relation.rb in rom-3.2.2

- old
+ new

@@ -1,5 +1,7 @@
+require 'dry/core/class_attributes'
+
 require 'rom/initializer'
 require 'rom/relation/class_interface'
 
 require 'rom/pipeline'
 require 'rom/mapper_registry'
@@ -37,9 +39,16 @@
     # Default no-op output schema which is called in `Relation#each`
     NOOP_OUTPUT_SCHEMA = -> tuple { tuple }.freeze
 
     extend Initializer
     extend ClassInterface
+
+    extend Dry::Core::ClassAttributes
+    defines :schema_class, :schema_inferrer, :schema_dsl
+
+    schema_dsl Schema::DSL
+    schema_class Schema
+    schema_inferrer Schema::DEFAULT_INFERRER
 
     include Dry::Equalizer(:dataset)
     include Materializable
     include Pipeline
 