vs10/term.h

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// Copyright (c) 2009, Roland Kaminski <kaminski@cs.uni-potsdam.de>
//
// This file is part of gringo.
//
// gringo is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// gringo is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with gringo.  If not, see <http://www.gnu.org/licenses/>.

#pragma once

#include <gringo/gringo.h>
#include <gringo/locateable.h>

class Term : public Locateable
{
public:
    typedef std::pair<Term*, TermPtrVec*> Split;
    class Ref
    {
    public:
        virtual void reset(Term *a) const = 0;
        virtual void replace(Term *a) const = 0;
        virtual ~Ref() { }
    };
    class VecRef : public Ref
    {
    public:
        VecRef(TermPtrVec &vec, TermPtrVec::iterator pos) : vec_(vec), pos_(pos) { }
        void reset(Term *a) const { vec_.replace(pos_, a); }
        void replace(Term *a) const { vec_.replace(pos_, a).release(); }
    private:
        TermPtrVec          &vec_;
        TermPtrVec::iterator pos_;
    };
    class PtrRef : public Ref
    {
    public:
        PtrRef(clone_ptr<Term> &ptr) : ptr_(ptr) { }
        void reset(Term *a) const { ptr_.reset(a); }
        void replace(Term *a) const { ptr_.release(); ptr_.reset(a); }
    private:
        clone_ptr<Term> &ptr_;
    };
public:
    Term(const Loc &loc) : Locateable(loc) { }
    virtual Val val(Grounder *grounder) const = 0;
    virtual Split split() { return Split( (Term*)0, (TermPtrVec*)0); }
    virtual void normalize(Lit *parent, const Ref &ref, Grounder *g, Expander *expander, bool unify) = 0;
    virtual bool unify(Grounder *grounder, const Val &v, int binder) const = 0;
    virtual void vars(VarSet &v) const = 0;
    virtual void visit(PrgVisitor *visitor, bool bind) = 0;
    virtual bool constant() const = 0;
    virtual void print(Storage *sto, std::ostream &out) const = 0;
    virtual Term *clone() const = 0;
    virtual ~Term() { }
};

namespace boost
{
    template <>
    inline Term* new_clone(const Term& a)
    {
        return a.clone();
    }
}