func buildFmter(logger *streamlog.StreamLogger) func(url.Values, interface{}) string {
type formatter interface {
Format(url.Values) string
}
return func(params url.Values, val interface{}) string {
fmter, ok := val.(formatter)
if !ok {
return fmt.Sprintf("Error: unexpected value of type %T in %s!", val, logger.Name())
}
return fmter.Format(params)
}
}
