From: Joel VanderWerf <vjoel@...>
Date: 2006-11-16T10:40:43+09:00
Subject: Re: #returning and #tap

Eric Hodel wrote:
...
> So... it usually doesn't save any lines, it adds typing, it hides the 
> object you're returning in the middle of a statement and it is 
> significantly more expensive to execute[1].  (Oh, but maybe, in some 
> cases, it might save you one or two lines of code.)
> 
> No thanks.
> 
> I don't think that makes it more rubyish.  Every time I've encountered 
> #returning in Rails I've found it decreased the readability of the code 
> and uselessly increased the complexity.  (Wait, now what does this 
> return? oh, yeah, way up there.)

This variant saves typing and IMO is more idiomatically ruby:

class Object
   def then
     yield(self)
     self
   end
end

def foo
   @foo ||= Foo.new.then do |f|
     f.bar = "bar"
   end
end


Otherwise you have to do this:

def foo
   unless @foo
     @foo = Foo.new
     @foo.bar = "bar"
   end
   @foo
end

-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407