1 files changed, 62 insertions, 0 deletions
diff --git a/activemodel/lib/active_model/type/registry.rb b/activemodel/lib/active_model/type/registry.rb
new file mode 100644
index 0000000000..a19dc0f011
--- /dev/null
+++ b/activemodel/lib/active_model/type/registry.rb
@@ -0,0 +1,62 @@
+# frozen_string_literal: true
+
+module ActiveModel
+  # :stopdoc:
+  module Type
+    class Registry
+      def initialize
+        @registrations = []
+      end
+
+      def register(type_name, klass = nil, **options, &block)
+        block ||= proc { |_, *args| klass.new(*args) }
+        registrations << registration_klass.new(type_name, block, **options)
+      end
+
+      def lookup(symbol, *args)
+        registration = find_registration(symbol, *args)
+
+        if registration
+          registration.call(self, symbol, *args)
+        else
+          raise ArgumentError, "Unknown type #{symbol.inspect}"
+        end
+      end
+
+      private
+        attr_reader :registrations
+
+        def registration_klass
+          Registration
+        end
+
+        def find_registration(symbol, *args)
+          registrations.find { |r| r.matches?(symbol, *args) }
+        end
+    end
+
+    class Registration
+      # Options must be taken because of https://bugs.ruby-lang.org/issues/10856
+      def initialize(name, block, **)
+        @name = name
+        @block = block
+      end
+
+      def call(_registry, *args, **kwargs)
+        if kwargs.any? # https://bugs.ruby-lang.org/issues/10856
+          block.call(*args, **kwargs)
+        else
+          block.call(*args)
+        end
+      end
+
+      def matches?(type_name, *args, **kwargs)
+        type_name == name
+      end
+
+      private
+        attr_reader :name, :block
+    end
+  end
+  # :startdoc:
+end