/*
* Redberry: symbolic tensor computations.
*
* Copyright (c) 2010-2014:
* 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.core.transformations.substitutions;
import cc.redberry.core.indexmapping.Mapping;
import cc.redberry.core.tensor.SumBuilder;
import cc.redberry.core.tensor.Tensor;
import java.util.Arrays;
/**
* @author Dmitry Bolotin
* @author Stanislav Poslavsky
*/
class PrimitiveSumSubstitution extends PrimitiveSubstitution {
public PrimitiveSumSubstitution(Tensor from, Tensor to) {
super(from, to);
}
@Override
Tensor newTo_(Tensor current, SubstitutionIterator iterator) {
Tensor old = null;
while (old != current) {
old = current;
SumBijectionPort.BijectionContainer bc = new SumBijectionPort(from, current).take();
if (bc == null)
return current;
Mapping mapping = bc.mapping;
Tensor newTo = applyIndexMappingToTo(current, to, mapping, iterator);
SumBuilder builder = new SumBuilder();
int[] bijection = bc.bijection;
builder.put(newTo);
Arrays.sort(bijection);
int pivot = 0;
for (int i = 0, size = current.size(); i < size; ++i) {
if (pivot >= bijection.length || i != bijection[pivot])
builder.put(current.get(i));
else
++pivot;
}
current = builder.build();
}
return current;
}
}