vmcalcexpressionanalyzer.cpp

TOOL (Tiny Object Oriented Language) is an easily-embedded, object-oriented, C++-like-language inter

/*****************************************************************************/
/*                              SOURCE FILE                                  */
/*****************************************************************************/
/*
       $Archive:   $

      $Revision:   $
          $Date:   $
        $Author:   $

    Description:   Implementation of the Expression Analyzer class

                      TOOL And XML FORMS License
                      ==========================

                      Except where otherwise noted, all of the documentation 
                      and software included in the TOOL package is 
                      copyrighted by Michael Swartzendruber.

                      Copyright (C) 2005 Michael John Swartzendruber. 
                      All rights reserved.

                      Access to this code, whether intentional or accidental,
                      does NOT IMPLY any transfer of rights.

                      This software is provided "as-is," without any express 
                      or implied warranty. In no event shall the author be held
                      liable for any damages arising from the use of this software.

                      Permission is granted to anyone to use this software for 
                      any purpose, including commercial applications, and to 
                      alter and redistribute it, provided that the following 
                      conditions are met:

                      1. All redistributions of source code files must retain 
                         all copyright notices that are currently in place, 
                         and this list of conditions without modification.

                      2. The origin of this software must not be misrepresented;
                         you must not claim that you wrote the original software.

                      3. If you use this software in another product, an acknowledgment
                         in the product documentation would be appreciated but is
                         not required.

                      4. Modified versions in source or binary form must be plainly 
                         marked as such, and must not be misrepresented as being 
                         the original software.
*/
static char OBJECT_ID[] = "$Revision:   $ : $Date:   $";
/*****************************************************************************/


#include <math.h>
#include <ctype.h>
#include "VMCalcExpressionAnalyzer.h"


// Error code var
//
int giResultCode;


void VMCalcExpressionAnalyzer::PruneTree( PNODE pxRoot )
{
  if ( NULL == pxRoot ) 
    return;

  if ( pxRoot->m_pxLeft != NULL ) 
    PruneTree( pxRoot->m_pxLeft );

  if ( pxRoot->m_pxRight != NULL ) 
    PruneTree( pxRoot->m_pxRight );

  if ( pxRoot->m_ucOperation == '`' )
    delete pxRoot->m_oValueString;

  delete pxRoot;
}


VMCalcExpressionAnalyzer::VMCalcExpressionAnalyzer( void )
{
  m_xExpressionTree = NULL;
  m_oEquation       = "";
  m_iPosition       = 0;
  m_poVariables     = NULL;
}


VMCalcExpressionAnalyzer::VMCalcExpressionAnalyzer( CMapVariable* pVarsMap )
{
  m_xExpressionTree = NULL;
  m_oEquation       = "";
  m_iPosition       = 0;
  m_poVariables     = pVarsMap;
}


VMCalcExpressionAnalyzer::~VMCalcExpressionAnalyzer( void )
{
  PruneTree( m_xExpressionTree );
}


int VMCalcExpressionAnalyzer::UpdateValue( void )
{
  if ( m_oEquation.empty() )
    return( 0 );

  PruneTree( m_xExpressionTree );

  m_xExpressionTree = NULL;
  m_iPosition       = 0;
  m_xExpressionTree = FactorSumDiff();

  if ( m_oEquation[ m_iPosition ] != '\0' ) 
  {
    PruneTree( m_xExpressionTree );
    m_xExpressionTree = NULL;
  }

  if ( NULL == m_xExpressionTree )
    return( m_iPosition );
  else 
    return( -1 );
}


VMCalcExpressionAnalyzer::PNODE VMCalcExpressionAnalyzer::FactorSumDiff( void )
{
  SkipSpaces();

  PNODE pxNewNode;
  PNODE pxLHS = FactorMultDiv();
  PNODE pxRHS;

  if ( NULL == pxLHS ) 
    return( NULL );

  SkipSpaces();

  while ( ( m_oEquation[ m_iPosition ] == '-' ) 
       || ( m_oEquation[ m_iPosition ] == '+' ) ) 
  {
    pxNewNode = new NODE;

    pxNewNode->m_pxLeft      = pxLHS;
    pxNewNode->m_ucOperation = m_oEquation[ m_iPosition ];

    m_iPosition++;

    pxRHS = FactorMultDiv();
    pxNewNode->m_pxRight = pxRHS;

    if ( NULL == pxRHS ) 
    {
      PruneTree( pxNewNode );
      return( NULL );
    }
    pxLHS = pxNewNode;
  }
  return( pxLHS );
}


VMCalcExpressionAnalyzer::PNODE VMCalcExpressionAnalyzer::FactorMultDiv( void )
{
  SkipSpaces();

  PNODE pxNewNode;
  PNODE pxLHS = Compute();
  PNODE pxRHS;

  if ( NULL == pxLHS ) 
    return( NULL );

