class Sass::Environment

def inherited_hash(name)
  class_eval <<RUBY, __FILE__, __LINE__ + 1
    def #{name}(name)
      @#{name}s[name] || @parent && @parent.#{name}(name)
    end
    def set_#{name}(name, value)
      @#{name}s[name] = value unless try_set_#{name}(name, value)
    end
    def try_set_#{name}(name, value)
      if @#{name}s.include?(name)
        @#{name}s[name] = value
        true
      elsif @parent
        @parent.try_set_#{name}(name, value)
      else
        false
      end
    end
    protected :try_set_#{name}
    def set_local_#{name}(name, value)
      @#{name}s[name] = value
    end
end