CS 3500   Spring 2010
Object-Oriented Design

 

Overview

Official summary: The course presents the theory and practice of object-oriented programming. The course enhances students understanding of the concepts of object, class, message, method, inheritance, and genericity. The course covers a basic model for objects; the principles of types and polymorphism in object-oriented programming languages; different forms of abstraction; and theory and practice of reuse. The course also introduces students to some object-oriented design patterns that practitioners have found useful.

 

Announcements   [RSS]

Wed, 21 Apr 2010: Here is my updated final exam information. First, from the registrar's office, the exam is Monday, April 26th, 8:00-10:00, in Robinson Hall 409. The format of the final will be that of the midterm, so half "theoretical" questions and half "practical" questions. Just like the midterm, you have the right to a double-sided 8.5"x11" cheat sheet. Other than that, closed books and closed notes and closed computers.

Wed, 21 Apr 2010: Here are the Submission Instructions for Homework 6 --

(1) Write a README text file giving your team members, and describing the extensions to the game you have made: what extensions you made, what classes you added, interesting bits about implementation of those classes, even a sample execution of the game showcasing your extensions to the game.

(2) Zip up all the source code of your game, as well as your README file, into a file called homework6.zip. The idea is that I should be able to compile your whole game using your submitted file, without messing with it.

(3) Go to the submission site and submit your zip file. Only one submission per team is necessary.

Tue, 20 Apr 2010: Here is the final review list from this morning's lecture. This morning, I also talked about abstracting control-flow, and gave a continuations-based example in Scheme. Here is an interesting and short article that highlights continuations in Scheme and shows how to use them to implement other control-flow mechanisms, such as exceptions, and time-traveling search, among others. I mentioned that continuations were useful to understand web programs; the following article gives a sense of what I mean. For the more technically inclined, you may find the following article interesting.

Fri, 16 Apr 2010: Here is a link to a decent Python tutorial. I've uploaded the code from this morning's lecture, List.py, as well as a sample session with the code, a bit different in the details from what I did this morning, but similar in spirit.

Fri, 09 Apr 2010: Lecture notes for this morning's lecture on the Model-View-Controller design pattern are now available. I also provided the source code for the lecture.

Tue, 06 Apr 2010: I'm canceling class and office hourse today, seeing I lost my voice because of a cold. I'll hold make-up office hours this Friday, 15h00-17h00.

Mon, 05 Apr 2010: A quick look at Banner seems to indicate the following time for our final exam: 8:00am - 10:00am M Apr 26, 2010 .

Sun, 04 Apr 2010: A bit late because of the flu, but homework 6 is up. Due Sunday, April 25th. There is a lot of support code for this one.

Sat, 03 Apr 2010: Lecture notes for Friday's lecture on the Publish-Subscribe design pattern are now available. I also provided the source code for the lecture.

Wed, 31 Mar 2010: Notes for Tuesday's lecture on the interaction of subclassing and mutation are now available.

Fri, 26 Mar 2010: Notes for this morning's lecture on adapters are now available.

Thu, 25 Mar 2010: In the specification of MovieB in Question 3, the signature of the numberFrames() method should indicate it returns an Option<Integer>, and not an int. The code gets this right.

Tue, 23 Mar 2010: Lecture notes for this morning's lecture on mutation are now up.

Tue, 23 Mar 2010: A student just pointed out to me that my description of behaviors is missing something important. Intuitively, the scale(str) behavior takes a streams str of floats and produces (via an iterator) a sequence of transformations that scale a frame around its center by the specified ratio, using the scale() operation on frames. The rotate(str) behavior takes a stream str of floats and produces a sequence of transformations that rotate a frame around its center by the specified degrees, using the rotate() operation on frames. I've updated the homework write-up.

Tue, 23 Mar 2010: Here are a couple of sample files for testing your homework 5 code. First, to try out your MFrameB implementation, here's TestMFrameB.java, that has a couple of sample frames to try out your translate, rotate, and scale functions, independently, and all together. Pick one of the four tests (comment out the others, only the last one will actually show), and try it out. Here are the outputs that testTranslate(), testRotate(), testScale(), and testAll create, respectively:

To try out your behaviors and movies, use TestMovieB.java, which constructs three behaviors (a cross movement behavior, a spinning-in-place behavior, and a smaller-then-bigger behavior) and applies them to the boy sprite. Again, there are four tests available, choose one and comment the others. (Otherwise, only the first one will actually run.)

