/*
* 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.fraction;
import java.util.ArrayList;
import java.util.List;
import cc.redberry.core.tensor.Fraction;
import cc.redberry.core.tensor.Product;
import cc.redberry.core.tensor.Tensor;
import cc.redberry.core.tensor.TensorIterator;
import cc.redberry.transformation.Transformation;
/**
*
* @author Dmitry Bolotin
* @author Stanislav Poslavsky
* @author Konstantin Kiselev
*/
public class MultiplyFractions implements Transformation {
@Override
public Tensor transform(Tensor tensor) {
if (!(tensor instanceof Product))
return tensor;
List<Tensor> denominators = new ArrayList<>();
TensorIterator iterator = tensor.iterator();
Tensor current;
while (iterator.hasNext()) {
current = iterator.next();
if (current instanceof Fraction) {
Fraction frac = (Fraction) current;
iterator.set(frac.getNumerator());
denominators.add(frac.getDenominator());
}
}
if (denominators.isEmpty())
return tensor;
//TODO run with RemmoveOneFromProduct transformation
return new Fraction(tensor, denominators.size() == 1 ? denominators.get(0) : new Product(denominators));
}
}