Funktionen und Kontrollfluss

let quadrat x = x * x
let addiere a b = a + b
let begruesse (name: string) = "Hallo, " + name + "!"
let plus10 = addiere 10
let verdopple = fun x -> x * 2

printfn "%d %d" (quadrat 7) (addiere 3 4)
printfn "%s" (begruesse "Mia")
printfn "%d" (plus10 5)
printfn "%d" (verdopple 21)

let zweimal f x = f (f x)
printfn "%d" (zweimal verdopple 5)

let komponiert = quadrat >> verdopple
printfn "%d" (komponiert 3)
printfn "%d" (3 |> quadrat |> verdopple)

let rec fak n = if n <= 1 then 1 else n * fak (n - 1)
let rec fib a b i = if i = 0 then a else fib b (a + b) (i - 1)
printfn "%d %d" (fak 10) (fib 0 1 40)

let teile a b = a / b, a % b            // Tupel als Rückgabe
let q, r = teile 17 5
printfn "%d %d" q r

let inline addiereAlles (x: ^a) (y: ^a) = x + y
printfn "%d %.1f" (addiereAlles 1 2) (addiereAlles 1.5 2.5)

let vorzeichen n =
    if n > 0 then "positiv"
    elif n < 0 then "negativ"
    else "null"

let fizzbuzz n =
    match n % 3, n % 5 with
    | 0, 0 -> "FizzBuzz"
    | 0, _ -> "Fizz"
    | _, 0 -> "Buzz"
    | _ -> string n

let note n =
    match n with
    | 1 -> "sehr gut"
    | 2 | 3 -> "gut bis befriedigend"
    | n when n >= 4 && n <= 5 -> "ausreichend bis mangelhaft"
    | _ -> "ungültig"

printfn "%s %s %s" (vorzeichen 5) (vorzeichen -2) (vorzeichen 0)
printfn "%s" (String.concat " " (List.map fizzbuzz [1 .. 15]))
printfn "%s %s %s" (note 1) (note 3) (note 9)
let status = if 15 > 10 then "groß" else "klein"
printfn "%s" status

for i in 1 .. 5 do printf "%d " i
printfn ""
for i in 5 .. -1 .. 1 do printf "%d " i
printfn ""
for x in [ "a"; "b"; "c" ] do printf "%s " x
printfn ""
for i in 0 .. 2 .. 10 do printf "%d " i
printfn ""

let mutable k = 0
while k < 3 do
    printf "w%d " k
    k <- k + 1
printfn ""

[ 1; 2; 3 ] |> List.iter (fun x -> printf "%d " (x * x))
printfn ""
[ "x"; "y" ] |> List.iteri (fun i s -> printf "%d:%s " i s)
printfn ""