/**
* Copyright (C) 2001-2017 by RapidMiner and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapidminer.com
*
* This program is free software: you can redistribute it and/or modify it under the terms of the
* GNU Affero 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
* Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License along with this program.
* If not, see http://www.gnu.org/licenses/.
*/
package com.rapidminer.tools.expression.internal.function.text;
import java.util.Locale;
import com.rapidminer.tools.expression.Function;
import com.rapidminer.tools.expression.FunctionInputException;
import com.rapidminer.tools.expression.internal.function.AbstractArbitraryStringInputStringOutputFunction;
/**
* A {@link Function} which transforms a nominal value to its lower case representation.
*
* @author Thilo Kamradt
*
*/
public class Lower extends AbstractArbitraryStringInputStringOutputFunction {
/**
* Creates a function that transforms a nominal value to its lower case representation
*/
public Lower() {
super("text_transformation.lower", 1);
}
@Override
protected String compute(String... values) {
if (values[0] == null) {
return null;
}
return values[0].toLowerCase(Locale.ENGLISH);
}
@Override
protected void checkNumberOfInputs(int length) {
if (length != 1) {
throw new FunctionInputException("expression_parser.function_wrong_input", getFunctionName(), 1, length);
}
}
}