C311 Spring 1997 -- Programming Languages

Assignment 11: Closures in Java

Due Sunday, April 27, 11:59pm

Translate the following program using higher-order functions into Java using the method presented in class and Script 12.

import java.util.Vector;
import java.util.Enumeration;

class MapVector extends Vector {
  MapVector map((Object) -> Object f) {
    MapVector newMV = new MapVector();
    for (Enumeration e = this.elements() ; e.hasMoreElements() ;) {
      newMV.addElement(f(e.nextElement()));
    }
    return newMV;
  }
}
public class TestMapVector {
  (Object) -> Object curryConcat(String s1) {
    return fun (Object s2) -> Object {
      return (Object)(s1 + (String)s2);
    }
  }  
  public static void main(String[] args) {
    MapVector things = new MapVector();
    TestMapVector tester = new TestMapVector();
    things.addElement("one");
    things.addElement("two");
    things.addElement("three");
    MapVector mv = things.map(tester.curryConcat("plus "));
    System.out.println(mv);
  }
}
      

Submission

As before, but refer to "handin 11". However, this assignment won't be automatically graded.