Problems 63 - 82

11/7 - 11/8 Posn

• a posn (short for position) can keep track of two values, usually x and y.  It is a structure that is built into the Racket language.

Intro to Posn 1

Intro to Posn 2

Intro to Posn 3 - writing functions that use posns

• 63  - show the stepper changes as comments

• 64  - the formula is really simple and not the same as 63

11/11 - 11/12   Structures

Intro to structs 1 code examples

Intro to Structs 1 - video

Intro to structs 2 code examples

Intro to Structs 2 video

• 65 - on Intro to structs 1

• 66 - make an example of each struct

• 67 - they give you an example of a balld.  Make a few more.

• 68 - make a ballf using the same values that are used in the ball1 example

• 69 - you can do this using various boxes (under insert). However, it is easier to write it on paper

11/13 - 11/14

• 70 - I will ask you what changes that you would make to find other values in the make-centry

• 71 - you should be able to explain to me the steps (you can learn this from the stepper)

Due 57 - 68

11/15 & 11/18
• 72 - you will have to scroll up to just after exercise 70 to find the first phone structure

11/19 - 11/20
• 73 - it will take a posn and a number, for example (make-posn 2 5) and 7, and return (make-posn 7 5)

• 74 - add tests and see how this interactive mouse program works.  You now know how to have programs use the keyboard and mouse

• 75 - using the stepper may help you to understand how these functions interact

Due 69 - 72

11/21 - 11/22
• 76 - a shorthand method for writing data definitons is shown on the Intro to Structs 1 & 2 code examples

• 77 - write a structure definition and data definition

• 78 - here are a few examples to help you figure out this problem

(three-letter-word  "c" "a" "t")

(three-letter-word  "e" #false "f")

12/2 - 12/3
• 79 - give an example for each bullet point.  For example: Lakewood and Columbine are examples of Jeffco high schools, while Cherry Creek and Fairview are not.

• 80 - examples of templates are shown in Intro to Structs 1 & 2

Due 73 - 80

12/4 - 12/5
• 81 & 82 - you may wish to skip these problems and continue to problems 83 - 87, the Editor Problem