Why ??

[Kyung won Cheon]

## in irb


## in test.rb

p self # => main
def why?
end
self.why? # private method 'why?' called for main:Object
(NoMethodError)


## Anyway, one more..

## in test2.rb

def why?
end

class A
end

p A.private_method_defined?why?) # true


# How is 'why?' inherited???
# The 'main' is a instance of Object but it's not a Object?

# I understand if ...
# class Object
# private
# def why?
# end
# end

##############
# Help Me^^
##############

 

[Trans]

## in irb



=3D> nil

## in test.rb

p self =A0 =A0 =A0 =A0# =3D> main
def why?
end
self.why? =A0 =A0 # private method 'why?' called for main:Object
(NoMethodError)

## Anyway, one more..

## in test2.rb

def why?
end

class A
end

p A.private_method_defined?why?) # true

# How is 'why?' inherited???
# The 'main' is a instance of Object but it's not a Object?

# I understand if ...
# class Object
# =A0 private
# =A0 def why?
# =A0 end
# end

##############
# Help Me^^
##############

The toplevel object (aka 'main') delegates some module-equivalent
methods to Object class. So when you say

def why?
end

What actually happens is:

class Object
def why?
end
private :why?
end

Not all module methods are delegated, try using define_methodwhy?)
at the toplevel instead and it will bomb.

T.

P.S. Personally, I find the whole setup rather half-baked, and have
continually advocated for the replacement of the current toplevel
object with a self extended module.

 

[Sebastian Hungerecker]

The toplevel object (aka 'main') delegates some module-equivalent
methods to Object class.

As far as I'm aware it "delegates" only alias, undef, def, module and class.
So it only delegates keywords, not methods. Which is, I assume, why def works
and define_method (which is a method) does not.

HTH,
Sebastian

 

[Trans]

As far as I'm aware it "delegates" only alias, undef, def, module and cla= ss.
So it only delegates keywords, not methods. Which is, I assume, why def w= orks
and define_method (which is a method) does not.

Good point. I never really looked at like that b/c I tend to think of
keywords as syntax sugar for real methods.

class -> Class.new
def -> define_method
alias -> alias_method
etc.

Conditionals are an exception, of course.

But it sort of begs the question, why does it support the one and not
the other?

T.