hw01
scheme warm-up

Due in class Feb.Groundhog.
Turn in on WebCT. In addition, if you're local, bring a hardcopy to class.

The exercises below are from the (free, online) book How to Design Programs.

2.2.1
2.4.1 [Just report the error message, and explain in a few words.]
3.3.2, 3.3.3, 3.3.4
If you make the right helper-method for 3.3.3, then 3.3.4 will be pretty easy to implement.

To experiment with functions-which-create-and-handle-images in drscheme, select Language > Add Teachpack…, and select the teachpack “world.ss”. Then you should be be able to evaluate the following:

(rectangle 80 20 'solid 'blue)
(circle 20 'solid 'red)
(ellipse 80 20 'outline 'orange)

(overlay (rectangle 80 20 'outline 'blue)
         (circle 20 'solid 'red))
; Think of 'overlay' as being "addition for images"

; overlay with an offset:
(overlay/xy (rectangle 80 20 'outline 'blue)
            30
            10
            (circle 20 'solid 'red))


; If you want to explore documentation:
;   In drscheme, position the caret on a function-name
;   like 'overlay/xy', and hit F1.

Write a method which takes in a size, and returns an image of a donut. (Mmmm, doughnut.)
Write a method eye which takes a size, and returns an image of an eye.

Examples:

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©2009, Ian Barland, Radford University
Last modified 2009.Apr.20 (Mon) Please mail any suggestions
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hw01 scheme warm-up

hw01
scheme warm-up