/*
* 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.utils.OutputPort;
import cc.redberry.core.combinatorics.IntDistinctTuplesPort;
import cc.redberry.core.tensor.Tensor;
import cc.redberry.core.utils.IntArrayList;
/**
* @author Dmitry Bolotin
* @author Stanislav Poslavsky
*/
final class IndexlessBijectionsPort implements OutputPort<int[]> {
private boolean finished = false;
private final IntDistinctTuplesPort combinationsPort;
public IndexlessBijectionsPort(final Tensor[] from, final Tensor[] to) {
if (from.length > to.length) {
finished = true;
combinationsPort = null;
return;
}
IntArrayList[] hashReflections = new IntArrayList[from.length];
int i, j, hash;
for (i = 0; i < from.length; ++i) {
hashReflections[i] = new IntArrayList();
hash = from[i].hashCode();
for (j = 0; j < to.length; ++j)
if (to[j].hashCode() >= hash)
break;
if (j == to.length || to[j].hashCode() > hash) {
finished = true;
break;
}
for (; j < to.length; ++j) {
if (to[j].hashCode() != hash)//TODO add mappings check
break;
hashReflections[i].add(j);
}
}
if (finished) {
combinationsPort = null;
return;
}
int[][] r = new int[from.length][];
for (i = 0; i < from.length; ++i)
r[i] = hashReflections[i].toArray();
combinationsPort = new IntDistinctTuplesPort(r);
}
@Override
public int[] take() {
if (finished)
return null;
return combinationsPort.take();
}
}