CMPS 144L Spring 2020
Lab #8: Positional Lists with Cursors

The files you are going to need are

• PLC.java: Positional List Cursor (interface)
• PLC_Exception.java: Positional List Cursor Exception
• PL_With_C.java: Positional List With Cursors (interface)
• PL_With_C_ViaArray.java: Positional List With Cursors Via Array (implements above interface)
• PL_With_C_Utils.java: Positional Lists with Cursors Utilties (for student to complete)
• PLC_Utils_Tester.java: Tester program

In the PL_With_C_Utils class are five stubbed methods that you are to attempt to complete. They are clearly marked by STUB! and their comments should suffice to explain their intended behavior. Several other (complete) methods are present, in part to give you examples that you can use as models. When you are finished, you should submit the source code file of this class to your lab8_dir folder. (Again: Submit the .java file, not the .class file!)

PLC_Utils_Tester is a Java application that you can use to test your work. You are free to modify it to suit your testing needs.

The remaining Java classes implement the "Positional List with Cursors" abstraction and are not to be modified. To view the full array of methods available to list and cursor objects, see the PL_With_C and PLC interfaces. (Unless you are interested in the gory details of implementation, don't view the contents of PL_With_C_ViaArray.)

Notes:

• You will probably notice that some methods involve the use of a generic type parameter (i.e., <T>), while others do not. Follow the rule that, if the method heading includes such a parameter, the declarations in the method body must be consistent with it. Thus, for example, in a method involving the generic type parameter <T>, a declaration of a local cursor variable cur would look like this:
  PLC<T> cur

  In a method whose heading does not mention a generic type parameter, the analogous declaration would be

  PLC cur
• As a method is about to finish execution, any local cursor variable whose value is neither null nor being returned to the caller should have its dispose() method invoked upon it. For example: cur.dispose() .