CSC153 2004S, Class 44: Implementing Lists with Nodes (Linked Lists)

Admin:
* Today's prospective:
  * Jesse, WV, Dartmouth et al., Open Source
* Saul's personal hero speaks tonight at 8:30
  * Saul says "I know I'm going to be there tonight."
  * Saul says "He is a beacon of hope in these dark times."
  * Saul says "He is a voice of hope for all that is right and good in the world in this wilderness of fascistic liberal wishiwashiness."
  * Yes, "fascistic" is a word with a subtly different meaning from "fascist"
* Thanks for Friday
* Questions on the exam?
  * Purpose of interfaces?
    * Polymorphism: You can build methods that use the interface as a parameter type; You can call these methods with any class that implements them
      * Helpful example one: GeneralizedList
    * Sometimes it doesn't make sense to implement anything when you're talking in generalities
  * Given that mayPrecede is already associated with Orderable, why do we need a separate mayPrecede for Orders, given that it will be applied to Orderable objects?
    * Reponse: What are the normal parameters to an order's mayPrecede?
    * Orders can order orderable objects in a different way than the default.
    * Orders can order objects that have no default orders
  * How do you print a double to only a certain number of decimal points?
    * It's obvious: Read the documentation for java.text.DecimalFormat.  
    * Convert to a string, find the decimal point, and then take a substring
    * Multiply by 100, truncate, and do some more crap
    * Implement your own doubles
  * Which methods should I evaluate for their exceptional characteristic?  (That is, when you say "Which of the methods above might throw an exception?", which methods do you mean?)
    * Orderable.mayPrecede, Order.mayPrecede, Addable.add
  * Most Orders are not Orderable
  * If we are calling a method (like an array index) that throws an Exception, do we have to throw a separate exception?
    * No
  * You can't write, can you?
    * No.
  * How do I implement a sorting algorithm?
    * public void sort(Order order, DynamicArray stuff)
    * E.g., sort(new OrderStudentsByAnnoyingnessDecreasing(), myCSC153)
      myCSC153.dropFirst(); // Bye ....
      myCSC153.dropFirst(); // Bye ....
     
* What was the thesis of "Lists with current considered harmful"?

Overview:
* Detour: Implementing <code>isValid</code>
* Linked lists: Implementing lists with nodes.
* Implementing basic methods
* Implementing ordered methods
* Cool tricks