From: Davy Brion <ralinx@...>
Date: 2010-09-10T23:02:18+09:00
Subject: calling private accessors

--0015175ce1ecaa39d5048fe83143
Content-Type: text/plain; charset=UTF-8

Hi,

i bumbed into something weird today, and would like to know what's going
on... here's a contrived example:

class Test
  attr_reader :name

  def set_the_name(value)
    name = value
  end

  private

  def name=(value)
    @name = value
  end
end

test = Test.new
test.set_the_name "some name"
p test

the output of this on ruby 1.8.7 (as wel as on 1.9.2) is:

#<Test:0x7fef6dc8>

the name accessor wasn't called, but there was no error either

if i change the set_the_name method to this:

  def set_the_name(value)
    self.name = value
  end

then the output changes to this:

#<Test:0x7fef6da0 @name="some name">

there are two things i don't quite understand about this:
1) i thought private methods should never be called through self, and that
they are implicitely called on self.  calling a non-accessor private method
on self does raise the expected error.  why does the accessor need to be
called using self?
2) when calling the private accessor without using self, its implementation
clearly isn't executed but no exception is raised either... why is that?

--0015175ce1ecaa39d5048fe83143--