SystemCallGeneric.h

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#ifndef MADARA_SYSTEM_CALL_GENERIC_H_
#define MADARA_SYSTEM_CALL_GENERIC_H_
 
#ifndef _MADARA_NO_KARL_
 
#include <string>
#include <stdexcept>
#include <functional>
#include "madara/utility/StdInt.h"
#include "madara/expression/SystemCallNode.h"
#include "madara/expression/Visitor.h"
 
namespace madara
{
namespace expression
{
class SystemCallGeneric : public SystemCallNode
{
public:
  using fn_signature = madara::knowledge::KnowledgeRecord(
      std::vector<madara::knowledge::KnowledgeRecord>);
 
  using fn_type = std::function<fn_signature>;
 
  SystemCallGeneric(madara::knowledge::ThreadSafeContext& context,
      const ComponentNodes& nodes, const char* name, fn_type fn)
    : SystemCallNode(context, nodes), name_(name), fn_(fn)
  {
  }
 
  virtual madara::knowledge::KnowledgeRecord item(void) const
  {
    return madara::knowledge::KnowledgeRecord(nodes_.size());
  }
 
  virtual madara::knowledge::KnowledgeRecord prune(bool& can_change)
  {
    can_change = true;
    return {};
  }
 
  virtual madara::knowledge::KnowledgeRecord evaluate(
      const madara::knowledge::KnowledgeUpdateSettings& settings)
  {
    std::vector<madara::knowledge::KnowledgeRecord> args;
    args.reserve(nodes_.size());
    for (const auto& node : nodes_)
    {
      args.emplace_back(node->evaluate(settings));
    }
    return fn_(std::move(args));
  }
 
  virtual void accept(Visitor& visitor) const
  {
    visitor.visit(*this);
  }
 
  const char* name() const
  {
    return name_;
  }
 
private:
  const char* name_;
  fn_type fn_;
};
}
}
 
#endif  // _MADARA_NO_KARL_
 
#endif  // MADARA_SYSTEM_CALL_GENERIC_H_