/*
// $Id: //open/dev/farrago/src/org/eigenbase/oj/rex/OJRexImplementor.java#9 $
// Package org.eigenbase is a class library of data management components.
// Copyright (C) 2005-2009 The Eigenbase Project
// Copyright (C) 2002-2009 SQLstream, Inc.
// Copyright (C) 2005-2009 LucidEra, Inc.
// Portions Copyright (C) 2003-2009 John V. Sichi
//
// This program 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 2 of the License, or (at your option)
// any later version approved by The Eigenbase Project.
//
// 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 General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
package org.eigenbase.oj.rex;

import openjava.ptree.*;

import org.eigenbase.rex.*;


/**
 * OJRexImplementor translates a call to a particular operator to OpenJava code.
 *
 * <p>Implementors are held in a {@link OJRexImplementorTable}.
 *
 * @author John V. Sichi
 * @version $Id: //open/dev/farrago/src/org/eigenbase/oj/rex/OJRexImplementor.java#9 $
 */
public interface OJRexImplementor
{
    //~ Methods ----------------------------------------------------------------

    /**
     * Implements a single {@link RexCall}.
     *
     * @param translator provides translation context
     * @param call the call to be translated
     * @param operands call's operands, which have already been translated
     * independently
     */
    public Expression implement(
        RexToOJTranslator translator,
        RexCall call,
        Expression [] operands);

    /**
     * Tests whether it is possible to implement a call.
     *
     * @param call the call for which translation is being considered
     *
     * @return whether the call can be implemented
     */
    public boolean canImplement(RexCall call);
}

// End OJRexImplementor.java
