state_utils.h

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#ifndef actasp_state_util_h__guard
#define actasp_state_util_h__guard

#include <actasp/AspFluent.h>

#include <functional>
#include <set>

namespace actasp {

template<typename FluentClass> //typically AspFluent, possibly AspFluentRef
struct StateComparator : public std::binary_function<std::set<FluentClass>,std::set<FluentClass>, bool> {
    
  bool operator()(const std::set<FluentClass> &first,const std::set<FluentClass> &second) const {


    if (first.size() != second.size())
      return first.size() < second.size();

    //they have the same number of fluents
    typename std::set<FluentClass>::const_iterator thisV = first.begin();
    typename std::set<FluentClass>::const_iterator otherV = second.begin();

    ActionComparator lessThen; //ignores the time steps!

    for (; thisV != first.end(); ++thisV, ++otherV) {
      //this comparison is costly, so I'm using this unelegant expression to minimize the calls to it.
      if (lessThen(*thisV , *otherV))
        return true;
      if (lessThen(*otherV , *thisV))
        return false;
    }

    //they are the same
    return false;

  }
    
};

//assumes fluents are in the same order. 
//equals if everything else than timestep is equal.
struct stateEquals {

  stateEquals(const std::set<AspFluent>& state) : state(state) {}

  bool operator()(const std::set<AspFluent>& otherstate) const;

  std::set<AspFluent> state;
};  


}

#endif