value.rb

        def node(input, *args)
          if input.is_a?(::Symbol)
            [type, [name, predicate(input, *args).to_ast]]
          elsif input.respond_to?(:rule)
            [type, [name, [:type, input]]]
          elsif input.is_a?(::Class) && input < ::Dry::Struct
            [type, [name, [:schema, Schema.create_class(self, input)]]]
          elsif input.is_a?(Schema)
            [type, [name, schema(input).to_ast]]
          else
            [type, [name, input.to_ast]]
          end
        end