Merge pull request #355 from Shopify/at-type-visitor

Introduce Type::Visitor

lib/rbi.rb

@@ -31,6 +31,7 @@ class Error < StandardError
 require "rbi/rewriters/sort_nodes"
 require "rbi/parser"
 require "rbi/type_parser"
+require "rbi/type_visitor"
 require "rbi/printer"
 require "rbi/formatter"
 require "rbi/version"

lib/rbi/type_visitor.rb

@@ -0,0 +1,112 @@
+# typed: strict
+# frozen_string_literal: true
+
+module RBI
+  class Type
+    class Visitor
+      extend T::Sig
+
+      class Error < RBI::Error; end
+
+      sig { params(node: Type).void }
+      def visit(node)
+        case node
+        when Type::Simple
+          visit_simple(node)
+        when Type::Void
+          visit_void(node)
+        when Type::Boolean
+          visit_boolean(node)
+        when Type::Nilable
+          visit_nilable(node)
+        when Type::Untyped
+          visit_untyped(node)
+        when Type::Generic
+          visit_generic(node)
+        when Type::Anything
+          visit_anything(node)
+        when Type::NoReturn
+          visit_no_return(node)
+        when Type::SelfType
+          visit_self_type(node)
+        when Type::AttachedClass
+          visit_attached_class(node)
+        when Type::ClassOf
+          visit_class_of(node)
+        when Type::All
+          visit_all(node)
+        when Type::Any
+          visit_any(node)
+        when Type::Tuple
+          visit_tuple(node)
+        when Type::Shape
+          visit_shape(node)
+        when Type::Proc
+          visit_proc(node)
+        when Type::TypeParameter
+          visit_type_parameter(node)
+        when Type::Class
+          visit_class(node)
+        else
+          raise Error, "Unhandled node: #{node.class}"
+        end
+      end
+
+      private
+
+      sig { params(type: Type::All).void }
+      def visit_all(type); end
+
+      sig { params(type: Type::Any).void }
+      def visit_any(type); end
+
+      sig { params(type: Type::Anything).void }
+      def visit_anything(type); end
+
+      sig { params(type: Type::AttachedClass).void }
+      def visit_attached_class(type); end
+
+      sig { params(type: Type::Boolean).void }
+      def visit_boolean(type); end
+
+      sig { params(type: Type::Class).void }
+      def visit_class(type); end
+
+      sig { params(type: Type::ClassOf).void }
+      def visit_class_of(type); end
+
+      sig { params(type: Type::Generic).void }
+      def visit_generic(type); end
+
+      sig { params(type: Type::Nilable).void }
+      def visit_nilable(type); end
+
+      sig { params(type: Type::Simple).void }
+      def visit_simple(type); end
+
+      sig { params(type: Type::NoReturn).void }
+      def visit_no_return(type); end
+
+      sig { params(type: Type::Proc).void }
+      def visit_proc(type); end
+
+      sig { params(type: Type::SelfType).void }
+      def visit_self_type(type); end
+
+      sig { params(type: Type::Void).void }
+      def visit_void(type); end
+
+      sig { params(type: Type::Shape).void }
+      def visit_shape(type); end
+
+      sig { params(type: Type::Tuple).void }
+      def visit_tuple(type); end
+
+      sig { params(type: Type::TypeParameter).void }
+      def visit_type_parameter(type); end
+
+      sig { params(type: Type::Untyped).void }
+      def visit_untyped(type); end
+    end
+  end
+end