  SkipSpaces();

  while ( ( m_oEquation[ m_iPosition ] == '*' ) 
       || ( m_oEquation[ m_iPosition ] == '/' ) ) 
  {
    pxNewNode = new NODE;
    pxNewNode->m_pxLeft      = pxLHS;
    pxNewNode->m_ucOperation = m_oEquation[ m_iPosition ];

    m_iPosition++;

    pxRHS = Compute();
    pxNewNode->m_pxRight = pxRHS;

    if ( NULL == pxRHS ) 
    {
      PruneTree( pxNewNode );
      return( NULL );
    }
    pxLHS = pxNewNode;
  }
  return( pxLHS );
}


VMCalcExpressionAnalyzer::PNODE VMCalcExpressionAnalyzer::Compute( void )
{
  SkipSpaces();

  PNODE pxNewNode = NULL;
  PNODE pxLHS = PerformLogicalOperation();
  PNODE pxRHS;

  if ( NULL == pxLHS ) 
    return( NULL );

  SkipSpaces();

  while ( m_oEquation[ m_iPosition ] == '^' ) 
  {
    pxNewNode = new NODE;
    pxNewNode->m_pxLeft      = pxLHS;
    pxNewNode->m_ucOperation = m_oEquation[ m_iPosition ];

    m_iPosition++;

    pxRHS = PerformLogicalOperation();
    pxNewNode->m_pxRight = pxRHS;

    if ( NULL == pxRHS ) 
    {
      PruneTree( pxNewNode );
      return( NULL );
    }
    pxLHS = pxNewNode;
  }
  return( pxLHS );
}


VMCalcExpressionAnalyzer::PNODE VMCalcExpressionAnalyzer::FactorExpression( void )
{
  SkipSpaces();

  PNODE pxNewNode  = NULL;
  PNODE pxRHS = NULL;
  PNODE pxLHS = NULL;

  while ( m_oEquation[ m_iPosition ] == ' ' 
       && m_oEquation[ m_iPosition ] != '\0' )
    m_iPosition++;

  SkipSpaces();

  if ( m_oEquation[ m_iPosition ] == '-' )
  {
    pxNewNode  = new NODE;
    pxLHS      = new NODE;

    pxLHS->m_pxRight = NULL;
    pxLHS->m_pxLeft = NULL;

    pxLHS->m_ucOperation      = '@';
    pxLHS->m_dValue           = -1;

    pxNewNode->m_pxLeft       = pxLHS;
    pxNewNode->m_ucOperation  = '*';

    m_iPosition++;

    pxNewNode->m_pxRight = FactorSumDiff();

    if ( NULL == pxNewNode->m_pxRight ) 
      return( NULL );

    return( pxNewNode );   
  }
  if ( m_oEquation[ m_iPosition ] == '(' )
  {
    m_iPosition++;
    pxNewNode = FactorSumDiff();

    if ( NULL == pxNewNode ) 
      return( NULL );

    if ( m_oEquation[ m_iPosition ] != ')' )
    {
      PruneTree( pxNewNode );
      return( NULL );
    }
    m_iPosition++;
    return( pxNewNode );
  }
  else 
  if ( m_oEquation[ m_iPosition ] == '|' )
  {
    m_iPosition++;
    pxRHS = FactorSumDiff();

    if ( NULL == pxRHS ) 
      return( NULL );

    if ( m_oEquation[ m_iPosition ] != '|' )
    {
      PruneTree( pxNewNode );
      return( NULL );
    }
    pxNewNode = new NODE;
    pxNewNode->m_pxLeft      = pxRHS;
    pxNewNode->m_pxRight     = NULL;
    pxNewNode->m_ucOperation = '|';

    m_iPosition++;
    return( pxNewNode );
  }
  else 
    return( FactorString() );

  return( pxNewNode );
}


VMCalcExpressionAnalyzer::PNODE VMCalcExpressionAnalyzer::FactorString( void )
{
  SkipSpaces();

  VMCalcValueBase* poValue;
  int        iPosition;
  PNODE      pxNewNode = NULL;
  PNODE      pxLHS     = NULL;
  PNODE      pxReturn  = NULL;
  bool       bNegative = false;

  iPosition = m_iPosition;
 
  SkipSpaces();

  if ( m_oEquation[ m_iPosition ]== '\0' ) 
    pxReturn = NULL;

  if ( m_oEquation[ m_iPosition ]== '-' ) 
  {
    bNegative = true;
    iPosition++;
    m_iPosition++;
  }

  if ( isdigit( m_oEquation[ m_iPosition ] ) )
  {
    while ( isdigit( m_oEquation[ m_iPosition ] ) )
      m_iPosition++;

    if ( m_oEquation[ m_iPosition ] == '.' )
      m_iPosition++;

    while ( isdigit( m_oEquation[ m_iPosition ] ) )
      m_iPosition++;

    pxNewNode = new NODE;
    pxNewNode->m_pxLeft      = NULL; 
    pxNewNode->m_pxRight     = NULL;
    pxNewNode->m_ucOperation = '@';
    pxNewNode->m_dValue      = atof( m_oEquation.substr( iPosition, m_iPosition - iPosition ).c_str() );

