SystemCallClearVariable.cpp

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#ifndef _MADARA_NO_KARL_
 
#include "madara/expression/LeafNode.h"
#include "madara/expression/SystemCallClearVariable.h"
#include "madara/knowledge/ThreadSafeContext.h"
#include "madara/expression/Visitor.h"
 
madara::expression::SystemCallClearVariable::SystemCallClearVariable(
    madara::knowledge::ThreadSafeContext& context, const ComponentNodes& nodes)
  : SystemCallNode(context, nodes)
{
}
 
// Dtor
madara::expression::SystemCallClearVariable::~SystemCallClearVariable(void) {}
 
madara::knowledge::KnowledgeRecord
madara::expression::SystemCallClearVariable::item(void) const
{
  return madara::knowledge::KnowledgeRecord(nodes_.size());
}
 
madara::knowledge::KnowledgeRecord
madara::expression::SystemCallClearVariable::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::SystemCallClearVariable: "
        "KARL COMPILE ERROR:"
        "System call clear requires 1 argument,"
        "e.g., #clear ('var')\n");
 
    throw exceptions::KarlException(
        "madara::expression::SystemCallClearVariable: "
        "KARL COMPILE ERROR: "
        "System call clear requires 1 argument,"
        "e.g., #clear ('var')\n");
  }
 
  return result;
}
 
madara::knowledge::KnowledgeRecord
madara::expression::SystemCallClearVariable::evaluate(
    const madara::knowledge::KnowledgeUpdateSettings& settings)
{
  knowledge::KnowledgeRecord return_value;
 
  if (nodes_.size() == 1)
  {
    std::string name = nodes_[0]->evaluate(settings).to_string();
 
    madara_logger_ptr_log(logger_, logger::LOG_MINOR,
        "madara::expression::SystemCallClearVariable: "
        "System call clear is clearing variable "
        "%s\n",
        name.c_str());
 
    return knowledge::KnowledgeRecord(context_.clear(name));
  }
  else
  {
    madara_logger_ptr_log(logger_, logger::LOG_ERROR,
        "madara::expression::SystemCallClearVariable: "
        "KARL RUNTIME ERROR:"
        "System call clear requires 1 argument,"
        "e.g., #clear ('var')\n");
 
    throw exceptions::KarlException(
        "madara::expression::SystemCallClearVariable: "
        "KARL RUNTIME ERROR: "
        "System call clear requires 1 argument,"
        "e.g., #clear ('var')\n");
  }
 
  return return_value;
}
 
// accept a visitor
void madara::expression::SystemCallClearVariable::accept(
    madara::expression::Visitor& visitor) const
{
  visitor.visit(*this);
}
 
#endif  // _MADARA_NO_KARL_