Add Modify() and GetItem() to interface and badger store

main.go

@@ -8,7 +8,12 @@ type Store interface {
 	Set(key string, val interface{}) error
 	// Get places a value at a key into val
 	Get(key string, val interface{}) error
-	Delete(key string) error
+	// GetItem gets an item from the store
+	GetItem(string) (*Item, error)
+	// Delete deletes a value from the store
+	Delete(string) error
+	// Modify allows editing of a value in the store
+	Modify(string, ModifyFunc) error
 	// Bucket returns a bucket with the specified name
 	Bucket(name string) Bucket
 	// Iter returns an iterator
@@ -23,11 +28,18 @@ type Bucket interface {
 	Set(string, interface{}) error
 	// Get places a value at a key in the bucket into val
 	Get(string, interface{}) error
+	// GetItem gets an item from the store
+	GetItem(string) (*Item, error)
+	// Delete deletes a value from the bucket
 	Delete(key string) error
+	// Modify allows editing of a value in the bucket
+	Modify(string, ModifyFunc) error
 	// Iter returns an iterator for the bucket
 	Iter() Iter
 }
 
+type ModifyFunc func(*Item) (interface{}, error)
+
 // Item represents an iterator item
 type Item struct {
 	Key  string