exercises.fs

// Exercise 1
let isLeap (year:int) :bool =
    year % 4 = 0 && year % 100 <> 0 || year % 400 = 0

// Exercise 3
let rec map mapFn list =
    match list with
    | [] -> []
    | x::xs -> [mapFn x] @ map mapFn xs


// Exercise 4
type Expression =
    | Constant of int
    | Sum of Expression * Expression
    | Product of Expression * Expression
    | Divide of Expression * Expression
    | Minus of Expression * Expression

let rec evaluate (expr: Expression) :int =
    match expr with
    | Constant(x) -> x
    | Sum(x,y) -> (evaluate x + evaluate y)
    | Product(x,y) -> (evaluate x * evaluate y)
    | Minus(x, y) -> (evaluate x - evaluate y)
    | Divide(x, y) -> (evaluate x / evaluate y)


// Exercise 5
type Input =
    {
        Name: string
        Code: int
        State: bool
    }

type InputController =
    {
        Keyboard: Input list
        Mouse: Input list
    }

let getKeysPressed(input: InputController): Input list =
    let pressedKeys (event: Input list) =
       event
       |> List.filter (fun (x: Input) -> x.State)

    pressedKeys input.Keyboard @ pressedKeys input.Mouse

[<EntryPoint>]
let main argv =
    // Exercise 1
    printfn "%A" (isLeap 1700)
    printfn "%A" (isLeap 1800)
    printfn "%A" (isLeap 1900)
    printfn "%A" (isLeap 1600)
    printfn "%A" (isLeap 2000)

    // Exercise 3
    printfn "%A" (map (fun x -> x * 2) [1;2;3])

    // Exercise 4
    printfn "%A" (evaluate (Divide(Sum(Constant(3),Constant(1)),Constant(2))))

    // Exercise 5
    let smallController = { Keyboard = [{ Name = "Up"; Code = 0; State = false };{ Name = "Down"; Code = 1; State = true };{ Name = "Left"; Code = 2; State = false };{ Name = "Up"; Code = 0; State = true }]; Mouse = [{ Name = "LeftClick"; Code = 10; State = false };{ Name = "RightClick"; Code = 10; State = true }]}
    printfn "%A" (getKeysPressed smallController)

    0