From: Chris Gehlker <canyonrat@...>
Date: 2006-08-13T04:21:15+09:00
Subject: Pickaxe Question

On page 53 of the Pickaxe Book there is a little example illustrating  
Proc parameters:

songlist = SongList.new
class JukeboxButton < Button
        def initialize(label, &action)
            super(label)
            @action = action
          end
       def button_pressed
            @action.call(self)
       end
end
start_button = JukeboxButton.new("Start") { songlist.start }
pause_button = JukeboxButton.new("Pause") { songlist.pause }

If I understand this example correctly, we are supposed to assume  
that the
mapping of the instances of JukeboxButton to actual hardware buttons  
happens, by magic, when we call the button initializer and pass it  
the appropriate string with the super(label) message. But if that's  
the case, I don't understand why button_pressed needs to pass self as  
an argument to the @action.call message. It seems like the  
songlist.start and songlist.pause methods just drop the argument.
--
A young idea is a beautiful and a fragile thing. Attack people, not  
ideas.