Thursday, April 5 - Guest lecturer, Pat Palmer
"Programming Without Coding"

The approaching maturity of web services technology and growth of free tools, de facto standards and services on the World Wide Web has enabled a new type of "software development" to spring up, in which a minimum of actual code needs to be written, and the bulk of the complexity is handled by (often remote) third-party software. We will explore examples of feeding data to web services to create graphs, charts, mash-ups, musical scores or even sound files. This new type of "software development" is good for students of science and technology fields, who can explore their subject area in new ways with such services.

CIS 550 is being offered in the fall. It was inadvertently omitted from the earlier posted schedule of courses. I strongly recommend this course for everyone.

Other good courses for MCIT students: CIS 552 Advanced Programming, CIS 554 Programming Paradigms (disclaimer: I teach this course), CIS 573 Software Engineering (Chris), others according to individual interest.

For those who are interested, I've just posted a new version of the Tokenizer test, OfficialTokenizerTest2.java. This version fixes the errors noted on Piazza--and, of course, I did some minor code cleanup.

My TAs, Sarah and Chris, have been doing a great job of keeping up with the grading. Were it not for the errors in my tests, you would have your grades by now. The remaining delay is my fault.

Also, please note that if, because of an error in my tests, you changed your Tokenizer's next() method to return an ERROR Token when it should throw a NoSuchElementException, you should probably change it back. (Eclipse's Local History command can do that for you.)

• When I asked that you turn in a program that takes no more than a minute to run, I was talking about your program; we are not going to run JRat on your program.
• The following original (or "close to" original) step sort program works fine. The problem was that at some point the ">=" turned into ">".

  def stepsort(array):
      step = len(array) // 2
      # Note: Integer division is / in Python 2, // in Python 3
      while step > 0:
          i = 0
          while i < len(array) - step:
              if array[i] > array[i + step]:
                  array[i], array[i + step] = array[i + step], array[i] # swap
                  if i >= step:
                      i -= step + 1
              i += 1
          step = step // 2

  You may use any correct version in your assignment (test it!).

The enum TokenType declares eight values (INT, ..., ERROR). Since these are public, unless you write a Javadoc comment for each and every one of them, you'll get a warning message.

You really should specify how each of these is defined, but I do that in the Javadoc for my Tokenizer class, where I think it's more useful. If you do that, it's okay to ignore the warning in the TokenType class.

Also, I've added to the specification that toString in the Token class should return a string of the form type:text.

I've been checking my own code, and will be asking for slightly fewer warning messages. In Code style, you may continue to Ignore:

• Unqualified access to instance field
  • Says you should put this. in front of every use of an instance variable. That's probably a good idea--it makes it obvious what your "global" variables are--but it's not a convention I've ever followed.
• Non-externalized strings
  • The idea of "externalization" is to put all your strings into a file, so that if you ever need to translate your program into another language (like Chinese, not Python), all you have to do is translate the contents of this file, not edit the program.

Sam Moelius is giving a talk on "Java Generics", Thursday, February 9, at 1:30 inWu & Chen. You should attend if you can, because:

• You might learn something useful about Java generics, and
• He is applying for a lecturer position--possibly for MCIT.

Errors in current assignment (you knew there had to be some!):

In the definitions of leftmostDescendant() and rightmostDescendant(), I said that they each returned a leaf. That isn't necessarily so! They return the furthest node that can be reached by going only left or going only right. The leftmost descendant may have a right child, and the rightmost descendant may have a left child. Sorry for the confused definition.

Assignment 1 FAQ (Frequently Asked Questions):

Can I use toString() to display results?

No. The description of void add(T value) says, "Displays the new contents of the data structure, with the top or first element as the first line in the display." That isn't what toString() does.

What should the Iterate buttons do?

They should create a new Iterator for the given collection (Stack, Queue, or Deque). If you already have an Iterator for that collection, it should be discarded.

For Deque, how to I keep track of whether I'm iterating forward or backward?

Save the direction in some variable in your program.

How should I use the Data text field?

This field is used for both input and output. Some buttons, like Size, should display a number in the Data text field. To add a value to a collection, type it into the Data field and press Push (or Enqueue, or Add To Front/Rear). The user should not edit the JTextArea displays; in fact, feel free to setEditable(false) to these three text areas.

I'm not blacking out my site today, but I will mention techdirt, which is a site I read regularly.

As Will Rogers said, "We have the best Congress money can buy."

The language for this course is Java 7; A Look at Java 7's New Features. You can get Java 7 from:

• Windows, Solaris, and Linux: http://www.oracle.com/technetwork/java/javase/downloads/index.html
• Macintosh: http://code.google.com/p/openjdk-osx-build/wiki/OpenJDK7MACOSXPORT

Other software we will be using: Eclipse (I'm using Eclipse Java EE IDE for Web Developers, but Eclipse Classic 3.7 should do), JRat (documentation is here), CountTokens.jar, and SwingExamples.jar.