semantic: add forked reflect based DeepEqual

semantic/deep_equal.go

@@ -0,0 +1,30 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package semantic
+
+import (
+	"k8s.io/utils/third_party/forked/golang/reflect"
+)
+
+// Equalities is a map from type to a function comparing two values of
+// that type.
+type Equalities = reflect.Equalities
+
+// EqualitiesOrDie adds the given funcs and panics on any error.
+func EqualitiesOrDie(funcs ...interface{}) Equalities {
+	return reflect.EqualitiesOrDie(funcs...)
+}

third_party/forked/golang/reflect/README.md

@@ -0,0 +1,6 @@
+This was originally forked from https://github.com/golang/go/blob/master/src/reflect/deepequal.go in order to
+
+- consider empty lists and empty maps equal to their nil counterparts
+- add a `AddFuncs` mechanism to add custom equality funcs for specific types. 
+
+Meanwhile it has diverged quite a lot while still following the original algorithm at the core though.