/****************************************************************************+
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**+
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** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).+
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** All rights reserved.+
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** Contact: Nokia Corporation (qt-info@nokia.com)+
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**+
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** This file is part of the QLALR module of the Qt Toolkit.+
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**+
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** $QT_BEGIN_LICENSE:LGPL$+
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** No Commercial Usage+
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** This file contains pre-release code and may not be distributed.+
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** You may use this file in accordance with the terms and conditions+
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** contained in the Technology Preview License Agreement accompanying+
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** this package.+
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**+
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** GNU Lesser General Public License Usage+
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** Alternatively, this file may be used under the terms of the GNU Lesser+
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** General Public License version 2.1 as published by the Free Software+
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** Foundation and appearing in the file LICENSE.LGPL included in the+
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** packaging of this file.  Please review the following information to+
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** ensure the GNU Lesser General Public License version 2.1 requirements+
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** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.+
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**+
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** In addition, as a special exception, Nokia gives you certain additional+
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** rights.  These rights are described in the Nokia Qt LGPL Exception+
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** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.+
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**+
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** If you have questions regarding the use of this file, please contact+
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** Nokia at qt-info@nokia.com.+
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**+
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**+
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**+
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**+
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**+
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**+
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**+
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**+
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** $QT_END_LICENSE$+
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**+
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****************************************************************************/+
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+
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#include "lambda.h"+
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+
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#include <cstdio>+
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#include <cstdlib>+
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#include <cstring>+
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#include "parser_table_p.h"+
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+
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class Parser: protected parser_table+
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{+
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public:+
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    union Value {+
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      int ival;+
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      // ### more...+
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    };+
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+
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public:+
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    Parser();+
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    ~Parser();+
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+
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    bool parse();+
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+
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protected:+
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    inline void reallocateStack();+
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+
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    inline Value &sym(int index)+
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    { return sym_stack [tos + index - 1]; }+
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+
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    int nextToken();+
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    void consumeRule(int ruleno);+
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+
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protected:+
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    int tos;+
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    int stack_size;+
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    Value *sym_stack;+
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    int *state_stack;+
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    int current_char;+
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    unsigned in_tag: 1;+
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};+
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+
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inline void Parser::reallocateStack()+
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{+
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    if (! stack_size)+
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        stack_size = 128;+
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    else+
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        stack_size <<= 1;+
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+
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    sym_stack = reinterpret_cast<Value*> (::realloc(sym_stack, stack_size * sizeof(Value)));+
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    state_stack = reinterpret_cast<int*> (::realloc(state_stack, stack_size * sizeof(int)));+
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}+
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+
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Parser::Parser():+
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    tos(0),+
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    stack_size(0),+
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    sym_stack(0),+
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    state_stack(0)+
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{+
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}+
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+
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Parser::~Parser()+
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{+
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    if (stack_size) {+
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        ::free(sym_stack);+
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        ::free(state_stack);+
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    }+
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}+
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+
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bool Parser::parse()+
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{+
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  const int INITIAL_STATE = 0;+
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+
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  current_char = 0;+
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  in_tag = 0;+
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+
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  int yytoken = -1;+
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  reallocateStack();+
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+
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  tos = 0;+
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  state_stack[++tos] = INITIAL_STATE;+
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+
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  while (true)+
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    {+
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      if (yytoken == -1 && - TERMINAL_COUNT != action_index [state_stack [tos]])+
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        yytoken = nextToken();+
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+
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      int act = t_action (state_stack [tos], yytoken);+
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+
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      if (act == ACCEPT_STATE) {+
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        return true;+
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      }+
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+
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      else if (act > 0)+
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        {+
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          if (++tos == stack_size)+
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            reallocateStack();+
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+
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          sym_stack [tos].ival = current_char; // ### save the token value here+
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          state_stack [tos] = act;+
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          yytoken = -1;+
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        }+
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+
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      else if (act < 0)+
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        {+
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          int r = - act - 1;+
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+
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          tos -= rhs [r];+
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          act = state_stack [tos++];+
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          consumeRule (r);+
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          state_stack [tos] = nt_action (act, lhs [r] - TERMINAL_COUNT);+
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        }+
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+
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      else+
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        break;+
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    }+
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+
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    return false;+
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}+
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+
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+
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int Parser::nextToken()+
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{+
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    static int tokens[] = { ID, ID, ID, EOF_SYMBOL };+
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    static int *tk = tokens;+
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+
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    return *tk++;+
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}+
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+
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void Parser::consumeRule(int ruleno)+
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{+
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    switch (ruleno) {+
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    case Symbol:+
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        printf("symbol\n");+
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        break;+
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    case SubExpression:+
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        printf("sub-expr\n");+
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        break;+
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    case Appl:+
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        printf("appl\n");+
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        break;+
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    case Abstr:+
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        printf("abstr\n");+
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        break;+
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    }+
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}+
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+
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/////////////////////////////+
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// entry point+
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/////////////////////////////+
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int main()+
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{+
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    Parser parser;+
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+
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    if (parser.parse())+
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        printf ("OK\n");+
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    else+
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        printf ("KO\n");+
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}+
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+
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+
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