CS 227 Lecture -*- Outline -*-

* Introduction to Part 3: Managing State.

	We now start to discuss the imperative programming style.
	So far what we have done is called functional (or applicative) style.
		expressions only, nothing changing
		if we want to model something changing,
			we have to pass it around
			Remember the change-making problem?
	In imperative programming, every procedure has an implicit argument
		which is the state of the entire program
		can change that state by using vector-set! (Ch 9)
			and set!, set-car!, set-cdr! (Ch 11).

	Imperative programming is by far the most widely
	   used style of programming. (If you have programmed
	   before, you have seen some of it.) It is an
	   essential part of each programmer's tool kit.

	Neat thing about this is how it mixes with the functional programming
		ideas we saw in chapter 7.  The combination has great power.
		We call this "mostly functional programming" after H. Baker.

	If we have time, will see how to use that power to do object-oriented
		programming (Ch. 12).

** Vectors

	Chapter 9 introduces vectors. These allow constant
	time access to the elements. They can also be
	updated in constant time. (Like arrays in other languages.)

** Mutation

	Chapter 11 applies the idea of changing state, mutation,
	to variables and lists. (Changing the state of a variable
	is called assignment.)

** Object-oriented progrmming

	Chapter 12, which we may not get to, describes a 
	combination of higher-order process (as in Chapter 7)
	and state change: OOP.