SystemCallFragment.cpp

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#ifndef _MADARA_NO_KARL_


#include "madara/expression/LeafNode.h"
#include "madara/expression/SystemCallFragment.h"
#include "madara/expression/Visitor.h"


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

}

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

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

madara::knowledge::KnowledgeRecord
madara::expression::SystemCallFragment::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;
  
  for (ComponentNodes::iterator i = nodes_.begin (); i != nodes_.end ();
       ++i)
  {
    bool arg_can_change = false;
    result = (*i)->prune (arg_can_change);
    
    if (!arg_can_change && dynamic_cast <LeafNode *> (*i) == 0)
    {
      delete *i;
      *i = new LeafNode (*(this->logger_), result);
    }
  }

  if (nodes_.size () != 3)
  {
    madara_logger_ptr_log (logger_, logger::LOG_MINOR,
      "KARL COMPILE ERROR: System call fragment"
      " requires three arguments, e.g."
      " #fragment ('hello world', 0, 4) will return 'hello'\n");
  }

  return result;
}

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

  if (nodes_.size () == 3)
  {
    // grab the first and last ranges
    unsigned int first =
      (unsigned int) nodes_[1]->evaluate (settings).to_integer ();
    unsigned int  last =
      (unsigned int) nodes_[2]->evaluate (settings).to_integer ();

    madara_logger_ptr_log (logger_, logger::LOG_MINOR,
      "System call fragment is returning segment [%d-%d].\n",
      first, last);
    
    return nodes_[0]->evaluate (settings).fragment (first, last);
  }

  else
  {
    madara_logger_ptr_log (logger_, logger::LOG_EMERGENCY,
      "KARL RUNTIME ERROR: System call fragment"
      " requires three arguments, e.g."
      " #fragment ('hello world', 0, 4) will return 'hello'\n");
  }


  return return_value;
}

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

#endif // _MADARA_NO_KARL_