CSC297.Java, Class 14: Lists

Admin:
* Bishop's latest assignment: Histogram, due Wed.
* Sam's latest assignment: Test the various versions of cdr.
* Sam's other assignment: Think about how to make addToFront more efficient.
* Centering

Overview:
* Review: A List Interface
* Question: How would *you* implement this interface
* Technique one: Arrays
* Technique two: Cons cells (Pairs)

Notes on Centering

    // An idea: Put width/2 spaces on the left and width-1-width/2 spaces
    // on right.
    // A problem: If the object requires more than one space, you're screwed.
    // Revised idea:
    //   (1) Determine the length of "the string".
    //   (2) Subtract that length from width.
    //   (3) Follow the earlier strategy
    // A concern: What if the string is longer than the width?
    //   (a) Throw an exception.
    //   (b) Truncate the string. [Dictatorial selection]
    //   (c) Just print the string as is.  [Popular Vote]
                                                                                
Important Morals:

* It works because *any* object can be converted to a sting.  (A wonder of polymorphism.)
* When you need to print a long string of similar characters, a substring command may be more efficient than a for loop.  (It looks more clever, at the very least.)
* You should be able to solve problems like this.