InvertibleRestFunction.java

/*
 * Vitry, copyright (C) Hans Hoglund 2011
 * 
 * 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 3 of the License, or
 * at your option) any later version.
 * 
 * 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, see <http://www.gnu.org/licenses/>.
 *
 * See COPYING.txt for details.
 */
package vitry.runtime;

import vitry.runtime.error.*;
import vitry.runtime.struct.*;


public class InvertibleRestFunction extends RestFunction implements InvertibleFunction
{
    public Seq<?> applyVarInverse(Object a) throws InvocationError
    {
        throw new NoImplementationException();
    }

    public InvertibleRestFunction getInverse()
    {
        return new Inv();
    }

    public Object applyInverse(Object a) throws InvocationError
    {
        return applyVarInverse(Seqs.single(a));
    }

    public boolean isInvertible()
    {
        return true;
    }

    private final class Inv extends InvertibleRestFunction
    {
        public Object apply(Object a) throws InvocationError
        {
            return InvertibleRestFunction.this.applyInverse(a);
        }

        public Object applyInverse(Object a) throws InvocationError
        {
            return InvertibleRestFunction.this.apply(a);
        }

        public Object applyVar(Seq<?> args)
        {
            return InvertibleRestFunction.this.applyVarInverse(args.head()).head();
        }

        public Seq<Object> applyVarInverse(Object a) throws InvocationError
        {
            return Seqs.single(InvertibleRestFunction.this.applyVar(Seqs.single(a)));
        }
    }
}