Sat, 20 Mar 2010: Lecture notes for Friday's lecture on multiple inheritance and ADT extension are now up. Let me know if anything is amiss.

Mon, 17 Mar 2010: Homework 5 is up. Due Friday, March 26th. There are a bunch of support files available for this homework.

Tue, 16 Mar 2010: In case you're waiting with bated breath, I'm still hacking on homework 5, and I expect to get it out tomorrow morning.

Tue, 16 Mar 2010: Lecture notes for this morning's lecture on inheritance and delegation are now up. They're a bit rough around the edges, so let me know if anything doesn't actually make sense in there.

Fri, 12 Mar 2010: Lecture notes for this morning's lecture on laziness are now up. I also provided the source code for the lecture.

Fri, 12 Mar 2010: A couple of comments about homework 4, due tonight. First off, some people spotted the fact that the specification for Overlay(m1,m2).funcIterator().moveToNext() in Question 3 is missing. Indeed. Oversight on my part. Here's what moveToNext() should do: it should move both of the underyling iterators for m1 and m2 to the next element, leaving either one unmoved if it's out of elements.

Second, the implementation of equals() for Question 1 is headachy because Option is a polymorphic class. Rather than having you figure it out yourself, here is the implementation of equals() for both concrete subclasses of Option. For none():

   public boolean equals (Object obj) {
       if (obj instanceof Option) {
           @SuppressWarnings("unchecked")
           Option foo = (Option) obj;
           return foo.isNone();
       }
       return false;
   }

  

And for some():
  


   public boolean equals (Object obj) {
       if (obj instanceof Option) {
           @SuppressWarnings("unchecked")
           Option foo = (Option) obj;
           return (!foo.isNone() && foo.valOf().equals(this.value));
       }
       return false;
   }






Thu, 11 Mar 2010: Some of you have asked for a couple of sample movies for trying out
your code for homework 4. Here's one,  MovingBoys.java,
that creates a movie made up of the overlay of three smaller movies
that move a simple sprite in the canvas window.Here
are the three snapshots from the movie:
  









Thu, 11 Mar 2010: Lecture notes for Tuesday's lecture on the Map and Reduce design
patterns are
now 
up. 
I also provided the
source
code for the lecture. 





Tue, 09 Mar 2010: Midterm results posted to Blackboard, and were distributed in class
this morning. If you missed yours, I'll try to remember to bring it in
on Friday. And I wasn't too far off: the average on the midterm was
41.31, with a standard deviation of 6.56.





Sat, 06 Mar 2010: Than reports a small typo in homework 4. It should not cause any
problems, but just in case: The line with public static
Option<Integer> mimimum (List<Integer> lst)  should
define function minimum not mimimum. 





Mon, 01 Mar 2010: Homework 4 is 

up. Due Friday, March 12th. There are a bunch
of support
  files available for 
this homework, including an implementation of the Sprite ADT from
homework 3.





Sat, 27 Feb 2010: Lecture notes for Friday's lecture on functional iterator gadgets are
now 
up. 
I also provided the
source
code for the lecture. 





Wed, 24 Feb 2010: Here is
a list
of topics that you should know for the midterm.  





Tue, 23 Feb 2010: One thing came up in question 2 of homework 3: some of the math asks
you to divide values. 
Because of the way Java is designed, if you try to divide two
integers, the result will be rounded to an integer. Which means that,
if you're not careful, you easily end up with 0s -- for instance, when evaluating 3/5. 
The solution is to cast one of the integers to a float before dividing
(that will force Java to use floating-point division). 
Or, if you prefer, just use the following function div to divide
integers:
  

    public static float div (int i, int j) {

      return ((float) i)/j;

    }





Tue, 23 Feb 2010: First, if you haven't picked up your graded homeworks 1 or 2 yet
they're in a box outside my office, in WVH 328. 
  

Second, extension for homework 3, until Thursday night, 22h00. 
  

