src/expression.h

   1 /*
   2   Copyright (c) 2006 Gábor Lehel <illissius@gmail.com>
   3
   4   This library is free software; you can redistribute it and/or
   5   modify it under the terms of the GNU Library General Public
   6   License as published by the Free Software Foundation; either
   7   version 2 of the License, or (at your option) any later version.
   8
   9   This library is distributed in the hope that it will be useful,
  10   but WITHOUT ANY WARRANTY; without even the implied warranty of
  11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12   Library General Public License for more details.
  13
  14   You should have received a copy of the GNU Library General Public License
  15   along with this library; see the file COPYING.LIB.  If not, write to
  16   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17   Boston, MA 02110-1301, USA.
  18 */
  19
  20 #ifndef AMAROK_EXPRESSION_H
  21 #define AMAROK_EXPRESSION_H
  22
  23 #include <QList>
  24 #include <QString>
  25
  26 struct expression_element
  27 {
  28     QString field;
  29     QString text;
  30     bool negate: 1;
  31     enum { Contains, Less, More } match: 2;
  32     expression_element(): negate( false ), match( Contains ) { }
  33 };
  34 typedef QList<expression_element> or_list;
  35
  36 typedef QList<or_list> ParsedExpression;
  37
  38 class ExpressionParser
  39 {
  40     public:
  41         ExpressionParser( const QString &expression );
  42         ParsedExpression parse();
  43         static ParsedExpression parse( const QString &expression );
  44
  45         static bool isAdvancedExpression( const QString &expression );
  46
  47     private:
  48         void parseChar(   const QChar &c );
  49         void handleSpace( const QChar &c );
  50         void handleMinus( const QChar &c );
  51         void handleColon( const QChar &c );
  52         void handleMod(   const QChar &c );
  53         void handleQuote( const QChar &c );
  54         void handleChar(  const QChar &c );
  55         void finishedToken();
  56         void finishedElement();
  57         void finishedOrGroup();
  58
  59         const QString &m_expression;
  60         enum State { ExpectMinus, ExpectField, ExpectMod, ExpectText };
  61         int m_state;
  62         bool m_haveGroup;
  63         bool m_inQuote;
  64         bool m_inOrGroup;
  65         QString m_string;
  66         expression_element m_element;
  67         or_list m_or;
  68         ParsedExpression m_parsed;
  69 };
  70
  71
  72 #endif