From: "Berger, Daniel" <Daniel.Berger@...>
Date: 2006-02-03T00:39:28+09:00
Subject: Re: ruby-dev summary 28206-28273

> -----Original Message-----
> From: Martin DeMello [mailto:martindemello@yahoo.com] 
> Sent: Thursday, February 02, 2006 7:43 AM
> To: ruby-talk ML
> Subject: Re: ruby-dev summary 28206-28273
> 
> 
> Minero Aoki <aamine@loveruby.net> wrote:
> > 
> > [ruby-dev:28217] ANDCALL operator
> > 
> >   Nobuyoshi Nakada suggested a new operator `&?' (this 
> notation is temporary)
> >   which evaluates left-hand-side expression, and if it is 
> true then call
> >   right-hand-side method.  For example:
> > 
> >     if a[1] and a[1].strip.empty?
> >                 ||
> >     if a[1] &? strip.empty?
> > 
> >     h["key"] and h["key"].dispatch
> >                 ||
> >     h["key"] &? dispatch
> > 
> >   The motivation of this operator is to avoid duplication of 
> > expression.
> > 
> >   Takaaki Tateishi proposed another idea, Object#nil? with block
> >   (again, this name is temporary).
> > 
> >     a[1].nil? {|str| str.strip.empty? }
> >     h["key"].nil? {|h| h.dispatch }
> > 
> >   This issue is still open.

Yuck.  Looks like a hack from Perl6.  Not Ruby-ish.
 
> Syntactically, a method might look better than an operator:
> 
> a[1].if?.strip.empty?
> a[1].maybe.strip.empty?
> a[1].and.strip.empty?
> 
> martin

Looks better syntactically, but still has problems as Austin pointed
out.

I'd sooner accept "iff" (if and only if):

iff h["key"].dispatch -> same as: h["key"].dispatch if h["key"]

But, the idea of adding new keywords doesn't thrill me and I worry that
it's too terse.

Regards,

Dan