the second type of the methods belongs to `Object` class, which is, in fact, devoid of its own definitions, just includes `Kernel`. This was handled by special RDoc hack (which, basically, forcefully [reattached definition](https://github.com/ruby/rdoc/blob/017bb9fa496ee0e0959facba694a053008d1ecb0/l...) of public methods if they are defined in `Kernel`, to `Object`) 3. The RDoc hack was working in C code only, so after introduction of `kernel.rb` the illusion started to crumble: methods like `#tap`, `#then`, `#class` [are now documented](https://docs.ruby-lang.org/en/3.2/Kernel.html) as belonging to `Kernel` (breaking the tradition of public methods being documented in `Object`) 4. This is all inconsistent and confusing, and I believe, adds to friction both for newcomers and curious investigators of the language! Additionally, I believe: 1. That the distinction of "two kinds of methods" is useful (saying from a practical experience with explaining Ruby while mentoring, writing articles, and discussing with colleagues) 2. But, considering everything, I agree with what @Eregon and @nobu say in #19300: pretending that methods belong not to the module they really belong to is not the optimal way to document things! So, the options I see (save for "do nothing and let things sort themselves somehow"): 1. Change Ruby's implementation so public methods would really belong to `Object`. Actually, I don't believe anybody would agree to experiment on this scale, so just listing it here for completeness. 2. Just remove the RDoc hack; all methods would belong to `Kernel`, and maybe some introductory free-form text will instruct that they are different. **Pro:** Easy to do. **Contra:** The `Kernel` docs would be super-confusing. 3. Continue to maintain the hack in RDoc and extend it to `kernel.rb` (so methods like `#clone` and `#frozen?` would be still in `Object`). **Pro:** Relatively easy to do, will maintain structure many people used to. **Contra:** This is still a lie, methods belong to `Kernel`, not `Object`. 4. Adjust RDoc to a) be able to separately list **public** and **private** methods in two different lists, and add intro for `Kernel` explaining how to treat those. **Pro:** Probably the best correspondence to reality? **Contra:** Not sure how easy it is to change RDoc this way; and other renderers (like ruby-doc.com and rubyapi.org) would need to adjust themselves. So far, (4) looks the most reasonable (if (1) is 100% impossible, that is!) -- https://bugs.ruby-lang.org/