QueryTree.h

Go to the documentation of this file.

/*
 * This file is part of KnowRob, please consult
 * https://github.com/knowrob/knowrob for license details.
 */
 
#ifndef KNOWROB_QUERY_TREE_H
#define KNOWROB_QUERY_TREE_H
 
#include <memory>
#include <list>
#include "knowrob/formulas/Formula.h"
#include "knowrob/formulas/Predicate.h"
#include "knowrob/formulas/Conjunction.h"
#include "knowrob/formulas/Disjunction.h"
#include "knowrob/formulas/Implication.h"
#include "knowrob/formulas/Negation.h"
#include "knowrob/formulas/ModalFormula.h"
#include "knowrob/formulas/FirstOrderLiteral.h"
 
namespace knowrob {
    class QueryTree {
    public:
        explicit QueryTree(const FormulaPtr &query);
 
        ~QueryTree();
 
        QueryTree(const QueryTree &) = delete;
 
        auto numPaths() const { return paths_.size(); }
 
        const auto &paths() const { return paths_; }
 
        auto begin() const { return paths_.begin(); }
 
        auto end() const { return paths_.end(); }
 
        class Node {
        public:
            Node(Node *parent, FormulaPtr formula, bool isNegated);
 
            Node *parent;
            const FormulaPtr formula;
            bool isNegated;
            bool isOpen;
            std::list<Node *> successors;
 
            int priority() const;
        };
 
        class Path {
        public:
            Path() = default;
 
            auto numNodes() const { return nodes_.size(); }
 
            const auto &nodes() const { return nodes_; }
 
            auto begin() const { return nodes_.begin(); }
 
            auto end() const { return nodes_.end(); }
 
            std::shared_ptr<Formula> toFormula() const;
 
        protected:
            std::vector<FormulaPtr> nodes_;
 
            friend class QueryTree;
        };
 
    protected:
        const FormulaPtr query_;
        std::list<Path> paths_;
 
        Node *rootNode_;
 
        struct NodeComparator {
            bool operator()(const Node *a, const Node *b) const;
        };
 
        std::priority_queue<Node *, std::vector<Node *>, NodeComparator> openNodes_;
 
        Node *createNode(Node *parent, const FormulaPtr &phi, bool isNegated);
 
        static std::list<QueryTree::Node *> getLeafs(Node *n);
 
        static bool hasCompletePath(Node *leaf);
 
        static void constructPath(Node *leaf, Path &path);
 
        void expandNextNode();
    };
 
} // knowrob
 
#endif //KNOWROB_QUERY_TREE_H