Method Parse

Common/Misc/vtkFunctionParser.cxx:93–153

}

int vtkFunctionParser::Parse()
{
  int result;
  int i;

  if (this->Function == nullptr)
  {
    vtkErrorMacro("Parse: no function has been set");
    return 0;
  }

  result = this->CheckSyntax();
  if (!result)
  {
    return 0;
  }

  this->BuildInternalFunctionStructure();

  // need to make sure that the ambiguous operators are correct
  // - scalar/vector +
  // - scalar/vector -
  // - scalar/vector unary minus
  // - scalar/vector unary plus
  // - * (2 scalars) or scalar multiple (scalar, vector)
  result = this->DisambiguateOperators();
  if (!result)
  {
    vtkErrorMacro("Parse: Error deciding between ambiguous operators");
    return 0;
  }

  // need to recalculate stack size based on number of vector variables
  // in byte code
  for (i = 0; i < this->ByteCodeSize; i++)
  {
    if ((this->ByteCode[i] >= VTK_PARSER_BEGIN_VARIABLES +
            static_cast<unsigned int>(this->GetNumberOfScalarVariables())) ||
      (this->ByteCode[i] == VTK_PARSER_IHAT) || (this->ByteCode[i] == VTK_PARSER_JHAT) ||
      (this->ByteCode[i] == VTK_PARSER_KHAT))
    {
      this->StackSize += 2;
    }
  }

  if (this->StackSize)
  {
    this->Stack = new double[this->StackSize];
    if (!this->Stack)
    {
      vtkErrorMacro("Parse: Out of memory");
      return 0;
    }
  }

  // Collect meta-data about variables that are needed for evaluation of the
  // function.
  this->UpdateNeededVariables();