From: Rajinder Yadav <devguy.ca@...>
Date: 2009-10-13T08:47:58+09:00
Subject: Re: Enumerating and mixin.

Rajinder Yadav wrote:
> I am trying to learn the correct way to enumerate in Ruby, a few things 
> are missing in my 1st stab at this. How do I use mixin with Enumerable 
> to rewrite the class I have below? I can't seem to find a concrete 
> example online?
> 
> I know I am also missing code to override <=> if I wanted to do sorting, 
> are the other overrides I am missing?
> 
> How do I make my code more elegant, Thanks!
> 
> 
> class Vowels
>    def initialize
>       @index = 0
>       @list = %w(a e i o u)
>    end
> 
>    def each
>       while( @index < @list.size )
>          if @index >= @list.size
>             yield nil
>             exit
>          else
>             yield @list[@index]
>             @index += 1
>          end
>       end
>    end
> 
>    def first
>       @index=0
>    end
> end
> 
> obj = Vowels.new
> 
> obj.each { |x| puts x }
> 
> 
> 

OK I managed to sweet the code down to the following, is there anything else I 
missed?

class Vowels
    include Enumerable
    def initialize
       @list = %w(u e a o i)
    end

    def each
       @list.each { |item| yield item }
    end
end

obj = Vowels.new

obj.each { |s| print s }
puts ""
obj.sort.each { |s| print s }
puts ""


-- 
Kind Regards,
Rajinder Yadav

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