Programming Language: BSL

Purpose: To practice designing lists and start our first project

Expectations

You should submit a single $.$rkt file containing your responses to all exercises via the Handins Server. We accept NO email submissions. Failure to submit a $.$rkt file will result in a $0.$ Please note that a $.$rkt~ file or $.$bak file will NOT be acceptable and will result in a $0.$

You are only allowed to use the language specified at the top of this page. This includes any additional libraries, except $2$htdp$/$image and $2$htdp$/$universe$.$ Failure to do so will result in a $0.$

Your code MUST conform to the guidelines outlined in the style guide on the course website. The style guide may be updated as the semester progresses so please remember to read it before submitting each assignment.

Make sure to hit "Save Definitions" in DrRacket before submitting your file!

Unless otherwise stated, for all function design problems you must provide $($i$)$ a signature, $($ii$)$ a purpose statement, $($iii$)$ check$-$expects, and $($iv$)$ the actual code, in the language specified at the top of this page. Write at least $3$ check$-$expects for every function you design. Additionally, ensure that you get full code coverage, meaning, DrRacket is not showing any "halloween colors" $($orange on black$)$ for any parts of your code $($except templates$).$

Unless otherwise stated, for all data design problems you must provide $($i$)$ a definition, $($ii$)$ an interpretation, $($iii$)$ examples, and $($iv$)$ a template.

Some exercises may require you to design additional data for full credit, even if this isn't made explicit in the question.

Make sure to avoid any of the banned functions.

Functions to Avoid

For this class, unless we tell you otherwise, you must not use the following functions:

equal?

equal~$?$

eq$?$

eqv?

assq

assoc

assv

member

member?

memq

remove

remove$-$all

Project: FunPaint

In Homework $4,$ you were asked to implement a simple circle painter. Over $2$ or $3$ homeworks, we will extend this idea to a shape painting program called FunPaint.

Task $1$ Design union data to represent shapes. Your data type should support at least a circle, a rectangle, a triangle and a star. You can assume that all shapes have a solid color. Each shape should also contain enough information to be drawn using the corresponding function from the image library.

Note, when naming your structures, avoid using circle, triangle, rectangle, or star to avoid clashing with the image library functions.

Task $2$ Design data for a placed shape, which associates a shape with a position $($x$,$ y$)$ on a canvas.

Task $3$ Design data to represent a list of placed shapes. This will represent the shapes drawn so far in our program's world state.

Task $4$ Design the world state for FunPaint. Plan for the user to have the ability to change the next shape to be placed, its color and its size. Provide at least $4$ examples of a world state with multiple different shapes placed.

Task $5$ Design the first prototype version of FunPaint, which only provides a static view of the current world state. Implement this as a world program, fun$-$paint. Yes, you only need to provide the to$-$draw handler.

A small sample of the currently selected shape in the currently selected color should be displayed in the top left corner of the canvas. The current size should be rendered as a number next to or under the shape sample.