Refactor life cmd

cmd/life/main.go

@@ -22,20 +22,29 @@ var (
 )
 
 func main() {
+	flag.Parse()
+
 	var log = slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{
 		AddSource: true,
 		Level:     slog.LevelDebug,
 	}))
 
-	if err := run(log); err != nil {
+	// Setup the main context.
+	// The context cancels on SIGINT or SIGTERM.
+	ctx, stop := signal.NotifyContext(
+		context.Background(),
+		syscall.SIGINT,
+		syscall.SIGTERM,
+	)
+	defer stop()
+
+	if err := run(ctx, log); err != nil {
 		log.Error("failed", slog.Any("error", err))
 		os.Exit(1)
 	}
 }
 
-func run(log *slog.Logger) error {
+func run(ctx context.Context, log *slog.Logger) error {
-	// Parse flags.
-	flag.Parse()
 	if *height < 0 {
 		return fmt.Errorf("invalid height: %d", *height)
 	}
@@ -46,10 +55,6 @@ func run(log *slog.Logger) error {
 		return fmt.Errorf("invalid tick: %d", *tick)
 	}
 
-	// Setup the main context.
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
 	// Setup workspace and log file.
 	cdir, err := os.UserCacheDir()
 	if err != nil {
@@ -92,18 +97,6 @@ func run(log *slog.Logger) error {
 		width = &cols
 	}
 
-	// TODO: refactor; handle sigwinch.
-	go func() {
-		var signals = make(chan os.Signal, 1)
-		signal.Notify(signals, syscall.SIGTERM, syscall.SIGINT)
-
-		// Block until we receive a signal.
-		s := <-signals
-		log.Debug("received signal", slog.Any("signal", s))
-
-		cancel()
-	}()
-
 	// Setup the game.
 	var game = life.New(life.Parameters{
 		Height:   *height,

internal/life/life.go

@@ -120,6 +120,7 @@ func (l *Life) Run(ctx context.Context) error {
 	}()
 
 	// Main loop.
+	// TODO: handle sigwinch; resize the world on terminal resize.
 	for {
 		select {
 		case <-ctx.Done():