    if ( bNegative )
    {
      pxNewNode->m_dValue *= -1;
    }

    pxReturn = pxNewNode;
  }

  if ( isalpha( m_oEquation[ m_iPosition ] ) 
    || m_oEquation[ m_iPosition ] == '_' 
    || m_oEquation[ m_iPosition ] == '$' )
  {
    while ( isalnum( m_oEquation[ m_iPosition ] ) 
         || m_oEquation[ m_iPosition ] == '_' 
         || m_oEquation[ m_iPosition ] == '$' )
      m_iPosition++;

    std::string oToken  = m_oEquation.substr( iPosition, 
                                              m_iPosition - iPosition );
    std::string oVarName = oToken;
    std::string::iterator oStringIter = oToken.begin();
    while ( oStringIter != oToken.end() )
    {
      *(oStringIter) = toupper( *(oStringIter) );
      oStringIter++;
    }

    if ( oToken == "SIN" )
    {
      pxLHS = FactorExpression();
      pxNewNode = new NODE;

      pxNewNode->m_pxLeft      = pxLHS;
      pxNewNode->m_pxRight     = NULL;
      pxNewNode->m_ucOperation = 150;

      SkipSpaces();
      return( pxNewNode );
    }
    if ( oToken =="COS" )
    {
      pxLHS = FactorExpression();
      pxNewNode = new NODE;

      pxNewNode->m_pxLeft      = pxLHS;
      pxNewNode->m_pxRight     = NULL;
      pxNewNode->m_ucOperation = 151;

      SkipSpaces();
      return( pxNewNode );
    }
    if ( oToken == "EXP" )
    {
      pxLHS = FactorExpression();
      pxNewNode = new NODE;

      pxNewNode->m_pxLeft      = pxLHS;
      pxNewNode->m_pxRight     = NULL;
      pxNewNode->m_ucOperation = 152;

      SkipSpaces();
      return( pxNewNode );
    }
    if ( oToken =="SQRT" )
    {
      pxLHS = FactorExpression();
      pxNewNode = new NODE;

      pxNewNode->m_pxLeft      = pxLHS;
      pxNewNode->m_pxRight     = NULL;
      pxNewNode->m_ucOperation = 153;

      SkipSpaces();
      return( pxNewNode );
    }
    if ( oToken =="LN" )
    {
      pxLHS = FactorExpression();
      pxNewNode = new NODE;

      pxNewNode->m_pxLeft      = pxLHS;
      pxNewNode->m_pxRight     = NULL;
      pxNewNode->m_ucOperation = 154;

      SkipSpaces();
      return( pxNewNode );
    }
    if ( oToken =="TAN" )
    {
      pxLHS = FactorExpression();
      pxNewNode = new NODE;

      pxNewNode->m_pxLeft      = pxLHS;
      pxNewNode->m_pxRight     = NULL;
      pxNewNode->m_ucOperation = 155;

      SkipSpaces();
      return( pxNewNode );
    }
    if ( oToken =="CTG" )
    {
      pxLHS = FactorExpression();
      pxNewNode = new NODE;

      pxNewNode->m_pxLeft      = pxLHS;
      pxNewNode->m_pxRight     = NULL;
      pxNewNode->m_ucOperation = 156;

      SkipSpaces();
      return( pxNewNode );
    }
    if ( oToken =="ASIN" )
    {
      pxLHS = FactorExpression();
      pxNewNode = new NODE;

      pxNewNode->m_pxLeft      = pxLHS;
      pxNewNode->m_pxRight     = NULL;
      pxNewNode->m_ucOperation = 157;

      SkipSpaces();
      return( pxNewNode );
    }
    if ( oToken =="ACOS" )
    {
      pxLHS = FactorExpression();
      pxNewNode = new NODE;

      pxNewNode->m_pxLeft      = pxLHS;
      pxNewNode->m_pxRight     = NULL;
      pxNewNode->m_ucOperation = 158;

      SkipSpaces();
      return( pxNewNode );
    }
    if ( oToken =="ATAN" )
    {
      pxLHS = FactorExpression();
      pxNewNode = new NODE;

      pxNewNode->m_pxLeft      = pxLHS;
      pxNewNode->m_pxRight     = NULL;
      pxNewNode->m_ucOperation = 159;

      SkipSpaces();
      return( pxNewNode );
    }

    if ( oToken =="SINH" )
    {
      pxLHS = FactorExpression();
      pxNewNode = new NODE;

      pxNewNode->m_pxLeft      = pxLHS;
      pxNewNode->m_pxRight     = NULL;
      pxNewNode->m_ucOperation = 160;

      SkipSpaces();
      return( pxNewNode );
    }
    if ( oToken =="COSH" )
    {
      pxLHS = FactorExpression();
      pxNewNode = new NODE;

      pxNewNode->m_pxLeft      = pxLHS;
      pxNewNode->m_pxRight     = NULL;
      pxNewNode->m_ucOperation = 161;

      SkipSpaces();
      return( pxNewNode );
    }
    if ( oToken =="TANH" )
    {
      pxLHS = FactorExpression();
      pxNewNode = new NODE;