module Yema
  module Validations

    def self.included(base)
      super
      base.extend(ClassMethods)
    end

    def valid?
      errors.empty?
    end

    def rules
      self.class.rules
    end

    def errors
      Set.new.tap do |errors|
        rules.each { |rule| errors.merge(rule.errors(self)) }
      end
    end

    module ClassMethods
      def rules
        @rules ||= Registry::Rule.new
      end
    end

  end
end