code style simplify

@@ -51,7 +51,7 @@ func Register(name string, adapter Cache) {
 	if adapter == nil {
 	if adapter == nil {
 		panic("cache: Register adapter is nil")
 		panic("cache: Register adapter is nil")
 	}
 	}
-	if _, dup := adapters[name]; dup {
+	if _, ok := adapters[name]; ok {
 		panic("cache: Register called twice for adapter " + name)
 		panic("cache: Register called twice for adapter " + name)
 	}
 	}
 	adapters[name] = adapter
 	adapters[name] = adapter
@@ -60,14 +60,15 @@ func Register(name string, adapter Cache) {
 // Create a new cache driver by adapter name and config string.
 // Create a new cache driver by adapter name and config string.
 // config need to be correct JSON as string: {"interval":360}.
 // config need to be correct JSON as string: {"interval":360}.
 // it will start gc automatically.
 // it will start gc automatically.
-func NewCache(adapterName, config string) (Cache, error) {
+func NewCache(adapterName, config string) (adapter Cache, e error) {
 	adapter, ok := adapters[adapterName]
 	adapter, ok := adapters[adapterName]
 	if !ok {
 	if !ok {
-		return nil, fmt.Errorf("cache: unknown adapter name %q (forgot to import?)", adapterName)
+		e = fmt.Errorf("cache: unknown adapter name %q (forgot to import?)", adapterName)
+		return
 	}
 	}
 	err := adapter.StartAndGC(config)
 	err := adapter.StartAndGC(config)
 	if err != nil {
 	if err != nil {
-		return nil, err
+		adapter = nil
 	}
 	}
-	return adapter, nil
+	return
 }
 }

@@ -22,12 +22,11 @@ func GetString(v interface{}) string {
 	case []byte:
 	case []byte:
 		return string(result)
 		return string(result)
 	default:
 	default:
-		if v == nil {
-			return ""
-		} else {
+		if v != nil {
 			return fmt.Sprintf("%v", result)
 			return fmt.Sprintf("%v", result)
 		}
 		}
 	}
 	}
+	return ""
 }
 }
 
 
 // convert interface to int.
 // convert interface to int.
@@ -40,14 +39,11 @@ func GetInt(v interface{}) int {
 	case int64:
 	case int64:
 		return int(result)
 		return int(result)
 	default:
 	default:
-		d := GetString(v)
-		if d != "" {
-			value, err := strconv.Atoi(d)
-			if err == nil {
+		if d := GetString(v); d != "" {
+			value, _ := strconv.Atoi(d)
 			return value
 			return value
 		}
 		}
 	}
 	}
-	}
 	return 0
 	return 0
 }
 }
 
 
@@ -61,12 +57,10 @@ func GetInt64(v interface{}) int64 {
 	case int64:
 	case int64:
 		return result
 		return result
 	default:
 	default:
-		d := GetString(v)
-		if d != "" {
-			result, err := strconv.ParseInt(d, 10, 64)
-			if err == nil {
-				return result
-			}
+
+		if d := GetString(v); d != "" {
+			value, _ := strconv.ParseInt(d, 10, 64)
+			return value
 		}
 		}
 	}
 	}
 	return 0
 	return 0
@@ -78,14 +72,11 @@ func GetFloat64(v interface{}) float64 {
 	case float64:
 	case float64:
 		return result
 		return result
 	default:
 	default:
-		d := GetString(v)
-		if d != "" {
-			value, err := strconv.ParseFloat(d, 64)
-			if err == nil {
+		if d := GetString(v); d != "" {
+			value, _ := strconv.ParseFloat(d, 64)
 			return value
 			return value
 		}
 		}
 	}
 	}
-	}
 	return 0
 	return 0
 }
 }
 
 
@@ -95,12 +86,9 @@ func GetBool(v interface{}) bool {
 	case bool:
 	case bool:
 		return result
 		return result
 	default:
 	default:
-		d := GetString(v)
-		if d != "" {
-			result, err := strconv.ParseBool(d)
-			if err == nil {
-				return result
-			}
+		if d := GetString(v); d != "" {
+			value, _ := strconv.ParseBool(d)
+			return value
 		}
 		}
 	}
 	}
 	return false
 	return false