なにかの断片 - OrderdHash

orderdhash.rb

class OrderdHash
	extend  Forwardable
	extend  Container
	include Enumerable
	
	def initialize(keys=[], content={})
		@keys, @content = keys, content
	end
	
	def_delegator :@keys, :each, :each_key
	def_delegator :@keys, :dup, :keys
	def_delegators :@content, :[], :has_key?
	
	def each_pair
		@keys.each{|key|yield key, @content[key]}
	end
	
	def each_value
		each_key{|key|yield @content[key]}
	end
	
	alias_method :each, :each_pair
	
	def []=(key, value)
		@keys << key unless @keys.include? key
		@content[key] = value
	end
	
	def values
		map{|key, value|value}
	end
	
	def hash
		[@keys, @content].hash
	end
	
	def ==(other)
		hash == other.hash
	end

	def select
		raise ArgumentError unless block_given?
		
		keys    = []
		content = {}
		
		each_pair do |key, value|
			if yield key, value
				keys << key
				content[key] = value
			end
		end
		
		self.class.new keys, content
	end
end