parser.cpp

/***************************************************************************
                           parser.cpp
                           -------------------
    begin                : 2003-05-10
    copyright            : (C) 2004-2005 by Michael Menne
    email                : menne@users.sourceforge.net
    history              : 1.0 - 10.05.2003 - Zelda 3 Clone
                           1.1 - 14.04.2004 - WDS Maptool
                           1.2 - 17.04.2004 - ProSys - FHD
 ***************************************************************************/

/***************************************************************************
 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.

 This program 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 General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 ***************************************************************************/

#include "parser.h"
#include <stdio.h>
#include <string.h>

/*----------------------------------------------------------------------------/
    Constructor / Desstructor
-----------------------------------------------------------------------------*/

CParser::CParser()
{
    m_pBuffer  = NULL;
    m_pBufEnd  = NULL;
    m_pFileMem = NULL;
}

CParser::~CParser()
{
    if(m_pFileMem != NULL)
    {
        delete [] m_pFileMem;
        m_pFileMem = NULL;
    }
}

/*---------------------------------------------------------------------------
    Methods:
---------------------------------------------------------------------------*/

void CParser::StartParseBuffer(const unsigned char *pBuffer, const int nSize)
{
    m_pBuffer = pBuffer;
    m_pBufEnd = pBuffer + nSize;
    m_nScriptLine = 1;
}

void CParser::StartParseString(const char *szString)
{
    m_pBuffer = (unsigned char*) szString;
    m_pBufEnd = (unsigned char*) szString + strlen(szString);
    m_nScriptLine = 1;
}

bool CParser::StartParseFile(const char *szFile)
{
    FILE *pFile = fopen(szFile, "r");
    if(!pFile)
        return false;

    fseek(pFile, 0L, SEEK_END);
    int nSize = ftell(pFile);
    rewind(pFile);

    m_pFileMem = new unsigned char[nSize];
    memset( m_pFileMem, 0, nSize );
    fread(m_pFileMem, nSize, 1, pFile);     // ToDo: Error checking

    // Set starting and end point
    m_pBuffer = m_pFileMem;
    m_pBufEnd = m_pFileMem + nSize;
    m_nScriptLine = 1;

    fclose( pFile );
    return true;
}

/*
 * If bCrossline is false, NextToken returns false when a line break is found
 * NextToken(true)  returns 0 only if end of file
 * NextToken(false) returns 0 if line break or end of file
 */
bool CParser::NextToken(bool bCrossline)
{
    char    *token_p;

    if( !m_pBuffer || m_pBuffer==m_pBufEnd )
        return 0;

    *m_szToken = 0; // init to zero


// skip space
skipspace:
    while(*m_pBuffer <= 32 || *m_pBuffer == '\n' || *m_pBuffer == ';')
    {

        if( m_pBuffer >= m_pBufEnd )
        {
            if( !bCrossline )
            {
                // ("Line %i is incomplete", m_nScriptLine )
            }
            return 0;
        }

        if( !bCrossline )
        {
            if( *m_pBuffer=='\n' || *m_pBuffer==';' )
                return 0;
        }
        else if(*m_pBuffer == '\n')
        {
            m_nScriptLine++;
        }

        m_pBuffer++;
    }

    if( m_pBuffer >= m_pBufEnd )
        return 0;

    // # // comments
    if( *m_pBuffer == '#' || ( m_pBuffer[0] == '/' && m_pBuffer[1] == '/' ) )
    {
        while(*m_pBuffer++ != '\n')
        {
            if( m_pBuffer >= m_pBufEnd )
                return 0;
        }
        m_nScriptLine++;
        if( !bCrossline )
            return 0;
        goto skipspace;
    }

    // /* */ comments
    if( m_pBuffer[0] == '/' && m_pBuffer[1] == '*' )
    {
        m_pBuffer+=2;
        while( !(m_pBuffer[0] == '*' && m_pBuffer[1] == '/') )
        {
            m_pBuffer++;
            if (m_pBuffer >= m_pBufEnd)
            {
                //("*** Error: Premature end of file, '/*' without '*/'")
                return 0;
            }
            if(*m_pBuffer == '\n')
                m_nScriptLine++;
        }
        m_pBuffer += 2;
        goto skipspace;
    }


    /*
     * copy m_szToken
     */
    token_p = m_szToken;

    if (*m_pBuffer == '"')  // quoted m_szToken
    {
        m_pBuffer++;
        while( *m_pBuffer != '"' )
        {
            *token_p++ = *m_pBuffer++;
            if( m_pBuffer == m_pBufEnd )
                break;

            if( token_p == &m_szToken[MAXTOKEN] )
            {
                //("*** Error, Token too large on line %i\n",m_nScriptLine)
            }
        }
        m_pBuffer++;
    }
    else    // regular m_szToken
    {
        if( *m_pBuffer == '{' || *m_pBuffer == '}' )
        {
            *token_p++ = *m_pBuffer++;
            *token_p = 0;
            return 1;
        }

        while( *m_pBuffer > 32 && *m_pBuffer != '\n' && *m_pBuffer != ';' && *m_pBuffer !='{' && *m_pBuffer !='}')
        {
            *token_p++ = *m_pBuffer++;
            if( m_pBuffer == m_pBufEnd)
                break;

            if( token_p == &m_szToken[MAXTOKEN])
            {
                //("*** Error, Token too large on line %i\n", m_nScriptLine)
            }
        }
    }

    *token_p = 0;

    return 1;
}

int CParser::SkipLine( )
{
    int n = 0;
    while( NextToken( false) )
        n++;
    return n;
}

// kate: space-indent off; tab-width 4; replace-tabs off;

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