/**
* 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 com.rapidminer.tools.expression.FunctionDescription;
import com.rapidminer.tools.expression.internal.function.AbstractArbitraryStringInputStringOutputFunction;
/**
* A {@link Function} for concatenating Strings.
*
* @author David Arnu
*
*/
public class Concat extends AbstractArbitraryStringInputStringOutputFunction {
/**
* Creates a function for concatenating Strings.
*/
public Concat() {
super("text_transformation.concat", FunctionDescription.UNFIXED_NUMBER_OF_ARGUMENTS);
}
@Override
protected String compute(String... values) {
StringBuilder builder = new StringBuilder();
for (String value : values) {
// missing values are ignored
if (value != null) {
builder.append(value);
}
}
return builder.toString();
}
@Override
protected void checkNumberOfInputs(int length) {
// we do not care about the number of attributes
}
}