From: Eric Mahurin <eric_mahurin@...>
Date: 2005-08-19T00:36:56+09:00
Subject: Re: polymorphism and/or named parameters: the ruby way?

--- James Edward Gray II <james@grayproductions.net> wrote:

> On Aug 8, 2005, at 12:21 PM, Eric Mahurin wrote:
> 
> > --- "Berger, Daniel" <Daniel.Berger@qwest.com> wrote:
> >>
> >> A typical idiom for constructors is to do "yield self if
> >> block_given?",
> >> which I prefer over hash based arguments.  For example:
> >>
> >> class Foo
> >>    attr_accessor :bar, :baz, :zap
> >>    def initialize
> >>       yield self if block_given?
> >>    end
> >> end
> >>
> >> foo = Foo.new do |f|
> >>    f.bar = "hello"
> >>    f.baz = 5
> >>    f.zap = "world"
> >> end
> >>
> >
> > What's the advantage of this over:
> >
> > foo = Foo.new
> > foo.bar = "hello"
> > foo.baz = 5
> > foo.zap = "world"
> 
> Perhaps you want to create and use an object without even
> assigning  
> it to a variable:
> 
> Message do |mes|
>      # build message here...
> 
>      mes.send
> end

You missed a .new, I believe.

I'd still say my Object#post (someone else called it "then")
would be a better thing to have instead of every initialize
doing "yield self if block_given?" at the end.  If there was
something done after the yield (like checking or even
closing/destroying the object), then there'd be more use.

class Object
  def post
    yield(self)
    self
  end
end

Message.new.post do |mes|
     # build message here... 
     mes.send
end



		
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