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/*
 * SimMetrics - SimMetrics is a java library of Similarity or Distance Metrics,
 * e.g. Levenshtein Distance, that provide float based similarity measures
 * between String Data. All metrics return consistent measures rather than
 * unbounded similarity scores.
 * 
 * Copyright (C) 2014 SimMetrics authors
 * 
 * This file is part of SimMetrics. This program 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.
 * 
 * This program 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
 * SimMetrics. If not, see .
 */

package org.simmetrics.simplifiers;

import java.text.Normalizer;
import java.util.regex.Pattern;

/**
 * Removes non-diacritics with a regular expression. Character ranges relevant
 * for simplification. See Pattern Matching
 * - Character Classes
 * 
 * \p{InCombiningDiacriticalMarks}\p{IsLm}\p{IsSk}]+
 * 

 * 
 * 

 * InCombiningDiacriticalMarks: special marks that are part of "normal" ä,
 * ö, î etc..
 * 
 * 
IsSk:
 * Symbol, Modifier
 * 
IsLm: Letter, Modifier
 * 
 * 
 *
 * 
 * This class is thread-safe and immutable.
 * 
 *
 */
public class NonDiacritics implements Simplifier {

	@Override
	public String simplify(String input) {
		return DIACRITICS_AND_FRIENDS.matcher(
				Normalizer.normalize(input, Normalizer.Form.NFD))
				.replaceAll("");
	}

	private static final Pattern DIACRITICS_AND_FRIENDS = Pattern
			.compile("[\\p{InCombiningDiacriticalMarks}\\p{IsLm}\\p{IsSk}]+");

	@Override
	public String toString() {
		return "NonDiacritics";
	}

}