Feature #19871
closedAdd __owner__
Description
Which will give the owner of the currently executing method.
method(__method__).owner
or method(__callee__).owner
isn't enough since it may return a different owner if the method is overridden.
Relying on calling the name of its owner is also theoretically not reliable since the constant can be overshadowed and it makes code less portable when moving it from one namespace to another.
Updated by konsolebox (K B) 11 months ago
The changes needed to implement this turned out to be just simple so I went ahead and just created a PR in https://github.com/ruby/ruby/pull/8411.
The difference between using method(__method__).owner
and using __owner__
can be demonstrated in the following code:
module M
C = 1234
def m
puts "method(__method__).owner: #{method(__method__).owner}"
puts "method(__method__).owner::C: #{method(__method__).owner::C}"
puts "__owner__: #{__owner__}"
puts "__owner__::C: #{__owner__::C}"
end
end
class N
include M
C = 5678
def m
super
end
end
N.new.m
Output:
method(__method__).owner: N
method(__method__).owner::C: 5678
__owner__: M
__owner__::C: 1234
Updated by mame (Yusuke Endoh) 11 months ago
Could you explain the use case?
Updated by nobu (Nobuyoshi Nakada) 11 months ago
Why not use the constant without scopes?
module M
C = 1234
def m
puts "C: #{C}" #=> C: 1234
end
end
Updated by konsolebox (K B) 11 months ago
nobu (Nobuyoshi Nakada) wrote in #note-3:
Why not use the constant without scopes?
module M C = 1234 def m puts "C: #{C}" #=> C: 1234 end end
I was expecting the lookup to still be affected by the inheriting class. I should have tested it first.
I guess this invalidates the feature request.
Updated by konsolebox (K B) 11 months ago
mame (Yusuke Endoh) wrote in #note-2:
Could you explain the use case?
It's supposed to make sure a general-use module can be implemented purely and can't be tainted by any of its inheritors, unless it's deliberately patched of course.
But as I have just discovered, without scopes a constant will remain as the constant that is accessed expectedly.
Updated by Eregon (Benoit Daloze) 11 months ago
- Status changed from Open to Rejected