CSC151.01 2014F, Class 03: An Introduction to Scheme

Overview

Preliminaries

Grab a playing card and sit at the computer associated with the card. (There's a map to help you.) (We'll assign you to a new partner and a new place every few days using this process.)
Thursday at 10 am, I will hold a review session. It's an opportunity for you to ask anything you'd like about the class.
My office hours are now posted on the course Web. MThF 1:45-3:15, plus walking hours from 1:15-1:45. Sorry for the delay. There is also a signup sheet outside my office.
After the preliminaries we'll jump right into lab.

Note: Please send a short (one paragraph) reflection on any extra credit activity you attend. And reflect, don't summarize.

Awesome show at the Faculoner gallery.
CS Extras Thursday at 4:30 p.m. in Science 3821. Adam Arsenault on his internship at the Free Software Foundation.

Take two minutes to chat with your partner to see if you have questions.
I'll write down all of the questions and then try to answer them.
After that, we'll do lab.
Do we need the hash tag open bracket?
- Usually, the computer will type things for you.
  Lab

Surprise! square is not defined.
- Computer science professors are clearly sentient and malicious.
- (Just in case I haven't told you, computers are sentient and malicious.)
- You don't need square and we'll learn how to define it next Monday. But some of you are impatient. In case you want to define square, you can use (define square (lambda (x) (* x x)))
- (define square sqr) also worksk
You never know when instructions will be ambiguous.
- Save as ratings.rkt.
- "Add a rating named s-and-b-rating"
How did you know that the square root of big-long-number was 371?
- Multiplied it by itself in Racket.
- Used the sqr function in Racket.