CS 1101 - Aterm 10

Homework 3 - Unions of Data

Due: Friday, September 10, at 5pm

Read the expectations on homework. You should do this assignment with your homework partner.

Assignment Goals

The Assignment

A major-league baseball team keeps data on its players. Players are either position players or pitchers. Information kept for both types of players includes the player's name, age, and the player's yearly salary (in millions of dollars). In addition, the following information is kept for position players: a symbol representing the player's field position (C, 1B, 2B, 3B, SS, LF, CF, RF); the number of at-bats; the number of runs scored; the number of hits; the batting average; and the number of errors. For pitchers, the following information is kept: the number of innings pitched, the earned run average, the number of wins, and the number of losses. (For those of you not familiar with baseball, here is some information about baseball statistics).

Writing Programs for Mixed Data

  1. Develop a data definition for players that covers both types of players (position and pitcher) described above (you should have at least three data definitions; remember that the data definition for a union consists only of a comment). Give several examples of players.

  2. Provide the templates for your data definitions in Problem 1 (you should provide as many templates as you have data definitions).

  3. Write a function position which consumes a player and returns a symbol. If the player is a position player, the function returns the player's field position. If the player is a pitcher, the function returns the symbol 'P.

  4. Write a function near-retirement? that consumes a player and produces a boolean. The function returns true if the player's age is greater than 35.

  5. Write a function add-bonus that consumes a player and produces a player. If the player is a position player with a batting average greater than .320, or if the player is a pitcher with an earned run average less than 2.5, then the player's salary is increased by 10%. Otherwise, the player is returned unchanged.

What to Turn In

Here is the gradesheet for Homework 3.

Using web-based turnin, turn in a single file containing all code and documentation for this assignment. Files should be named according to the file-naming conventions for homework files. Make sure both partners' names and login names appear in a comment at the top of the file.