/*
* Redberry: symbolic tensor computations.
*
* Copyright (c) 2010-2012:
* Stanislav Poslavsky <stvlpos@mail.ru>
* Bolotin Dmitriy <bolotin.dmitriy@gmail.com>
*
* This file is part of Redberry.
*
* Redberry 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.
*
* Redberry 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 Redberry. If not, see <http://www.gnu.org/licenses/>.
*/
package cc.redberry.transformation;
import cc.redberry.core.tensor.Tensor;
import cc.redberry.core.tensor.TensorIterator;
import cc.redberry.core.tensor.iterators.GuidePermit;
import cc.redberry.core.tensor.iterators.IterationGuide;
/**
*
* @author Dmitry Bolotin
* @author Stanislav Poslavsky
*/
public abstract class NativeReccursionTransformation<T> {
private final IterationGuide guide;
public NativeReccursionTransformation(IterationGuide guide) {
this.guide = guide;
}
protected void innerTransform(Tensor tensor, T parameter) {
TensorIterator it = tensor.iterator();
Tensor t, newT;
while (it.hasNext()) {
t = it.next();
//TODO diskuss
if (guide.letInside(it, t) != GuidePermit.Enter)
continue;
newT = transform(t, preprocessParameter(parameter, it));
if (newT == null) {
it.remove();
continue;
}
if (newT != t)
it.set(newT);
}
}
protected T preprocessParameter(T parameter, TensorIterator info) {
return parameter;
}
protected abstract Tensor transform(Tensor tensor, T parameter);
}