Method ReadNumeral

LuaParser/src/Lexer/LuaLexer.cpp:427–458

LUA_NUMBER */ ** This function is quite liberal in what it accepts, as 'luaO_str2num' ** will reject ill-formed numerals. Roughly, it accepts the following ** pattern: ** ** %d(%x|%.|([Ee][+-]?))* | 0[Xx](%x|%.|([Pp][+-]?))* ** ** The only tricky part is to accept [+-] only after a valid exponent ** mark, to avoid reading '3-4' or '0xe+1' as a single number. ** ** The caller might have already r

** The caller might have already read an initial dot.
*/
LuaTokenKind LuaLexer::ReadNumeral() {
    int first = _reader.GetCurrentChar();
    const char *expo = "Ee";
    _reader.SaveAndNext();

    if (first == '0' && _reader.CheckNext2("xX")) /* hexadecimal? */
    {
        expo = "Pp";
    }

    for (;;) {
        if (_reader.CheckNext2(expo)) /* exponent mark? */
        {
            _reader.CheckNext2("-+");                                                      /* optional exponent sign */
        } else if (lisxdigit(_reader.GetCurrentChar()) || _reader.GetCurrentChar() == '.') /* '%x|%.' */
        {
            _reader.SaveAndNext();
        } else {
            break;
        }
    }

    // fix bug:这里不能使用lislalpha,否则会错误的解析下一个unicode字符
    if (std::isalpha(_reader.GetCurrentChar())) /* is numeral touching a letter? */
    {
        do {
            _reader.SaveAndNext();
        } while (std::isalpha(_reader.GetCurrentChar()));
    }

    return TK_NUMBER;
}

/*
** read a sequence '[=*[' or ']=*]', leaving the last bracket. If