Feature #6241: Module#method_defined? with inherited flag

• Status: Rejected
• Assignee: matz (Yukihiro Matsumoto)
• Target version: 2.6

[nobu (Nobuyoshi Nakada)]

=begin
Currently (({Module#method_defined?})) does not accept "(({inherited}))" flags as (({Module#instance_methods})) and others.
To tell if a method is defined at an exact class/module, we have to use bad idiom:

mod.instance_methods(false).include?(:foo)

So I propose to let (({method_defined?})) and etc accept the flag.
=end

[nobu (Nobuyoshi Nakada)]

• Tracker changed from Bug to Feature

[trans (Thomas Sawyer)]

I think this is certainly a good idea. But I want to also point out that it's not always ideal either b/c #method_defined? reports false for private/protected methods. So in cases where the method in question might not have known visibility one would have to do:

if method_defined?(:foo) or private_method_defined?(:foo) or protected_method_defined?(:foo)

which sucks. Of course, this has always been an issue with #instance_methods too.

Perhaps now that named parameters are coming into their own, the interface should be modified to handle options?

method_defined?(:foo, all: true, inherited: false)

[matz (Yukihiro Matsumoto)]

• Status changed from Assigned to Rejected
• Target version changed from 2.0.0 to 2.6

Tomas has a point. We cannot accept the original idea.
So I reject this proposal. Try again.

In general I am not a big fun of inherited flag, since most inheritance works rather as composition in Ruby.

Matz.