irb.rb

LazyStruct.new({:a=>1, :b => 2}).a # => 2

# That's wrong. Why?

lazy_struct.rb

require 'lazy'
class LazyStruct < OpenStruct
	def self.to_self(value, key)
		klass = key.classify.constantize rescue self

		case value.class
		when Array
			value.map{|e| klass.new(e)}
		when Hash
			klass.new(value)
		else
			value
		end
	end

	def initialize(obj)
		@table = {}
		obj = (obj.respond_to? :each) ? obj : {'data' => obj}
		for k,v in obj
			@table[k.to_sym] = Lazy::Promise.new {self.class.to_self(v, k)}
			new_ostruct_member(k)
		end
	end

	def new_ostruct_member(name)
		name = name.to_sym
		unless self.respond_to?(name)
			class << self; self; end.class_eval do
				define_method(name) { @table[name].__result__ }
				define_method("#{name}=") { |x| modifiable[name] = x }
			end
		end
		name
	end
end