At the end of today's class you should

KNOW:
what is meant by mixed data (unions of data).

BE ABLE TO:
write a data definition for mixed data with a Java interface
communicate to Java that a compound data structure belongs to a mixed data collection
write functions over mixed data
choose a set of good test cases for a function over mixed data.

Exercises:

0. Develop the function perimeter, which consumes either a circle or a square and computes the perimeter.

1. Develop structure and data definitions for a collection of zoo animals. The collection includes

* spiders, whose relevant attributes are the number of remaining legs (we assume that spiders can lose legs in accidents) and the space they need in case of transport;
* elephants, whose only attributes are the space they need in case of transport;
* monkeys, whose attributes are intelligence and space needed for transportation.

Develop the function fitsHuh. The function consumes a zoo animal and the volume of a cage. It determines whether the cage is large enough for the animal. 

2. The administrators of metropolitan transportation agencies manage fleets of vehicles. Develop structure and data definitions for a collection of such vehicles. The collection should include at least buses, limos, cars, and subways. Add at least two attributes per class of vehicle.

3. Add rectangles to our 'area' program from class. For our purposes, the description of a rectangle includes its upper-left corner, its width, and its height.

4. Extend the data definition of #1 so that animals endorse products, which are described by a product name and a product company. Write a function called 'endorse' that consums an animal and a product and produces an animal that endorses that product.

5. Develop the function 'biggest', which consumes two animals from #1 and returns the one that takes up more space. (Hint: This requires a new function in the interface that ISN'T 'biggest'.)

Optional Exercises:

0. Develop the function 'center', which consumes either a circle or a square and computes the center point

1. Add ellipses to our 'area' program from class. (Use Google/Wikipedia to discover what defines an ellipses.)

2. Develop the function 'accident', which consumes an animal from #1 and returns a new animal that has been in an accident. Spiders lose legs in accidents, monkeys lose intelligence, and elephants shrink slightly.