Clean up callback interfaces.

service/datastore/types.go

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+//go:generate stringer -type=Toggle
+
 package datastore
 
-import (
-        "fmt"
-)
-
 // GeoPoint represents a location as latitude/longitude in degrees.
 //
 // You probably shouldn't use these, but their inclusion here is so that the
 // datastore service can interact (and round-trip) correctly with other
 // datastore API implementations.
 type GeoPoint struct {
         Lat, Lng float64
 }
 
 // Valid returns whether a GeoPoint is within [-90, 90] latitude and [-180,
@@ skipping 21 matching lines @@
 // Toggle is a tri-state boolean (Auto/True/False), which allows structs
 // to control boolean flags for metadata in a non-ambiguous way.
 type Toggle byte
 
 // These are the allowed values for Toggle. Any other values are invalid.
 const (
         Auto Toggle = iota
         On
         Off
 )
-
-func (b Toggle) String() string {
-        switch b {
-        case Auto:
-                return "Auto"
-        case On:
-                return "On"
-        case Off:
-                return "Off"
-        default:
-                return fmt.Sprintf("UNKNOWN_Toggle(%d)", b)
-        }
-}