TypeNode.h

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/*
 * opencog/atoms/TypeNode.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_TYPE_NODE_H
#define _OPENCOG_TYPE_NODE_H

#include <opencog/atomspace/AtomSpace.h>
#include <opencog/atomspace/ClassServer.h>
#include <opencog/atomspace/Node.h>

namespace opencog
{
class TypeNode : public Node
{
protected:
    Type value;

public:
    TypeNode(const std::string& s,
               TruthValuePtr tv = TruthValue::DEFAULT_TV(),
               AttentionValuePtr av = AttentionValue::DEFAULT_AV())
        // Convert to number and back to string to avoid miscompares.
        : Node(TYPE_NODE, s, tv, av),
          value(classserver().getType(s))
    {
        if (NOTYPE == value)
            throw InvalidParamException(TRACE_INFO,
                "Not a valid typename: '%s'", s.c_str());
    }

    TypeNode(Type t,
               TruthValuePtr tv = TruthValue::DEFAULT_TV(),
               AttentionValuePtr av = AttentionValue::DEFAULT_AV())
        : Node(TYPE_NODE, classserver().getTypeName(t), tv, av),
          value(t)
    {}

    TypeNode(Node &n)
        : Node(n),
          value(classserver().getType(n.getName()))
    {
        OC_ASSERT(TYPE_NODE == n.getType(), "Bad TypeNode constructor!");

        if (NOTYPE == value)
            throw InvalidParamException(TRACE_INFO,
                "Not a valid typename: '%s'", n.getName().c_str());
    }

    static void validate(const std::string& str)
    {
        Type t = classserver().getType(str);
        if (NOTYPE == t)
            throw InvalidParamException(TRACE_INFO,
                "Not a valid typename: '%s'", str.c_str());
    }

    Type get_value(void) { return value; }
};

typedef std::shared_ptr<TypeNode> TypeNodePtr;
static inline TypeNodePtr TypeNodeCast(const Handle& h)
    { AtomPtr a(h); return std::dynamic_pointer_cast<TypeNode>(a); }
static inline TypeNodePtr TypeNodeCast(AtomPtr a)
    { return std::dynamic_pointer_cast<TypeNode>(a); }

// XXX temporary hack ...
#define createTypeNode std::make_shared<TypeNode>

}

#endif // _OPENCOG_TYPE_NODE_H