From: dblack@...
Date: 2003-05-06T10:31:32+09:00
Subject: Re: Variable/Method ambiguity

Hi --

On Tue, 6 May 2003, Gennady wrote:

> Pickaxe p.212 explains the subject well enough, however here's an interesting case:
>
> class Test
>   def name=(name)
>     puts "Called 'name=' ..."
>   end
>   def test
>     name = "aaa"
>   end
> end
>
> Test.new.test
>
> I would expect to see "Called 'name=' ...", as Ruby can realize here
> that method "name=" is available and call it. However, nothing is
> printed, meaning that an assignment to local variable "name" took
> place.
>
> Is it only me who thinks that such behaviour is inconsistent?

I don't think it's inconsistent.  I think it would be inconsistent,
and confusing, if this:

  class A
    def thing=(x); end
    def other; thing = 100; end
  end

were different from this:

  class A
    def other; thing = 100; end
    def thing=(x); end
  end

or from this:

  class A
    def blah=(x); end
    def other; thing = 100; end
  end

As I understand it, the consistency is that, in all cases, the
receiver of a method must appear explicitly, unless both of these
things are true:
  (a) the receiver is self;
  (b) the variable could not be an already-defined local variable,
      or a local variable in the process of being defined.

I think this is the only algorithm that won't cause shifting behavior
in cases like the ones above.


David

-- 
David Alan Black
home: dblack@superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav