Function simple_parser_main

Tools/peg_generator/pegen/parser.py:297–366

(parser_class: type[Parser])

def simple_parser_main(parser_class: type[Parser]) -> None:
    argparser = argparse.ArgumentParser()
    argparser.add_argument(
        "-v",
        "--verbose",
        action="count",
        default=0,
        help="Print timing stats; repeat for more debug output",
    )
    argparser.add_argument(
        "-q", "--quiet", action="store_true", help="Don't print the parsed program"
    )
    argparser.add_argument("filename", help="Input file ('-' to use stdin)")

    args = argparser.parse_args()
    verbose = args.verbose
    verbose_tokenizer = verbose >= 3
    verbose_parser = verbose == 2 or verbose >= 4

    t0 = time.time()

    filename = args.filename
    if filename == "" or filename == "-":
        filename = "<stdin>"
        file = sys.stdin
    else:
        file = open(args.filename)
    try:
        tokengen = tokenize.generate_tokens(file.readline)
        tokenizer = Tokenizer(tokengen, verbose=verbose_tokenizer)
        parser = parser_class(tokenizer, verbose=verbose_parser)
        tree = parser.start()
        try:
            if file.isatty():
                endpos = 0
            else:
                endpos = file.tell()
        except OSError:
            endpos = 0
    finally:
        if file is not sys.stdin:
            file.close()

    t1 = time.time()

    if not tree:
        err = parser.make_syntax_error(filename)
        traceback.print_exception(err.__class__, err, None)
        sys.exit(1)

    if not args.quiet:
        print(tree)

    if verbose:
        dt = t1 - t0
        diag = tokenizer.diagnose()
        nlines = diag.end[0]
        if diag.type == token.ENDMARKER: