qtextstream.cpp

奇趣公司比较新的qt/emd版本

        InputN = 6,
        InputF = 7,
        InputA = 8,
        InputT = 9
    };

    static uchar table[13][10] = {
        // None InputSign InputDigit InputDot InputExp InputI    InputN    InputF    InputA    InputT
        { 0,    Sign,     Mantissa,  Dot,     0,       Inf1,     Nan1,     0,        0,        0      }, // 0  Init
        { 0,    0,        Mantissa,  Dot,     0,       Inf1,     Nan1,     0,        0,        0      }, // 1  Sign
        { Done, Done,     Mantissa,  Dot,     ExpMark, 0,        0,        0,        0,        0      }, // 2  Mantissa
        { 0,    0,        Abscissa,  0,       0,       0,        0,        0,        0,        0      }, // 3  Dot
        { Done, Done,     Abscissa,  Done,    ExpMark, 0,        0,        0,        0,        0      }, // 4  Abscissa
        { 0,    ExpSign,  Exponent,  0,       0,       0,        0,        0,        0,        0      }, // 5  ExpMark
        { 0,    0,        Exponent,  0,       0,       0,        0,        0,        0,        0      }, // 6  ExpSign
        { Done, Done,     Exponent,  Done,    Done,    0,        0,        0,        0,        0      }, // 7  Exponent
        { 0,    0,        0,         0,       0,       0,        0,        0,        Nan2,     0      }, // 8  Nan1
        { 0,    0,        0,         0,       0,       0,        NanInf,   0,        0,        0      }, // 9  Nan2
        { 0,    0,        0,         0,       0,       0,        Inf2,     0,        0,        0      }, // 10 Inf1
        { 0,    0,        0,         0,       0,       0,        0,        NanInf,   0,        0      }, // 11 Inf2
        { Done, 0,        0,         0,       0,       0,        0,        0,        0,        0      }, // 11 NanInf
    };

    ParserState state = Init;
    InputToken input = None;

    scan(0, 0, 0, NotSpace);
    consumeLastToken();

    const int BufferSize = 128;
    char buf[BufferSize];
    int i = 0;

    QChar c;
    while (getChar(&c)) {
        switch (c.unicode()) {
        case '+':
        case '-':
            input = InputSign;
            break;
        case '0': case '1': case '2': case '3': case '4':
        case '5': case '6': case '7': case '8': case '9':
            input = InputDigit;
            break;
        case '.':
            input = InputDot;
            break;
        case 'e':
        case 'E':
            input = InputExp;
            break;
        case 'i': case 'I':
            input = InputI;
            break;
        case 'n': case 'N':
            input = InputN;
            break;
        case 'f': case 'F':
            input = InputF;
            break;
        case 'a': case 'A':
            input = InputA;
            break;
        case 't': case 'T':
            input = InputT;
            break;
        default:
            input = None;
            break;
        }

        state = ParserState(table[state][input]);

        if  (state == Init || state == Done || i > (BufferSize - 5)) {
            ungetChar(c);
            if (i > (BufferSize - 5)) { // ignore rest of digits
                while (getChar(&c)) {
                    if (!c.isDigit()) {
                        ungetChar(c);
                        break;
                    }
                }
            }
            break;
        }

        buf[i++] = c.toLatin1();
    }

    if (i == 0)
        return false;
    if (!f)
        return true;

    // ### Number parsing should really be handled by QLocale.
    char c0 = buf[0] | 32; // tolower
    char c1 = buf[1] | 32; // tolower
    bool sign = true;
    if (c0 == '+' || c0 == '-') {
        sign = (c0 == '+');
        c0 = c1;
    }
    if (c0 == 'i') {
        *f = sign ? qInf() : -qInf();
    } else if (c0 == 'n') {
        *f = qQNaN();
    } else {
        buf[i] = '\0';
        *f = strtod(buf, 0);
    }
    return true;
}

/*!
    Reads a character from the stream and stores it in \a c. Returns a
    reference to the QTextStream, so several operators can be
    nested. Example:

