Examples

Math demos

examples/math_demos.lbd

fibonacci : Number -> Number = \n.
    (if (lt n 2) n (add (fibonacci (sub n 1)) (fibonacci (sub n 2))))

factorial : Number -> Number = \n.
    (if (eq n 0) 1 (mul n (factorial (sub n 1))))

-- Greatest common divisor, tail recursive.
gcd : Number -> Number -> Number = \a. \b.
    (if (eq b 0) a (gcd b (mod a b)))

isPrime : Number -> Bool = \n.
    let divides = \d. (eq (mod n d) 0) in
    let check = \d. (if (gt (mul d d) n) true (if (divides d) false (check (add d 1)))) in
    (and (gt n 1) (check 2))

(println "fibonacci 10 = " (fibonacci 10))
(println "factorial 10 = " (factorial 10))
(println "gcd 1071 462 = " (gcd 1071 462))
(println "primes below 30: " (filter isPrime (range 0 30)))

Output

fibonacci 10 = 55
factorial 10 = 3628800
gcd 1071 462 = 21
primes below 30: [2, 3, 5, 7, 11, 13, 17, 19, 23, 29]

Run it yourself from the repository root: lbd run examples/math_demos.lbd