code ready for selective routing

app/router/router.go

@@ -12,7 +12,7 @@ var (
 )
 
 type Router interface {
-	TakeDetour(v2net.Destination) (*config.DetourTag, error)
+	TakeDetour(v2net.Destination) (config.DetourTag, error)
 }
 
 type RouterFactory interface {

app/router/rules/config/json/rules.go

@@ -10,9 +10,8 @@ type Rule struct {
 	OutboundTag string `json:"outboundTag"`
 }
 
-func (this *Rule) Tag() *config.DetourTag {
-	detourTag := config.DetourTag(this.OutboundTag)
-	return &detourTag
+func (this *Rule) Tag() config.DetourTag {
+	return config.DetourTag(this.OutboundTag)
 }
 
 func (this *Rule) Apply(dest v2net.Destination) bool {

app/router/rules/config/rules.go

@@ -6,6 +6,6 @@ import (
 )
 
 type Rule interface {
-	Tag() *config.DetourTag
+	Tag() config.DetourTag
 	Apply(dest v2net.Destination) bool
 }

app/router/rules/router.go

@@ -11,21 +11,23 @@ import (
 )
 
 var (
-	InvalidRule = errors.New("Invalid Rule")
-	EmptyTag    = pointconfig.DetourTag("")
+	InvalidRule      = errors.New("Invalid Rule")
+	NoRuleApplicable = errors.New("No rule applicable")
+
+	EmptyTag = pointconfig.DetourTag("")
 )
 
 type Router struct {
 	rules []config.Rule
 }
 
-func (this *Router) TakeDetour(dest v2net.Destination) (*pointconfig.DetourTag, error) {
+func (this *Router) TakeDetour(dest v2net.Destination) (pointconfig.DetourTag, error) {
 	for _, rule := range this.rules {
 		if rule.Apply(dest) {
 			return rule.Tag(), nil
 		}
 	}
-	return &EmptyTag, nil
+	return EmptyTag, NoRuleApplicable
 }
 
 type RouterFactory struct {