Finally, we have a midterm this coming Friday, in class. Closed-books
exam, but I'll let you bring in a single double-sided 8.5x11 crib
sheet. The exam covers everything we've seen in the semester. I'll
post a broken down list of things to be sure to know later
today. Watch this space.





Mon, 22 Feb 2010: Some of you are crunching hard on homework 3, and having some
difficulty with question 2, on the Picture ADT. Well, it is a bit
subtle. So here's a suggestion. First off, identify the creators of
the ADT, and follow the Specification Design Pattern (see lecture 7). 
Don't implement the drawIterator() operation just
yet. Implement the following operation instead, one that counts the
number of lines in a picture: here is the signature of the
operation:
  

   public int countLines ();
  

with the following specification:
  

   nil().countLines() = 0
  

   sprite(sp).countLines() = countElements(sp.funcIterator())
  

   flip(p).countLines() = p.countLines()
  

   rot(p).countLines() = p.countLines()
  

   overlay(p).countLines() = 2*p.countLines()
  

   beside(n,p,m,q).countLines() = p.countLines()+q.countLines()
  

   above(n,p,m,q).countLines() = p.countLines()+q.countLines()
  

where countElements() is the function that counts the number
of elements from an iterator that we saw in class and in the notes
(suitably modified to work with FuncIteratorLine) -- you can
just make it a private function in the class you're writing, as a
helper function. If you can get the Picture ADT going with the above
operation and without the drawIterator() operation, then
you're in very good shape. You can just focus on the
drawIterator() bit after. 
  

You don't have to do any of the above, of course. This is just to help
you. 





Mon, 22 Feb 2010: Jonathan pointed out that I messed up in my last posted
file MainMan.java -- my code 
used FuncIterator<Line> instead of
FuncIteratorLine, since I told you not to worry about
polymorphism for this homework. The file has now been corrected, and
the web site should have refreshed. If for some reason the change does
not propagate fast enough, you can just replace all instances of 
FuncIterator<Line> by
FuncIteratorLine in the file, by hand.





Mon, 22 Feb 2010: Here are a couple of files implementing some sample pictures for you
to try out your
code. First, MainMan.java,
that creates three pictures and displays them in the canvas. (You need
to click the canvas to move to the next picture. See the code.) Here
are the three pictures you should see:
  




  

Second, MainArrow.java,
that also creates three pictures and displays them in the canvas. (And
again you need 
to click the canvas to move to the next picture. See the code.) Here
are the three pictures you should see:
  









Sat, 20 Feb 2010: Final version of the lecture notes for Friday's lecture are now
up. I've
added the bit about polymorphic pairs and polymorphic addable pairs,
stuff that I did not have time to do in class. I also provided the
source code for the lecture.





Sat, 20 Feb 2010: Lecture notes for Friday's lecture are partially completed and are up. I've
posted them as is, and will complete them probably later tonight or
tomorrow.





Sat, 20 Feb 2010: A few of you spotted the big typo in homework 3: the signature
of drawIterator in the Picture ADT has a
spurious void in it. It should read:
  

public FuncIteratorLine drawIterator (Point, Point, Point);
  

I've updated the write-up (although the refresh rate of the website
seems too low for my taste).





Wed, 17 Feb 2010: Midterm -- we agreed that having the midterm before Spring Break was
a good idea. So that makes the midterm date Friday February 26th, 
during class. It should cover everything until next Tuesday. 
I'll do a quick review on Tuesday. 





Wed, 17 Feb 2010: Lecture notes for yesterday's lecture on polymorphism (aka generics)
are up. I've
also made available a fairly clear tutorial on polymorphism by Bracha,
responsible for the addition of polymorphism to Java. I'll cover
defining polymorphic classes on Friday.





Mon, 15 Feb 2010: Got the following question by email today, the answer will probably be
useful to the lot of you:
  

Since question 1 asks us to submit only one file, should we just 
add the 2 subclass(EmptyFuncIteratorInt & SpriteFuncIteratorInt), but
put the public interface FuncIteratorInt to an other separate file? and
not submitting the interface?
  

