misc-files

Miscellaneous files of my coding endeavours. Separated by exercise sets.

List of exercise sets:

Greek Flag:

• greek-flag-final.arr: A small Pyret program that draws the old greek flag.
• greek-flag-function-final.arr: A variation of the above program, now operating as a function. Can be executed by writing greek-flag(desired unit size) e.g. greek-flag(100).
• greek-flag-final.rkt: The Racket version of greek-flag-final.arr.

Miscellaneous:

• car-drawing.rkt: Drawing of a simple car in Racket, from the Part I, exercise 5 of the book "How to Design Programs".
• tree-drawing.rkt: Drawing of a simple tree in Racket, from the Part I, exercise 5 of the book "How to Design Programs".
• small-banner.rkt: A small banner with text in Racket, using the text-font property.
• happybirthday.py: A small Python 3 program that asks for the name of a person and prints a happy birthday wish. Based on section 1.11.2 of Loyola University's Python 3 hands-on tutorial.

Traffic lights:

• traffic-lights.rkt: A Racket program that prints the next color on a traffic light, depending of which is the current one. Partially based on an example in the section 1.6 of Part I of the book "How to Design Programs", which didn't flesh out the example enough, so that the changes would be realistic and correct. Can be executed simply by invoking the next-color variable (optionally, after modifying the current-color variable).
• traffic-lights.scm: The Scheme version of the above program. Can be executed simply by invoking the next-color variable (optionally, after modifying the current-color variable).
• traffic-lights.arr: The Pyret version of the above program. Can be executed by writing next-color("name of current color") e.g. next-color("red").
• traffic-lights-function.rkt: traffic-lights.rkt as a function. Can be executed by writing (next-color name of current color) e.g. (next-color "green").
• traffic-lights-function.scm: The Scheme version of the above program. Execute as above.
• traffic-lights-function-cond.scm: The above program with cond instead of nested if statements, for more readability. Execute as above.
• traffic-lights-function-cond.rkt: The Racket version of the above program. Execute as above.

Mall:

• mall.rkt: A small Racket program, inspired by exercise 7 of the Part I of the book "How to Design Programs". It implements an if statement for the following hypothetical scenario: "Suppose you want to decide whether today is an appropriate day to go to the mall. You go to the mall if it is either not sunny or if today is Friday (because that is when stores post new sales items)."(ibid). Can be executed simply by invoking the decision variable (optionally, after modifying the sunny and friday variables).
• mall.arr: The Pyret version of the above small program. Can be executed by writing decision(boolean value of sunny, boolean value of friday) e.g. decision(false, true).
• mall.scm: The Scheme version of the above small program. Can be executed simply by invoking the decision variable (optionally, after modifying the sunny and friday variables).
• mall.clj: The Clojure version of the above program.
• mall.lisp: The Common Lisp version of the above program. Executed as above, difference being that "t" is true and "nil" is false.
• mall-function.rkt: mall.rkt as a function. Execute by writing (decision state of sunny boolean state of friday boolean) e.g. (decision #false #true).
• mall-function.scm: The Scheme version of the above. Execute by writing (decision state of sunny boolean state of friday boolean) e.g. (decision #f #t).

Shapes:

• shapes.rkt: A small Racket program, based on the exercise 8 of the Part I of the book "How to Design Programs". Decides on whether a rectangle or square shape is tall, wide, or square depending on its width and height. Includes sample examples for all 3 cases. Can be executed simply by invoking the dimensions variable.
• shapes.arr: The Pyret version of the above program. Can be executed by writing dimensions(desired shape) e.g. dimensions(rectangle(90,20,"outline","black")).

Hours to wages:

• hours-to-wages.arr: A small Pyret program that, given a number of hours worked, computes the corresponding salary, taking in account the premium offered for overtime. Based on the exercises of section 3.5 of the book "Programming and Programming languages". The variables are the rate per hour, the number of hours, and the overtime threshold. Can be executed by writing hours-to-wages-at-rate(rate, hours, overtime threshold) e.g. hours-to-wages-at-rate(10,45,40). Care has been taken to disallow setting the value of hours, rate and/or overtime threshold to zero and below.
• hours-to-wages.rkt: The Racket version of the above program. Executed by invoking the compute variable, optionally after modifying the hours, rate, and overtime-threshold variables.
• hours-to-wages.scm: The Scheme version of the above program. Execute as above.
• hours-to-wages.lisp: The Common Lisp version of the above program. Execute as above.
• hours-to-wages-mark2.rkt: An extensive rewrite of hours-to-wages.rkt, consolidating the if statements that verified whether the numbers were above zero, and adding a way to flag any non-numeric input. Executed by invoking the compute variable, optionally after modifying the hours, rate, and overtime-threshold variables.
• hours-to-wages-mark2.scm: The Scheme version of the above program. Execute as above.
• hours-to-wages-mark2-function.rkt: Similar to hours-to-wages-mark2.rkt, but now as a function, which also changes its way of execution. Can be executed by writing (compute rate hours overtime-threshold), substituting as necessary e.g. (compute 10 45 40).
• hours-to-wages-mark2-function.scm: The Scheme version of the above program. Execute as above.
• hours-to-wages-input.rkt: Similar to hours-to-wages.rkt, but the program now offers input fields for the numbers. Execution: after the numbers have been inputted, type compute in the REPL.
• hours-to-wages-function-input.rkt: As above, only as a function. Execute by writing (compute) -with the parentheses- in the REPL.

Switching computer:

• switching-computer.arr: A small Pyret program that says to switch on the computer if there are new messages in the inbox. Based on any real-life case where one might want to do that. Can be executed by writing switching-computer(boolean value of new-messages) e.g. switching-computer(true).
• switching-computer.rkt: The Racket version of the above program. Can be executed simply by typing switching-computer, optionally after setting the new-messages boolean variable as desired.
• switching-computer.scm: The Scheme version of the above program. Can be executed the same way as above.
• switching-computer.lisp: The Common Lisp version of the above program. Can be executed as above, with the difference that "t" is true and "nil" is false.
• switching-computer-function.rkt: switching-computer.rkt as a function. Can be executed by writing (switching-computer new-messages boolean) e.g. (switching-computer #true).
• switching-computer-function.scm: The Scheme version of the above. Can be executed by writing (switching-computer new-messages boolean) e.g. (switching-computer #t).

Value:

• value.rkt: A small Racket program, based on the exercise 9 of the Part I of the book "How to Design Programs". Its premise is as follows: "Exercise 9. Add the following line to the definitions area of DrRacket: (define in "hello"). Then create an expression that converts whatever in represents to a number. For a string, it determines how long the string is; for an image, it uses the area; for a number, it decrements the number, unless it is already 0 or negative; for #true it uses 10 and for #false 20."(ibid). Only difference is the renaming of the in variable to something somewhat more expressive. Also given in the comments is a sample shape.
• value-function.rkt: The function version of the above file. Execute by writing (numberify value) e.g. (numberify "hello").