From: Rudolf Polzer <denshimeiru-sapmctacher@...>
Date: 2003-07-03T03:42:28+09:00
Subject: Re: Using & for arrays of objects

Scripsit ille �Robert Klemme� <bob.news@gmx.net>:
> "Joel VanderWerf" <vjoel@PATH.Berkeley.EDU> schrieb im Newsbeitrag news:3F013010.7030703@path.berkeley.edu...
> > def i_think
> >    assert i_am  # ;)
> > end
> 
> Hmmm...  assert verifies that i_am is true, but Descartes concluded that
> i_am must return true if i_think returns true.  IMHO it's more like
> 
> class Human
>   attr_accessor :thinks
>   def am; @thinks; end
> end
> 
> I = Human.new
> I.am
> I.thinks = true
> I.am
> 
> Note, that "I" is a constant which reflects our understanding of identity
> quite good.

Not really... that's not Ruby.

In Ruby it would look like:

class Beer
  def am?()
    is?()
  end
  def are?()
    is?()
  end
end
class Human < Beer
  def initialize()
    @thinking = false
  end
  def think!()
    @thinking = true
  end
  def drink!()
    @thinking = false
  end
  def thinking?()
    @thinking
  end
  def is?()
    return true if @thinking
    # ... other sufficient conditions for being ...
    # otherwise...
    false
  end
end
# BTW: it's a Be-er, that is, someone who *is*. No cervisia!

i = Human.new()
i.think!()
p i.am?()


-- 
class Heisenberg; def initialize(r, p) @r = r; @p = p; end; def r();
@p += 2 * rand() - 1; @r; end; def p(); @r += 2 * rand() - 1; @p; end;
end; o = Heisenberg.new(17, 42); puts "impulse: %g, position: %g" %
[o.p(), o.r()]; puts "impulse: %g, position: %g" % [o.p(), o.r()];