fr.univnantes.termsuite.utils.CollectionUtils Maven / Gradle / Ivy
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* Copyright 2015-2016 - CNRS (Centre National de Recherche Scientifique)
*
* Licensed to the Apache Software Foundation (ASF) under one
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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package fr.univnantes.termsuite.utils;
import java.util.List;
import java.util.Set;
import com.google.common.collect.Sets;
public class CollectionUtils {
/**
*
* Transforms a list of sets into a set of element pairs,
* which is the union of all cartesian products of
* all pairs of sets.
*
* Example:
*
* A = {a,b,c}
* B = {d}
* C = {e, f}
*
* returns AxB U AxC U BxC = {
* {a,d}, {b,d}, {c,d},
* {a,e}, {a,f}, {b,e}, {b,f}, {c,e}, {c,f},
* {d,e}, {d,f}
* }
*
*
* @param iterable
* @return
*/
@SuppressWarnings("unchecked")
public static > Set> combineAndProduct(List> sets) {
Set> results = Sets.newHashSet();
for(int i = 0; i< sets.size(); i++) {
for(int j = i+1; j< sets.size(); j++)
for(List l:Sets.cartesianProduct(sets.get(i), sets.get(j)))
results.add(new Pair(l.get(0), l.get(1)));
}
return results;
}
}