Blorp by Example

Functions

Functions make data flow explicit with parameter and return types.

Parameters

Parameters are named and typed inside parentheses.

params.brp

pure func add(a: Int, b: Int) -> Int:
    a + b

Return Types

The return type follows ->. The last expression supplies the returned value.

returns.brp

pure func label(score: Int) -> String:
    "score: " + score.to_string()

Local Helpers

Use a small helper when the public function wants a simpler interface than the implementation.

helpers.brp

pure func outer(n: Int) -> Int:
    pure func inner(x: Int) -> Int:
        x + 1
    inner(n)

Recursion

Recursive functions call themselves directly.

recursive.brp

pure func count_down(n: Int) -> Int:
    if n == 0:
        0
    else:
        count_down(n - 1)

@tailrec

@tailrec asks the compiler to verify the recursive call is in tail position.

tailrec.brp

@tailrec
pure func loop(n: Int, acc: Int) -> Int:
    if n <= 0:
        acc
    else:
        loop(n - 1, acc + n)

Example

factorial.brp

pure func factorial(n: Int) -> Int:
	if n <= 1:
		1
	else:
		n * factorial(n - 1)


@tailrec
pure func factorial_loop(n: Int, acc: Int) -> Int:
	if n <= 1:
		acc
	else:
		factorial_loop(n - 1, n * acc)


func main(args: List[String]) -> Void:
	print(factorial(5).to_string())
	print(factorial_loop(5, 1).to_string())

Try It

terminal

blorp run factorial.brp