    \code
        QTextStream in(file);
        QChar ch1, ch2, ch3;
        in >> ch1 >> ch2 >> ch3;
    \endcode

    Whitespace is \e not skipped.
*/

QTextStream &QTextStream::operator>>(QChar &c)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->scan(0, 0, 0, QTextStreamPrivate::NotSpace);
    if (!d->getChar(&c))
        setStatus(ReadPastEnd);
    return *this;
}

/*!
    \overload

    Reads a character from the stream and stores it in \a c. The
    character from the stream is converted to ISO-5589-1 before it is
    stored.

    \sa QChar::toLatin1()
*/
QTextStream &QTextStream::operator>>(char &c)
{
    QChar ch;
    *this >> ch;
    c = ch.toLatin1();
    return *this;
}

/*!
    Reads an integer from the stream and stores it in \a i, then
    returns a reference to the QTextStream. The number is cast to
    the correct type before it is stored. If no number was detected on
    the stream, \a i is set to 0.

    By default, QTextStream will attempt to detect the base of the
    number using the following rules:

    \table
    \header \o Prefix                \o Base
    \row    \o "0b" or "0B"          \o 2 (binary)
    \row    \o "0" followed by "0-7" \o 8 (octal)
    \row    \o "0" otherwise         \o 10 (decimal)
    \row    \o "0x" or "0X"          \o 16 (hexadecimal)
    \row    \o "1" to "9"            \o 10 (decimal)
    \endtable

    By calling setIntegerBase(), you can specify the integer base
    explicitly. This will disable the auto-detection, and speed up
    QTextStream slightly.

    Leading whitespace is skipped.
*/
QTextStream &QTextStream::operator>>(signed short &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(signed short);
}

/*!
    \overload

    Stores the integer in the unsigned short \a i.
*/
QTextStream &QTextStream::operator>>(unsigned short &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(unsigned short);
}

/*!
    \overload

    Stores the integer in the signed int \a i.
*/
QTextStream &QTextStream::operator>>(signed int &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(signed int);
}

/*!
    \overload

    Stores the integer in the unsigned int \a i.
*/
QTextStream &QTextStream::operator>>(unsigned int &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(unsigned int);
}

/*!
    \overload

    Stores the integer in the signed long \a i.
*/
QTextStream &QTextStream::operator>>(signed long &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(signed long);
}

/*!
    \overload

    Stores the integer in the unsigned long \a i.
*/
QTextStream &QTextStream::operator>>(unsigned long &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(unsigned long);
}

/*!
    \overload

    Stores the integer in the qlonglong \a i.
*/
QTextStream &QTextStream::operator>>(qlonglong &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(qlonglong);
}

/*!
    \overload

    Stores the integer in the qulonglong \a i.
*/
QTextStream &QTextStream::operator>>(qulonglong &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(qulonglong);
}

/*!
    Reads a real number from the stream and stores it in \a f, then
    returns a reference to the QTextStream. The number is cast to
    the correct type. If no real number is detect on the stream, \a f
    is set to 0.0.

    As a special exception, QTextStream allows the strings "nan" and "inf" to
    represent NAN and INF floats or doubles.

    Leading whitespace is skipped.
*/
QTextStream &QTextStream::operator>>(float &f)
{
    IMPLEMENT_STREAM_RIGHT_REAL_OPERATOR(float);
}

/*!
    \overload

    Stores the real number in the double \a f.
*/
QTextStream &QTextStream::operator>>(double &f)
{
    IMPLEMENT_STREAM_RIGHT_REAL_OPERATOR(double);
}

/*!
    Reads a word from the stream and stores it in \a str, then returns
    a reference to the stream. Words are separated by whitespace
    (i.e., all characters for which QChar::isSpace() returns true).

