Casamento de padrões com is

type Shape {
	Circle    { radius: Int }
	Rectangle { width: Int, height: Int }
}

proc main(): void {
	shape := Shape.Circle(4)
	if shape is Shape.Circle(r)            { echo "círculo, r={r}" }
	else if shape is Shape.Rectangle(w, _) { echo "retângulo, w={w}" }
}

proc main(): void {
	command := ["move", "north", "2"]
	if command is ["move", dir, ...steps] { echo "{dir}, {len(steps)} a mais" }
	else if command is ["stop"]           { echo "parar" }
}

proc main(): void {
	path := "/users/42/posts/7"
	if path is "/users/{id}/posts/{postId}" { echo "{id} / {postId}" }
}