From: Brian Candler <b.candler@...>
Date: 2009-05-31T03:48:16+09:00
Subject: Re: Listing an Array created within a Class

Adrian Arlechin wrote:
> I am learning from Programming Ruby wich comes with Ruby instalation.
> In the chapter about containers - Implementing a SongList Container
> I took the code in NetBeans like follows:
> 
> require 'Baza.rb' #here is my Song class
> class SongList < Song
>   def initialize
>     @songs = Array.new
>   end
> end
> 
> class SongList
>   def append(aSong)
>     @songs.push(aSong)
>     self
>   end
> end
> 
> list = SongList.new
> list.
>   append(Song.new('title1', 'artist1', 1)).
>   append(Song.new('title2', 'artist2', 2)).
>   append(Song.new('title3', 'artist3', 3)).
>   append(Song.new('title4', 'artist4', 4))
> 
> ############# Here is my problem
> puts list.to_a ?????????

class SongList
  def to_a
    @songs
  end
end

puts list.to_a

OR:

class SongList
  attr_accessor :songs
end

puts list.songs

OR: another way is to make your SongList class duck-type like an Array

class SongList
  def [](elem)
    @songs[elem]
  end
  def []=(elem,obj)
    @songs[elem] = obj
  end
  # ... etc
end
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