CSC153 2004S, Class 37: Designing Objects

Admin:
* Sam is hoarse (If you didn't understand that, I won't talk and I'll just write)
* Survey results
  * Class is going too fast: 1 1 2 2.5 2 4
  * less talk/more lab: 2 2.5 4 2 5 4 5
  * less lab/more talk: 4 2.5 2 3 1 1 1
* Questions on the homework?
  * Do we have to use the six Ps?  No, but it would be nice.
  * Can we pass functions?  With a clever hack (to be discussed)
* Read EIJ, Chapter O2 (Inheritance)
* Cool convo tomorrow

Overview:
* Field trip to science elbow! (Free coffee and stuff!)
* Passing functions
* Object-oriented design basics, revisited
* Protection
* Reuse
* Exercise

Fun with functions as parameters:
* You can simulate higher-order functions with objects
* Some functions are easier to build more quickly
* Can still generalize

About object-oriented design:
* Program in terms of objects
* Three related concepts:
  Encapsulation - Protect and separate interface from implementation
  Inheritance - 
    Extend: Add fields methods
    Modify: Override methods
      Example: The function thing above
      Question: Why are anonymous functions useful?  Because they save programmer effort.
  Polymorphism
  Polymorphism vs. overloading
  * Polymorphism: Write function once, can apply it to similar objects
  * Overloading: Write function with the same name multiple times with different parameter types

Common problem in object-oriented design: How
do I choose which objects to make and how do
I decide fields and methods of those objects?
* Idea from reading: Tell stories