Achieving log.Lshortfile with the new slog package

slog_shortfile.go

// https://pkg.go.dev/golang.org/x/exp/slog

func main() {
	options := slog.HandlerOptions{
		AddSource: true,
		ReplaceAttr: func(a slog.Attr) slog.Attr {
			if a.Key != "source" {
				return a
			}
			fields := strings.Split(a.Value.String(), ":")
			path := filepath.Base(fields[0])
			return slog.String("source", path+":"+fields[1])
		},
	}
	slog.SetDefault(slog.New(options.NewTextHandler(os.Stderr)))
	// ...
}