At Fri, 13 Oct 2000 12:10:02 +0900,
Shugo Maeda <shugo / ruby-lang.org> wrote:

> > I don't feel it's inconsistent (see `initialize').  It's a matter of
> > choice.  We can choose either a) make it public b) leave private with
> > warning.
> 
> I prefer b because I don't like implicit method visibility
> changes.
> How about others?

I asked shugo a few questions on irc just now.  it turns out that all
private method which ends with `=' is effected with this syntax sugar.
# i didn't know, i must be lucky ;P

# He also told me that it might be possible if we check whether the
# object respond to the method or not at run time, but we must check
# all local variable assignment, and that _will_ cost us.

e.g.

class Foo
  def pub
    foo = 2
  end

  private
  def foo=(x)
    p x
  end
end

Foo.new.pub

doesn't work. (also Dave's already showed in [ruby-talk:5412])

that means private methods end with `=' is useless. so I just assume
matz thought "if you can't use it as private method, make them public".

I just think this is more like document issue rather than anything
else.  

I was gonna vote for

c) leave it as private with warning when -w
   Warning: "private method ending with `=' will conflict with assignment"

with an entry for FAQ

Q: Why a private method like `foo=' doesn't work? how can I make it
work?

A: Because it conflict with local variable assgnment
statement. Running your script with switch `-w' gives you
warnning. You can do either, rename the method without `=' at the end,
or make it public.

but... once you know setters will always be public, I can live with
that without any problem.
--
         yashi