SystemCallDeleteVariable.cpp

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#ifndef _MADARA_NO_KARL_


#include "madara/expression/LeafNode.h"
#include "madara/expression/SystemCallDeleteVariable.h"
#include "madara/knowledge/ThreadSafeContext.h"
#include "madara/expression/Visitor.h"


madara::expression::SystemCallDeleteVariable::SystemCallDeleteVariable (
  madara::knowledge::ThreadSafeContext & context,
  const ComponentNodes & nodes)
  : SystemCallNode (context, nodes)
{

}

// Dtor
madara::expression::SystemCallDeleteVariable::~SystemCallDeleteVariable (void)
{
}

madara::knowledge::KnowledgeRecord
madara::expression::SystemCallDeleteVariable::item (void) const
{
  return madara::knowledge::KnowledgeRecord (nodes_.size ());
}

madara::knowledge::KnowledgeRecord
madara::expression::SystemCallDeleteVariable::prune (bool & can_change)
{
  // user can always change a function, and we have no control over
  // what it does. Consequently, a function node cannot be pruned out
  // under any situation
  can_change = true;
  
  madara::knowledge::KnowledgeRecord result;

  if (nodes_.size () == 1)
  {
    bool arg_can_change = false;
    result = nodes_[0]->prune (arg_can_change);
    
    if (!arg_can_change && dynamic_cast <LeafNode *> (nodes_[0]) == 0)
    {
      delete nodes_[0];
      nodes_[0] = new LeafNode (*(this->logger_), result);
    }
  }
  else
  {
    madara_logger_ptr_log (logger_, logger::LOG_ERROR,
      "madara::expression::SystemCallDeleteVariable: "
      "KARL COMPILE ERROR:"
      "System call delete_variable requires 1 argument,"
      "e.g., #delete_variable ('var')\n");

    throw KarlException ("madara::expression::SystemCallDeleteVariable: "
      "KARL COMPILE ERROR: "
      "System call delete_variable requires 1 argument,"
      "e.g., #delete_variable ('var')\n"); 
  }


  return result;
}

madara::knowledge::KnowledgeRecord 
madara::expression::SystemCallDeleteVariable::evaluate (
const madara::knowledge::KnowledgeUpdateSettings & settings)
{
  knowledge::KnowledgeRecord return_value;

  if (nodes_.size () == 1)
  {
    madara_logger_ptr_log (logger_, logger::LOG_MINOR,
      "madara::expression::SystemCallDeleteVariable: "
      "System call delete_variable is returning the clock "
      "of its first argument\n");

    return madara::knowledge::KnowledgeRecord (
      context_.delete_variable (
        nodes_[0]->evaluate (settings).to_string ()));
  }
  else
  {
    madara_logger_ptr_log (logger_, logger::LOG_ERROR,
      "madara::expression::SystemCallDeleteVariable: "
      "KARL RUNTIME ERROR:"
      "System call delete_variable requires 1 argument,"
      "e.g., #delete_variable ('var')\n");

    throw KarlException ("madara::expression::SystemCallDeleteVariable: "
      "KARL RUNTIME ERROR: "
      "System call delete_variable requires 1 argument,"
      "e.g., #delete_variable ('var')\n"); 
  }

  return return_value;
}

// accept a visitor
void 
madara::expression::SystemCallDeleteVariable::accept (
  madara::expression::Visitor &visitor) const
{
  visitor.visit (*this);
}

#endif // _MADARA_NO_KARL_