module demo;
import java.io.*;

/* TrapWorker.salsa -- 
 *   Worker for Parallel Trapezoidal Rule
 */

behavior TrapWorker{
  Double trap(Double local_a ,Double local_b,Integer local_n ,Double h) {
    //integral = (f(local_a) + f(local_b))/2.0;
    token f_local_a = f(local_a);
    token f_local_b = f(local_b);
    token integral = startIntegral(f_local_a, f_local_b);
    double x = local_a.doubleValue();

    for (int i = 1; i <= local_n.intValue()-1; i++, x+=h.doubleValue()) {
      //x = add(x,h);
      token f_x = f(new Double(x));
      integral = add(integral, f_x);     //x = x + h; integral = integral + f(x);
    }

    multiply(integral, h)@currentContinuation;
}


Double f(Double d) {           
    double dv = d.doubleValue();
     return new Double(5*dv*dv*dv*dv);
}


Double add(Double d, Double f){           
    double dv = d.doubleValue();
    double fv = f.doubleValue();
    return new Double(dv+fv);
} 

 

Double multiply(Double d, Double f){
    double dv = d.doubleValue();
    double fv = f.doubleValue();
    return new Double(dv*fv);
}

 

Double startIntegral(Double d, Double f){
    return new Double((d.doubleValue()+f.doubleValue())/2.0);
}

}