Add ability to customize level values

globals.go

@@ -27,7 +27,22 @@ var (
 	// LevelFieldName is the field name used for the level field.
 	LevelFieldName = "level"
 
-	// LevelFieldMarshalFunc allows customization of global level field marshaling
+	// LevelTraceValue is the value used for the trace level field.
+	LevelTraceValue = "trace"
+	// LevelDebugValue is the value used for the debug level field.
+	LevelDebugValue = "debug"
+	// LevelInfoValue is the value used for the info level field.
+	LevelInfoValue = "info"
+	// LevelWarnValue is the value used for the warn level field.
+	LevelWarnValue = "warn"
+	// LevelErrorValue is the value used for the error level field.
+	LevelErrorValue = "error"
+	// LevelFatalValue is the value used for the fatal level field.
+	LevelFatalValue = "fatal"
+	// LevelPanicValue is the value used for the panic level field.
+	LevelPanicValue = "panic"
+
+	// LevelFieldMarshalFunc allows customization of global level field marshaling.
 	LevelFieldMarshalFunc = func(l Level) string {
 		return l.String()
 	}

log.go

@@ -134,19 +134,19 @@ const (
 func (l Level) String() string {
 	switch l {
 	case TraceLevel:
-		return "trace"
+		return LevelTraceValue
 	case DebugLevel:
-		return "debug"
+		return LevelDebugValue
 	case InfoLevel:
-		return "info"
+		return LevelInfoValue
 	case WarnLevel:
-		return "warn"
+		return LevelWarnValue
 	case ErrorLevel:
-		return "error"
+		return LevelErrorValue
 	case FatalLevel:
-		return "fatal"
+		return LevelFatalValue
 	case PanicLevel:
-		return "panic"
+		return LevelPanicValue
 	case Disabled:
 		return "disabled"
 	case NoLevel: