From: "Florian Groß" <florgro@...>
Date: 2005-11-07T11:01:26+09:00
Subject: Re: Lazy fun: Make unary minus silence stderr for backticks

Sam Stephenson wrote:

> I was reading about mentalguy's lazy.rb and thought it'd be fun to use
> lazy evaluation as a vehicle for adding new syntactic sugar to Ruby. 
> Here's one such example, which lets you prefix backticks with a unary
> minus to silence stderr:
> 
> | % irb -r lazy_backtick
> | irb(main):001:0> `hello`
> | /opt/local/lib/ruby/1.8/irb/workspace.rb:81: command not found: hello
> | => ""
> | irb(main):002:0> -`hello`
> | => ""

Nice hack, but here's a case that doesn't work and for that I don't have 
a fix:

String.new(`echo foo`)

Which returns "" for me.

I guess you are better off not inheriting from String and letting the 
String === test fail. Nowadays it's all about duck typing, anyway.