From: Stefan Lang <perfectly.normal.hacker@...>
Date: 2008-03-10T08:02:22+09:00
Subject: Re: passing procs around in variables

2008/3/9, Nathan <njmacinnes@gmail.com>:
> [...]
>  Now, the Item class, which each menu item is an object of, doesn't
>  work as expected... take a look here: http://pastie.caboo.se/163781.
>  When I try to call myItem.execute!, it complains "no block given". If
>  I call myItem.execute! { 2 + 1}, then it works, but that's not what I
>  want...

>  class Item
>    attr_reader :text
>
>    def initialize(description, &proc)
>      @description = description
>      @proc = proc
>    end
>
>    def execute!
>      yield @proc
>    end
>  end

Use yield when the block is _not_ stored in a variable.
What your yield line does is this: Call the block given to
execute! with @proc as argument.

Once you have a proc object, you can call it, well, with
the "call" method. Just change "yield @proc" to
"@proc.call" and it should work.

HTH,
  Stefan