From: surf <surfunbear@...>
Date: 2006-08-26T15:10:10+09:00
Subject: Re: A use case for an ordered hash


Hal Fulton wrote:
> surf wrote:
> >
> >  Can't you create your own using mixins and including enumerable or
> > something like that ?
> >
>
> Yes, but I would lose the convenient literal notation.
>
> Hal


 I was curious about this, so I had to try it:

================================================

class OrderedHash

include Enumerable


def initialize(*parm)
 @arr = parm
 @hash = {}
 parm.each do |p|
   p.each do |k,v|
     @hash[k] = v
   end
 end
end

def []=(idx, val)
 el = {idx => val}
 @arr << el
 @hash[idx] = val
end

def [](idx)
 @hash[idx]
end

def each
  @arr.each do |e|
    e.each do |k,v|
      yield k,v
    end
  end
end

end


# need each paramter in {}, could also work out a way to do
# [:frog,"green", :sky, "blue" etc ]

thingColor = OrderedHash.new({:frog => "green"},
                             {:sky => "blue"},
                             {:elephant => "pink"},
                             {:scarf => "red"}

                    )

puts "the sky is #{thingColor[:sky]}\n\n"

thingColor[:limo] = "black"
thingColor[:snowman] = "white"


thingColor.each do |k,v|
  puts "#{k} = #{v}"
end