The answer is yes, on both counts: (1) put your auxiliary subclasses
for the iterator in the same file as Sprite and (2) put the
public interface FuncIteratorInt in its own file, but don't
submit it. We have our own. (This means of course that you should not
change that interface...)





Fri, 12 Feb 2010: Homework 3 is 

up. Due Tue, 23 Feb. If you go to
the course web
  page you can find the class CanvasWindow that implements
    the window in which you can draw, and reference
    classes Point, Line, and Sprite from
    homeworks 1 and 2 so that you are not penalized if you messed them
    up. 





Fri, 12 Feb 2010: Lecture notes for this morning's lecture on functional iterators are 
up. along
with
the code. Please
note that I've changed the name of the interface for functional
iterators to FuncIteratorInt to emphasize that they're
functional iterators that yield integers. That will avoid name clashes
later on. Homework 3 is coming out later tonight.





Tue, 09 Feb 2010: Lecture notes for this morning's lecture on subclassing from multiple
classes (including Java interfaces)
are up. 





Tue, 09 Feb 2010: In case you forgot it or ditched your email, 
here is the
    submission web site.





Fri, 05 Feb 2010: Lecture notes for Friday's lecture on various topics in subclassing
are up. Includes
both the use of nested classes in the Specification Design Pattern,
and the distinction between compile-time and run-time types, as well
as dynamic dispatch. Sorry it took so long, but I struggled a bit to
try to make things clear. 





Tue, 02 Feb 2010: I distributed graded homeworks 1 this morning. Your grades are
available (as will all subsequent grades) on the course page
on Blackboard. Please make
sure that the grades that are posted actually agree with what you get
back -- I'm counting on you to keep it error-free.





Tue, 02 Feb 2010: Lecture notes for this morning's lecture on code reuse via subclassing
(including the Specification Design Pattern) are up.





Fri, 29 Jan 2010: There we go: lecture notes for this morning's lecture on software
testing are up.





Fri, 29 Jan 2010: Here are the testers
for Line
and Sprite. I
may be playing with them somewhat over the weekend to soften up the
rough edges, so you may want to keep an eye out for updates, announced
here. Okay, next up, lecture notes.





Fri, 29 Jan 2010: Homework 2 is 

up. Due Tue, 09 Feb. I will post the promised testers for
questions 2 and 4 later tonight. Also, you will not be able to answer
question 3 until next week when we see the Specification Design
Pattern, but until then you can do questions 1 and 2.





Tue, 26 Jan 2010: Notes for this morning's lecture on errors and exceptions are

up.





Tue, 26 Jan 2010: If you have not received your registration information for the
submission web site, please send an email to our TA Jon
at jhoag@ccs.neu.edu. 





Mon, 25 Jan 2010: An email was sent to each of you this afternoon containing information
about the submission system and how to register for it. That email was
sent to your HuskyMail account, the one that ends
with husky.neu.edu. Please check it. 





Sat, 23 Jan 2010: Notes for yesterday's lecture on equality for ADTs are

up.





Thu, 21 Jan 2010: Here is a tester that you can use to test your implementation of the
Point ADT for homework 1. Compile it with your code, and run it, it
will test your implementation against the specification, except for
  the equals method, which I will talk about tomorrow. 





Tue, 19 Jan 2010: Notes for this morning's lecture on ADT implementations in Java are

up
,
as well as the code that I used.





Tue, 19 Jan 2010: Homework 1 is 

up
. Due Tue, 26 Jan.





Mon, 18 Jan 2010: Notes for Friday's lecture on ADTs and algebraic specifications are 

up
. 





Wed, 13 Jan 2010: Notes for the introductory lecture yesterday are 

up
. 





Mon, 11 Jan 2010: I'm setting up the RSS feed for the course. You should see an RSS link up
in your browser. And welcome, by the way.





