BindLink.h

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/*
 * opencog/atoms/BindLink.h
 *
 * Copyright (C) 2015 Linas Vepstas
 * All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License v3 as
 * published by the Free Software Foundation and including the exceptions
 * at http://opencog.org/wiki/Licenses
 *
 * This program 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 Affero General Public License
 * along with this program; if not, write to:
 * Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef _OPENCOG_BIND_LINK_H
#define _OPENCOG_BIND_LINK_H

#include <opencog/atoms/bind/PatternLink.h>

namespace opencog
{
class BindLink : public PatternLink
{
protected:
    void init(void);

    Handle _implicand;

    // Overwrite PatternLink::extract_variables as BindLink has one
    // more outgoing for the rewrite rule. In addition this method
    // will initialize the rewrite term _implicand.
    void extract_variables(const HandleSeq& oset);

    BindLink(Type, const HandleSeq&,
             TruthValuePtr tv = TruthValue::DEFAULT_TV(),
             AttentionValuePtr av = AttentionValue::DEFAULT_AV());

public:
    BindLink(const HandleSeq&,
             TruthValuePtr tv = TruthValue::DEFAULT_TV(),
             AttentionValuePtr av = AttentionValue::DEFAULT_AV());

    BindLink(Link &l);

    bool imply(PatternMatchCallback&, bool check_connectivity=true);
    const Handle& get_implicand(void) { return _implicand; }
};

typedef std::shared_ptr<BindLink> BindLinkPtr;
static inline BindLinkPtr BindLinkCast(const Handle& h)
    { AtomPtr a(h); return std::dynamic_pointer_cast<BindLink>(a); }
static inline BindLinkPtr BindLinkCast(AtomPtr a)
    { return std::dynamic_pointer_cast<BindLink>(a); }

// XXX temporary hack ...
#define createBindLink std::make_shared<BindLink>

}

#endif // _OPENCOG_BIND_LINK_H