Exercise: Creating Contracts From Examples

Directions: For each of the following collections of Examples, write the contract for the function above the examples.

; big-triangle : number string -> image (EXAMPLE (big-triangle 100 "red") (triangle 100 "solid" "red")) (EXAMPLE (big-triangle 100 "orange") (triangle 100 "solid" "orange"))
; purple-square : number -> image (EXAMPLE (purple-square 15) (rectangle 15 15 "outline" "purple")) (EXAMPLE (purple-square 6) (rectangle 6 6 "outline" "purple"))
; banner : string -> image (EXAMPLE (banner "Game Today!") (text "Game Today!" 50 "red")) (EXAMPLE (banner "Go Team!") (text "Go Team!" 50 "red")) (EXAMPLE (banner "Exit") (text "Exit" 50 "red"))
; twinkle : number string -> image (EXAMPLE (twinkle 5 "outline") (star 5 "outline" "yellow")) (EXAMPLE (twinkle 15 "solid") (star 15 "solid" "yellow")) (EXAMPLE (twinkle 36 "outline") (star 36 "outline" "yellow")
; half : number -> number (EXAMPLE (half 2) (/ 2 2)) (EXAMPLE (half 4) (/ 4 2)) (EXAMPLE (half 9) (/ 9 2))
; how-long? : string -> number (EXAMPLE (how-long? "Soccer") 6) (EXAMPLE (how-long? "Cupcakes") 8) (EXAMPLE (how-long? "Hi Mom") 6) (EXAMPLE (how-long? "Cheese pizza") 12)

Bootstrap:Algebra by Emmanuel Schanzer, Emma Youndtsmith, Kathi Fisler, and Shriram Krishnamurthi is licensed under a Creative Commons 4.0 Unported License. Based on a work at www.BootstrapWorld.org. Permissions beyond the scope of this license may be available by contacting schanzer@BootstrapWorld.org.