Refactor VariableGen - no interface needed

staging/src/k8s.io/code-generator/cmd/validation-gen/validation.go

@@ -1211,21 +1211,20 @@ func (g *genValidations) emitValidationVariables(c *generator.Context, t *types.
 	tn := g.discovered.typeNodes[t]
 
 	variables := tn.typeValidations.Variables
-	slices.SortFunc(variables, func(a, b validators.VariableGen) int {
-		return cmp.Compare(a.Var().Name, b.Var().Name)
+	slices.SortFunc(variables, func(a, b *validators.VariableGen) int {
+		return cmp.Compare(a.Variable.Name, b.Variable.Name)
 	})
 	for _, variable := range variables {
-		fn := variable.Init()
+		fn := variable.InitFunc
 		targs := generator.Args{
-			"varName": c.Universe.Type(types.Name(variable.Var())),
+			"varName": c.Universe.Type(types.Name(variable.Variable)),
 			"initFn":  c.Universe.Type(fn.Function),
 		}
 		for _, comment := range fn.Comments {
 			sw.Do("// $.$\n", comment)
 		}
 		sw.Do("var $.varName|private$ = $.initFn|raw$", targs)
-		typeArgs := variable.Init().TypeArgs
-		if len(typeArgs) > 0 {
+		if typeArgs := fn.TypeArgs; len(typeArgs) > 0 {
 			sw.Do("[", nil)
 			for i, typeArg := range typeArgs {
 				sw.Do("$.|raw$", c.Universe.Type(typeArg))

staging/src/k8s.io/code-generator/cmd/validation-gen/validators/validators.go

@@ -232,7 +232,7 @@ type Validations struct {
 
 	// Variables holds any variables which must be generated to perform
 	// validation.  Variables are not permitted in every context.
-	Variables []VariableGen
+	Variables []*VariableGen
 
 	// Comments holds comments to emit (without the leanding "//").
 	Comments []string
@@ -263,7 +263,7 @@ func (v *Validations) AddFunction(f FunctionGen) {
 	v.Functions = append(v.Functions, f)
 }
 
-func (v *Validations) AddVariable(variable VariableGen) {
+func (v *Validations) AddVariable(variable *VariableGen) {
 	v.Variables = append(v.Variables, variable)
 }
 
@@ -325,20 +325,6 @@ type Identifier types.Name
 // PrivateVars are generated using the PrivateNamer strategy.
 type PrivateVar types.Name
 
-// VariableGen provides validation-gen with the information needed to generate variable.
-// Variables typically support generated functions by providing static information such
-// as the list of supported symbols for an enum.
-type VariableGen interface {
-	// TagName returns the tag which triggers this validator.
-	TagName() string
-
-	// Var returns the variable identifier.
-	Var() PrivateVar
-
-	// Init generates the function call that the variable is assigned to.
-	Init() FunctionGen
-}
-
 // Function creates a FunctionGen for a given function name and extraArgs.
 func Function(tagName string, flags FunctionFlags, function types.Name, extraArgs ...any) FunctionGen {
 	return FunctionGen{
@@ -405,28 +391,19 @@ func (fg FunctionGen) WithComment(comment string) FunctionGen {
 }
 
 // Variable creates a VariableGen for a given function name and extraArgs.
-func Variable(variable PrivateVar, init FunctionGen) VariableGen {
-	return &variableGen{
-		variable: variable,
-		init:     init,
+func Variable(variable PrivateVar, initFunc FunctionGen) *VariableGen {
+	return &VariableGen{
+		Variable: variable,
+		InitFunc: initFunc,
 	}
 }
 
-type variableGen struct {
-	variable PrivateVar
-	init     FunctionGen
-}
+type VariableGen struct {
+	// Variable holds the variable identifier.
+	Variable PrivateVar
 
-func (v variableGen) TagName() string {
-	return v.init.TagName
-}
-
-func (v variableGen) Var() PrivateVar {
-	return v.variable
-}
-
-func (v variableGen) Init() FunctionGen {
-	return v.init
+	// InitFunc describes the function call that the variable is assigned to.
+	InitFunc FunctionGen
 }
 
 // WrapperFunction describes a function literal which has the fingerprint of a