    
 




    
Course Information


    
Time and Location:  Tue/Fri 11:45-13:25
         108 West Village H 
    (#23H)




    
Instructor: Riccardo Pucella,
    328 West Village H (#23H)


    
Office hours: Tue 15:00-17:00


    
Teaching Assistant: 
Jonathan Hoag (WVH 330, Office hours: Mon/Wed/Thu 13:30-14:30, email jhoag@ccs.neu.edu)






    
Course Web Site: http://www.ccs.neu.edu/home/riccardo/cs3500



    
Prerequisites: CS 2510



    
Textbooks: No textbook for the course. I will post
    lecture notes here. You may find the following books useful,
    although they are not required:

    
    
       
  • C. Hostermann, Object-Oriented Design and Patterns, 2nd
    edition, John Wiley and Sons, 2006
    • 
       
  • P. Sestoft, Java Precisely, 2nd edition, MIT Press, 2005.
    • 
   



    
Grading:  Grading will be based on weekly homeworks
    (50%), a midterm (25%), and a final exam (25%).
 


There may also be one or more quizzes, which may count as either
assignments or exams at the whim of the instructor.



While some program assignments may require students to work in
teams, most assignments and all quizzes and exams are individual.
Student work is subject to the Academic
Honesty and Integrity Policy. 



Security is an important aspect of
software development. In this course, students are expected to protect
the software they develop from plagiarism. The quality of
this protection will be graded. 


  

    
 



    
Schedule Outline and Lecture Notes


    
This schedule is subject to change without warning. Readings
    will be assigned to supplement lectures, and posted here.


    

    

    
Jan 12
  
    
Introduction

     
- Lecture notes 


    

    
Jan 15
  
    
ADTs: algebraic specifications

     
- Lecture notes 


    

    
Jan 19
  
    
ADTs: implementation in Java

     
- Lecture notes

            - Code
        


    

    
Jan 22
  
    
ADTs: equality

     
- Lecture notes 


    

    
Jan 26
  
    
Errors and exceptions

     
- Lecture notes

            - Java
            Tutorial on Exceptions 


    

    
Jan 29
  
    
Software testing

     
- Lecture notes

            - Programming
            with Assertions



    

    
Feb 2
  
    
Code reuse: Subclassing

     
- Lecture notes


    

    
Feb 5
  
    
Topics in subclassing

     
- Lecture notes

            - Java tutorial on packages


    

    
Feb 9
  
    
Subclassing from Multiple Classes

     
- Lecture notes


    

    
Feb 12
  
    
Design pattern: Functional iterators

     
- Lecture notes

            - Code


    

    
Feb 16
  
    
Polymorphism

     
- Lecture notes

            - Code

         - Java tutorial on  generics

         - A more technical tutorial by the person
         responsible for getting polymorphism into Java



    

    
Feb 19
  
    
Polymorphism (continued)

     
- Lecture
    notes

         - Code

    


    

    
Feb 23
  
    
Examples: Iterator Gadgets

     
- Lecture notes

            - Code

    


    

    
Feb 26
  
    
Midterm

     
 

    


    

    
Mar 9
  
    
Design Patterns: Map and Reduce

     
- Lecture notes

            - Code

    


    

    
Mar 12
  
    
Design Pattern: Laziness

     
- Lecture notes

            - Code

    


    

    
Mar 16
  
    
Code Reuse: Inheritance and Delegation

     
- Lecture notes

            - Java
            Tutorial on Inheritance. Note how they conflate
            inheritance and subclassing.

    


    

    
Mar 19
  
    
Multiple inheritance

     
- Lecture notes

          


    

    
Mar 23
  
    
Mutation

     
- Lecture notes 
 


    

    
Mar 26
  
    
Design pattern: adapters

     
- Lecture notes 
 


    

    
Mar 30
  
    
Subclassing and Mutation

     
- Lecture notes 
 


    

    
Apr 2
  
    
Design pattern: publish-subscribe

     
- Lecture
    notes

            - Code
 


    

    
Apr 9
  
    
Design pattern: model-view-controller

     
- Lecture notes

            - Code
 


    

    
Apr 13
  
    
Mixins in Scala

     
- The Scala
            programming language

            - Programming
            Scala, from O'Reilly
 


    

    
Apr 16
  
    
Iterators in Python

     
- The Python
            programming language

            - The Python
            tutorial

            - Code for lists from class

            - Sample session using
            the code from List.py 
 
 

    

    
Apr 20
  
    
Odds and Ends

     
 Final review 
 
 

  


     


    
 




    
Homeworks


    
Removed

    
 



    
Online Resources