From: "Martin J. Dürst" <duerst@...>
Date: 2010-09-09T20:33:58+09:00
Subject: [ruby-core:32222] Re: Ruby 2.0 Wiki/Wish-list?

On 2010/09/09 3:50, Kurt Stephens wrote:

> ---------------------------------------------------
>
> I'd like to implement:
>
> x // y # and x //= y
>
> =>
>
> (tmp = x) != nil ? tmp : y

One case that I remember having met frequently, and that seems to be 
related to this, is:
In a method chain, apply methods successively, except if the receiver is 
  nil, in which case, just keep it as nil.

As an example, I'd like to write something like:

((tmp1=a).nil? ? nil : tmp1.method1(args))

as something like:

a.unless_nil.method1(args)


> And
>
> x&&.y&&.z # and x//.y//.z
>
> =>
>
> (tmp = x) && (tmp = tmp.y) && tmp.z

Shouldn't that be
(tmp = x) && tmp.y && tmp.z ? That would make more sense to me. Also, is 
there a way to express this as a binary operator?

And what's the semantics of x//.y//.z ?

Regards,    Martin.


-- 
#-# Martin J. D��rst, Professor, Aoyama Gakuin University
#-# http://www.sw.it.aoyama.ac.jp   mailto:duerst@it.aoyama.ac.jp