[ruby-core:107381] [Ruby master Bug#11064] #singleton_methods for objects with special singleton_class returns an empty array

Issue #11064 has been updated by matz (Yukihiro Matsumoto).


`nil` does not have its singleton class, but `NilClass` plays the role of the singleton class (since `nil` is the only instance of `NilClass`).
So a singleton method definition defines a method in `NilClass`. It's a kind of special treatment of singleton methods. Same for `true` and `false`.
We have several options:

* keep the behavior as it is, since `nil` does not have a singleton class
* `nil.singleton_methods` should return methods defined in `NilClass` (same for `TrueClass` and `FalseClass`)

Both have their own trade-offs. Either is OK for me but I slightly prefer the former, since it's easier.

Matz.



----------------------------------------
Bug #11064: #singleton_methods for objects with special singleton_class returns an empty array
https://bugs.ruby-lang.org/issues/11064#change-96283

* Author: rbjl (Jan Lelis)
* Status: Open
* Priority: Normal
* ruby -v: ruby 2.2.1p85 (2015-02-26 revision 49769) [x86_64-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
----------------------------------------
~~~
def nil.bla
  42  
end

# works
nil.bla #=> 42
nil.singleton_method(:bla) #=> #<Method: NilClass#bla>
NilClass.instance_methods.include? :bla #=> true

# does not work
nil.singleton_methods #=> []
~~~




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