From: Kirk Haines <khaines@...>
Date: 2005-08-08T04:30:34+09:00
Subject: Re: Adding yet another Array.new form

On Sunday 07 August 2005 10:50 am, David A. Black wrote:

> >> def a
> >>   returning ary = [] do
> >>     ... construct ary by adding elements to it ...
> >>   end
> >> end
>
> [...]
>
> > I'd rather vote in favor of including #returning to the Ruby core.
> > It is a very helpful method to DRY.
>
> It feels a bit side-effect-dependent-ish, as written.  It might be
> nicer with a more traditional yield/block param syntax:
>
>    returning [] do |ary| ... end
>
> That shows more of the separation between the fact that you're
> returning an array, and the fact that you're assigning the name ary to
> that array for use inside the block.

It should work either way.  I haven't looked at the one in Rails, but mine:

module Kernel
        def returning(*vals)
                yield *vals
        end
end


def a
  returning tmp = [] do
    tmp << 1; tmp << 2; tmp << 3
  end
end

def b
  returning [] do |ary|
    ary << 1; ary << 2; ary << 3
  end
end

irb(main):013:0> a
=> [1, 2, 3]
irb(main):014:0> b
=> [1, 2, 3]
 
And I agree with you.  I like how the usage shown in b looks, myself, at least 
in the places where I use this construction.


Kirk Haines