Function Repl

internal/repl/repl.go:90–224

(ctx context.Context, h *graph.Handle, queryLanguage string, timeout time.Duration)

)

func Repl(ctx context.Context, h *graph.Handle, queryLanguage string, timeout time.Duration) error {
	if queryLanguage == "" {
		queryLanguage = defaultLanguage
	}
	l := query.GetLanguage(queryLanguage)
	if l == nil || l.REPL == nil {
		return fmt.Errorf("unsupported query language: %q", queryLanguage)
	}
	ses := l.REPL(h.QuadStore)

	term, err := terminal(history)
	if os.IsNotExist(err) {
		fmt.Printf("creating new history file: %q\n", history)
	}
	defer persist(term, history)

	var (
		prompt = ps1

		code string
	)

	newCtx := func() (context.Context, func()) { return ctx, func() {} }
	if timeout > 0 {
		newCtx = func() (context.Context, func()) { return context.WithTimeout(ctx, timeout) }
	}

	for {
		select {
		case <-ctx.Done():
			return ctx.Err()
		default:
		}
		if len(code) == 0 {
			prompt = ps1
		} else {
			prompt = ps2
		}
		line, err := term.Prompt(prompt)
		if err != nil {
			if err == io.EOF {
				fmt.Println()
				return nil
			}
			return err
		}

		term.AppendHistory(line)

		line = strings.TrimSpace(line)
		if len(line) == 0 || line[0] == '#' {
			continue
		}

		if code == "" {
			cmd, args := splitLine(line)

			switch cmd {