/*  Copyright (c) 2006 Gábor Lehel <illissius@gmail.com>  This library is free software; you can redistribute it and/or  modify it under the terms of the GNU Library General Public  License as published by the Free Software Foundation; either  version 2 of the License, or (at your option) any later version.  This library is distributed in the hope that it will be useful,  but WITHOUT ANY WARRANTY; without even the implied warranty of  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  Library General Public License for more details.  You should have received a copy of the GNU Library General Public License  along with this library; see the file COPYING.LIB.  If not, write to  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,  Boston, MA 02110-1301, USA.*/#include "expression.h"ExpressionParser::ExpressionParser( const QString &expression )    : m_expression( expression )    , m_state( ExpectMinus )    , m_haveGroup( false )    , m_inQuote( false )    , m_inOrGroup( false ){ }ParsedExpression ExpressionParser::parse(){    const uint length = m_expression.length();    for( uint pos = 0; pos < length; ++pos )        parseChar( m_expression.constref( pos ) );    finishedToken();    finishedOrGroup();    return m_parsed;}ParsedExpression ExpressionParser::parse( const QString &expression ) //static{    ExpressionParser p( expression );    return p.parse();}bool ExpressionParser::isAdvancedExpression( const QString &expression ) //static{    return ( expression.contains( '"'   ) ||             expression.contains( ':'   ) ||             expression.contains( '-'   ) ||             expression.contains( "AND" ) ||             expression.contains( "OR"  ) );}/* PRIVATE */void ExpressionParser::parseChar( const QChar &c ){    if( m_inQuote && c != '"' )        m_string += c;    else if( c.isSpace() )        handleSpace( c );    else if( c == '-' )        handleMinus( c );    else if( c == ':' )        handleColon( c );    else if( c == '>' || c == '<' )        handleMod( c );    else if( c == '"' )        handleQuote( c );    else        handleChar( c );}void ExpressionParser::handleSpace( const QChar& ){    if( m_state > ExpectMinus )        finishedToken();}void ExpressionParser::handleMinus( const QChar &c ){    if( m_state == ExpectMinus )    {        m_element.negate = true;        m_state = ExpectField;    }    else        handleChar( c );}void ExpressionParser::handleColon( const QChar &c ){    if( m_state <= ExpectField && !m_string.isEmpty() )    {        m_element.field = m_string;        m_string = QString::null;        m_state = ExpectMod;    }    else        handleChar( c );}void ExpressionParser::handleMod( const QChar &c ){    if( m_state == ExpectMod )    {        m_element.match = ( c == '>' ) ? expression_element::More : expression_element::Less;        m_state = ExpectText;    }    else        handleChar( c );}void ExpressionParser::handleQuote( const QChar& ){    if( m_inQuote )    {        finishedElement();        m_inQuote = false;    }    else    {        if( !m_string.isEmpty() )            finishedToken();        m_state = ExpectText;        m_inQuote = true;    }}void ExpressionParser::handleChar( const QChar &c ){    m_string += c;    if( m_state <= ExpectField )        m_state = ExpectField;    else if( m_state <= ExpectText )        m_state = ExpectText;}void ExpressionParser::finishedToken(){    enum { And, Or, Neither };    int s;    if( m_haveGroup || !m_element.field.isEmpty() )        s = Neither;    else if( m_string == "AND" )        s = And;    else if( m_string == "OR" )        s = Or;    else        s = Neither;    if( s == Neither )        finishedElement();    else    {        m_haveGroup = true;        if( s == Or )            m_inOrGroup = true;        else            finishedOrGroup();        m_string = QString::null;        m_state = ExpectMinus;    }}void ExpressionParser::finishedElement(){    if( !m_inOrGroup )        finishedOrGroup();    m_inOrGroup = m_haveGroup = false;    m_element.text = m_string;    m_string = QString::null;    if( !m_element.text.isEmpty() || !m_element.field.isEmpty() )        m_or.append( m_element );    m_element = expression_element();    m_state = ExpectMinus;}void ExpressionParser::finishedOrGroup(){    if( !m_or.isEmpty() )        m_parsed.append( m_or );    m_or.clear();    m_inOrGroup = false;}