1 files changed, 28 insertions, 3 deletions
diff --git a/pkg/server/automap.go b/pkg/server/automap.go
index 15cafe4..cf4de7d 100644
--- a/pkg/server/automap.go
+++ b/pkg/server/automap.go
@@ -1,12 +1,37 @@
 package server
 
-type automap map[int]interface{}
+import (
+	"errors"
+	"fmt"
+)
 
-func (m automap) add(v interface{}) int {
-	for k := 0;; k++ {
+type automap map[string]interface{}
+
+var errExists = errors.New("already exists")
+var errNotFound = errors.New("no such entry")
+
+func (m automap) add(v interface{}) string {
+	for n := 1;; n++ {
+		k := fmt.Sprintf("%d", n)
 		if _, ok := m[k]; !ok {
 			m[k] = v
 			return k
 		}
 	}
 }
+
+func (m automap) rename(old string, new string) (interface{}, error) {
+	if _, ok := m[old]; !ok {
+		return nil, errNotFound
+	}
+
+	if _, ok := m[new]; ok {
+		return nil, errExists
+	}
+
+	v := m[old]
+	m[new] = v
+
+	delete(m, old)
+	return v, nil
+}