mjacobus / koine-attributes

      class Base

        def coerce(*_values)

          raise NotImplementedError

        end

        def default_value

          @default_value.respond_to?(:call) &&

            @default_value.call ||

            @default_value

        end

        def with_default_value(value = nil, &block)

          @default_value = value

          @default_value = block if block

          self

        end

        protected

        # duplicates if possible and freezes object

        def secure

          value = yield

          value = value.dup if value.respond_to?(:dup)

          value.freeze

        end

      end