/****************************************************************************
**
** Copyright (C) 1992-2007 Trolltech ASA. All rights reserved.
**
** This file is part of the $MODULE$ of the Qt Toolkit.
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** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
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****************************************************************************/

#ifndef QSCRIPTLEXER_P_H
#define QSCRIPTLEXER_P_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include <QtCore/QString>

class QScriptEngine;
class QScriptEnginePrivate;
class QScriptNameIdImpl;

namespace QScript {

class Lexer
{
public:
    Lexer(QScriptEngine *eng);
    ~Lexer();

    void setCode(const QString &c, int lineno);
    int lex();

    int lineNo() const { return yylineno; }
    bool prevTerminator() const { return terminator; }

    enum State { Start,
                 Identifier,
                 InIdentifier,
                 InSingleLineComment,
                 InMultiLineComment,
                 InNum,
                 InNum0,
                 InHex,
                 InOctal,
                 InDecimal,
                 InExponentIndicator,
                 InExponent,
                 Hex,
                 Octal,
                 Number,
                 String,
                 Eof,
                 InString,
                 InEscapeSequence,
                 InHexEscape,
                 InUnicodeEscape,
                 Other,
                 Bad };

    bool scanRegExp();
    void scanExtraIdentifiers(bool scan)
        { extraIdentifiers = scan; }

    QScriptNameIdImpl *pattern;
    QScriptNameIdImpl *flags;

    State lexerState() const
        { return state; }

    QString errorMessage() const
        { return errmsg; }
    void setErrorMessage(const QString &err)
        { errmsg = err; }
    void setErrorMessage(const char *err)
        { setErrorMessage(QString::fromLatin1(err)); }

private:
    QScriptEnginePrivate *driver;
    int yylineno;
    bool done;
    char *buffer8;
    QChar *buffer16;
    uint size8, size16;
    uint pos8, pos16;
    bool terminator;
    bool restrKeyword;
    // treat "null", "false" and "true" as identifiers
    bool extraIdentifiers;
    // encountered delimiter like "'" and "}" on last run
    bool delimited;
    int stackToken;

    State state;
    void setDone(State s);
    uint pos;
    void shift(uint p);
    int lookupKeyword(const char *);

    bool isWhiteSpace() const;
    bool isLineTerminator() const;
    bool isHexDigit(ushort c) const;
    bool isOctalDigit(ushort c) const;

    int matchPunctuator(ushort c1, ushort c2,
                         ushort c3, ushort c4);
    ushort singleEscape(ushort c) const;
    ushort convertOctal(ushort c1, ushort c2,
                         ushort c3) const;
public:
    static unsigned char convertHex(ushort c1);
    static unsigned char convertHex(ushort c1, ushort c2);
    static QChar convertUnicode(ushort c1, ushort c2,
                                 ushort c3, ushort c4);
    static bool isIdentLetter(ushort c);
    static bool isDecimalDigit(ushort c);

    inline int ival() const { return qsyylval.ival; }
    inline double dval() const { return qsyylval.dval; }
    inline QScriptNameIdImpl *ustr() const { return qsyylval.ustr; }

private:
    void record8(ushort c);
    void record16(QChar c);

    int findReservedWord(const QChar *buffer, int size) const;

    const QChar *code;
    uint length;
    int yycolumn;
    int bol;     // begin of line

    union {
        int ival;
        double dval;
        QScriptNameIdImpl *ustr;
    } qsyylval;

    // current and following unicode characters
    ushort current, next1, next2, next3;

    struct keyword {
        const char *name;
        int token;
    };

    QString errmsg;
    bool wantRx;
    bool check_reserved;
};

} // namespace QScript

#endif


