Lab2

Lab #2: Introducing the Debugger

Objectives: The objective of this assignment is introduce you to the Smalltalk debugger.
Upon completion, you should be able to:

• Correct errors detected by Smalltalk at run-time.
• Insert breakpoints in your code to trace it.
• Trace changes in the values of objects.

• Debugger
• Inspector
• File list

If all went well in the first lab, you can start Squeak by double-clicking on your personal image.
For purposes of speed and safeguarding against server crashes, it is recommend to work from the temp directory of the local hard drive. C:temp is the only directory that is writable by students.
If Windows prompts you for a program to open the filename.image with you can specify S:appsssqueaksqueak.exe

Improving Code FileOut

Procedure:

Open the debugger tutorial web page for this lab.

Try to run the code along with the tutorial:
|bank|
bank := AccountList new initialize.
bank open: 1234 name: 'P. Coad'.
(bank account:1234) deposit:1000.

You copy and paste the text into a Workspace and executing the "do it" command.
Using the tutorial you should be able to find and fix the first error in the lab.

Now instead of running the above code, try running the test code by typing:
AccountList example1
in the workspace and "do it".

Look at the code example1 (hint: It's a class method!) and try to figure out what it is supposed to do. Examination and manipulation of the values in the example should give you some hints about the problems with the Account operations. The simple workspace code at the end of the web tutorial might also be useful.

Use the debugger to track down the logical and syntactical errors in the Account class. Fix them.
There are no errors in the AccountList class.

Notes
The comment for the Account class specifies that:

• Service charges should be applied whether or not balance is negative.
• Service charges should not be counted as withdrawals.
• Withdrawals are allowed only if sufficient funds are available.
• Withdrawals are counted until monthly processing, then start over.
• Minimum balance is set to current balance at the end of the month.
• Minimum balance is used to calculate the interest for the month

You are free to create additional code to test the Accounts. If you want us to see this code (i.e., you want to get some credit and are pretty lost), make it a class method of Account called example, and include comments liberally.

There are a total of 5 errors in the lab besides the one described in the tutorial.  They are a of mix of logical errors and syntax errors

Finishing the lab:

After you have completed debugging your code, fileout all the code using the same steps as in Lab1.
You should turn in a fileOut of the code you wrote.

Mail the file to your TA any way that is convenient. Here is one way to do so:

   1.Select Run from the Start menu and type in:

          telnet lennon.cc

   2.Login to lennon using your CoC login and password.
   3.Change to your 2390 directory, eg cd ~/cs2390 (or wherever you put your code)
   4.Type:

          /usr/ucb/mail -s "TI,Lab2,My SocialSecurity Number or Student Number" cs2390@prism.gatech.edu < DebugLab.st

     (Replace My SocialSecurity Number or Student Number with your student number, e.g.,
     345544545).

Remember, this is just one way of turning in your code.  You can use whatever e-mail program you are comfortable with as long as you insert the code as the body of the message AND you follow the format for the subject explained above:
"TI,Lab2,My SocialSecurity Number or Student Number"

PLEASE NO ATTACHMENTS!