CutString.java

package functions.custom;

import java.util.Set;

import ca.uqac.lif.cep.Context;
import ca.uqac.lif.cep.EventTracker;
import ca.uqac.lif.cep.functions.Function;

public class CutString extends Function
{
    public void evaluate(Object[] inputs, Object[] outputs, Context c, EventTracker t) {
        outputs[0] = ((String) inputs[0]).substring(0, 
            (Integer) inputs[1]);
    }

    public int getInputArity() {
        return 2;
    }

    public int getOutputArity() {
        return 1;
    }
    
    public Function duplicate(boolean with_state) {
        return new CutString();
    }

    public void getInputTypesFor(Set<Class<?>> s, int i) {
        if (i == 0)
            s.add(String.class);
        if (i == 1)
            s.add(Number.class);
    }

    public Class<?> getOutputTypeFor(int i) {
        if (i == 0)
            return String.class;
        return null;
    }
}