package ca.pfv.spmf.algorithms.sequentialpatterns.clasp_AGP.dataStructures.patterns;
import java.util.ArrayList;
import java.util.List;
import ca.pfv.spmf.algorithms.sequentialpatterns.clasp_AGP.dataStructures.abstracciones.ItemAbstractionPair;
/**
* This class is the implementation of a creator of patterns.
* By means this class, different kind of patterns can be used for this algorithm.
*
* Copyright Antonio Gomariz PeƱalver 2013
*
* This file is part of the SPMF DATA MINING SOFTWARE
* (http://www.philippe-fournier-viger.com/spmf).
*
* SPMF 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.
*
* SPMF 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 SPMF. If not, see <http://www.gnu.org/licenses/>.
*
* @author agomariz
*/
public class PatternCreator {
private static PatternCreator instance = null;
public static void sclear() {
instance=null;
}
private PatternCreator() {
}
public static PatternCreator getInstance() {
if (instance == null) {
instance = new PatternCreator();
}
return instance;
}
/**
* It creates a pattern from a list of pairs of the form <abstraction, item>.
* @param elements a list of pairs
* @return the resulting pattern
*/
public Pattern createPattern(List<ItemAbstractionPair> elements) {
Pattern newPattern;
if (elements == null) {
newPattern = new Pattern();
} else {
newPattern = new Pattern(elements);
}
return newPattern;
}
/**
* It creates a pattern of only one item.
* @param pair the pair to be used to create the pattern
* @return the resulting pattern
*/
public Pattern createPattern(ItemAbstractionPair pair) {
List<ItemAbstractionPair> elements = new ArrayList<ItemAbstractionPair>();
elements.add(pair);
return createPattern(elements);
}
/**
* It creates an empty pattern
* @return the resulting pattern
*/
public Pattern createPattern() {
List<ItemAbstractionPair> pairList = null;
return createPattern(pairList);
}
/**
* It concatenates a pair to the given pattern
* @param p1 pattern where the pair has to be concatenated
* @param pair pair to concatenate with the pattern given as parameter
* @return the resulting pattern
*/
public Pattern concatenate(Pattern p1, ItemAbstractionPair pair) {
if (p1 == null) {
if (pair == null) {
return null;
}
return createPattern(pair);
}
if (pair == null) {
return p1;
}
return p1.concatenate(pair);
}
}