Blorp by Example

Option

Option makes absence explicit with Some(value) or None.

Some

Some(value) carries a present value.

some.brp

value: Option[Int] = Some(42)

None means no value is present.

none.brp

missing: Option[String] = None

Blorp uses Option instead of null references.

option.brp

name: Option[String] = input("name> ")

match forces both Some and None paths to be considered.

match-option.brp

match maybe_name:
    Some(name): print(name)
    None: print("no name")

get_or(default) turns an Option[T] into a T.

get-or.brp

name: String = maybe_name.get_or("guest")

map transforms the value only when it is Some.

map.brp

doubled: List[Int] = values.map(pure func(x): x * 2)

and_then chains a function that also returns Option.

and-then.brp

first_name: Option[String] = user.and_then(pure func(u): u.name)

name-input.brp

func main(args: List[String]) -> Int:
	match input("name> "):
		Some(name):
			print("Hello, " + name.trim())
			0
		None:
			print("Goodbye")
			0

terminal

blorp run name-input.brp