/*
* RapidMiner
*
* Copyright (C) 2001-2011 by Rapid-I and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapid-i.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.math.function.expressions.text;
import java.util.Stack;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.nfunk.jep.ParseException;
import org.nfunk.jep.function.PostfixMathCommand;
import com.rapidminer.tools.math.function.UnknownValue;
/**
* Returns true if and only if the given expression can be find in the given text.
*
* @author Ingo Mierswa
*/
public class Finds extends PostfixMathCommand {
public Finds() {
numberOfParameters = 2;
}
@SuppressWarnings("unchecked")
@Override
public void run(Stack stack) throws ParseException {
checkStack(stack);// check the stack
// initialize the result to the first argument
Object expressionObject = stack.pop();
Object textObject = stack.pop();
// checking for unknown value
if (expressionObject == UnknownValue.UNKNOWN_NOMINAL || textObject == UnknownValue.UNKNOWN_NOMINAL) {
stack.push(UnknownValue.UNKNOWN_BOOLEAN);
return;
}
if (!(textObject instanceof String) || !(expressionObject instanceof String)) {
throw new ParseException("Invalid argument types, must be (string, string)");
}
String text = (String) textObject;
String expression = (String) expressionObject;
Pattern p = Pattern.compile(expression);
Matcher m = p.matcher(text);
stack.push(m.find());
}
}