    Leading whitespace is skipped.
*/
QTextStream &QTextStream::operator>>(QString &str)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);

    str.clear();
    d->scan(0, 0, 0, QTextStreamPrivate::NotSpace);
    d->consumeLastToken();

    const QChar *ptr;
    int length;
    if (!d->scan(&ptr, &length, 0, QTextStreamPrivate::Space)) {
        setStatus(ReadPastEnd);
        return *this;
    }

    str = QString(ptr, length);
    d->consumeLastToken();
    return *this;
}

/*!
    \overload

    Converts the word to ISO-8859-1, then stores it in \a array.

    \sa QString::toLatin1()
*/
QTextStream &QTextStream::operator>>(QByteArray &array)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);

    array.clear();
    d->scan(0, 0, 0, QTextStreamPrivate::NotSpace);
    d->consumeLastToken();

    const QChar *ptr;
    int length;
    if (!d->scan(&ptr, &length, 0, QTextStreamPrivate::Space)) {
        setStatus(ReadPastEnd);
        return *this;
    }

    for (int i = 0; i < length; ++i)
        array += ptr[i].toLatin1();

    d->consumeLastToken();
    return *this;
}

/*!
    \overload

    Stores the word in \a c, terminated by a '\0' character. If no word is
    available, only the '\0' character is stored.

    Warning: Although convenient, this operator is dangerous and must
    be used with care. QTextStream assumes that \a c points to a
    buffer with enough space to hold the word. If the buffer is too
    small, your application may crash.

    If possible, use the QByteArray operator instead.
*/
QTextStream &QTextStream::operator>>(char *c)
{
    Q_D(QTextStream);
    *c = 0;
    CHECK_VALID_STREAM(*this);
    d->scan(0, 0, 0, QTextStreamPrivate::NotSpace);
    d->consumeLastToken();

    const QChar *ptr;
    int length;
    if (!d->scan(&ptr, &length, 0, QTextStreamPrivate::Space)) {
        setStatus(ReadPastEnd);
        return *this;
    }

    for (int i = 0; i < length; ++i)
        *c++ = ptr[i].toLatin1();
    *c = '\0';
    d->consumeLastToken();
    return *this;
}

/*! \internal
 */
bool QTextStreamPrivate::putNumber(qulonglong number, bool negative)
{
    QString prefix;
    if (negative)
        prefix = QLatin1Char('-');
    else if (numberFlags & QTextStream::ForceSign)
        prefix = QLatin1Char('+');

    if (numberFlags & QTextStream::ShowBase) {
        switch (integerBase) {
        case 2: prefix += QLatin1String("0b"); break;
        case 8: prefix += QLatin1String("0"); break;
        case 16: prefix += QLatin1String("0x"); break;
        default: break;
        }
        if (numberFlags & QTextStream::UppercaseBase)
            prefix = prefix.toUpper(); // ### in-place instead
    }

    QString digits = QString::number(number, integerBase ? integerBase : 10);
    if (numberFlags & QTextStream::UppercaseDigits)
        digits = digits.toUpper(); // ### in-place instead

    return putString(prefix + digits);
}

/*!
    \internal
    \overload
*/
QTextStream &QTextStream::operator<<(QBool b)
{
    return *this << bool(b);
}

/*!
    Writes the character \a c to the stream, then returns a reference
    to the QTextStream.

    \sa setFieldWidth()
*/
QTextStream &QTextStream::operator<<(QChar c)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->putString(QString(c));
    return *this;
}

/*!
    \overload

    Converts \a c from ASCII to a QChar, then writes it to the stream.
*/
QTextStream &QTextStream::operator<<(char c)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->putString(QString(QChar::fromAscii(c)));
    return *this;
}

/*!
    Writes the integer number \a i to the stream, then returns a
    reference to the QTextStream. By default, the number is stored in
    decimal form, but you can also set the base by calling
    setIntegerBase().

    \sa setFieldWidth(), setNumberFlags()
*/
QTextStream &QTextStream::operator<<(signed short i)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->putNumber((qulonglong)qAbs(qlonglong(i)), i < 0);
    return *this;
}

/*!
    \overload

    Writes the unsigned short \a i to