Lab 7 - Fall 2019

More with rumors and pipes...

At the command line:

1. Bring up a terminal window by right-clicking on the desktop and selecting Open in Terminal in the pop-up menu
2. Create the directory where your lab7 is located by typing the following commands, pressing return after each command, at the Linux prompt:
   1. cd cs101
   2. mkdir lab7

Start on lab 7

• Your lab7 starter code contains the data definition, examples, and template function for the rumor-mill and for a pipeline. It also has the code we will developed yesterday and what we will look at this morning: water-running?.

1. Finish the function we began in class yesterday, add-gossip which takes a rumor mill and two person images: an old person who is already in the rumor mill and a new person. It produces the new augmented rumor mill. Add the new person to the rumor mill, receiving rumors from the old person. The old person must not already have two next persons.
2. Implement rumor-chain which takes a person image and a rumor mill and returns a list of person images representing everyone who must pass on a rumor for it to reach the given person. Return #false if the given person is never informed.
3. When the temperature drops well below freezing, it is recommended that homeowners turn on a faucet in the house, furthest away from where the water supply enters the house. The water should drip from the faucet, to help prevent the pipes from freezing. One dripping faucet is sufficient, but for this lab, we're going to get a little carried away… Add the new function, drip, which turns on all the faucets in the pipeline. Don't forget to follow the Design Recipe, which means writing tests (check-expect's) before you write the function body, and using the template for a pipeline as the starting point for the function body. You should have at least five (5) tests for this function.
4. Implement the modernize function as specified in the starter code, following the Design Recipe.

Log out

When you are done, close DrRacket by choosing Quit from the File menu, and then locate the logout option on the menu bar (lower right corner). Choose "Logout…" and follow any remaining prompts. Always remember to log out when you are done using the system, to ensure that no one else uses your account.