Traits

Traits name behavior that generic code can require.

Standard Traits

Standard traits include Stringable, Equatable, Orderable, and numeric operator traits.

func main(args: List[String]) -> Void:
	text: String = 42.to_string()

Bounds

A bound such as T: Orderable lets a generic function use ordering operations.

pure func larger[T:Orderable](a: T, b: T) -> T:
	if a > b:
		a
	else:
		b

Operator Traits

Operators are available when the type implements the required trait.

pure func add_pair[T:Addable](a: T, b: T) -> T:
	a + b

Implementing Traits

An implements block provides trait functions for a type.

implements Stringable for User:
	pure func to_string(user: User) -> String:
		user.name

Example

users.brp

record User {name: String, score: Int}


implements Stringable for User:
	pure func to_string(user: User) -> String:
		user.name + ": " + user.score.to_string()


pure func larger[T:Orderable](a: T, b: T) -> T:
	if a > b:
		a
	else:
		b


func main(args: List[String]) -> Void:
	users: List[User] = [{name = "Ada", score = 91}]
	match users.get(0):
		Some(user): print(user) -- prints: Ada: 91
		None: print("no users")

Try it

terminal

blorp run users.brp