As someone who has used JAX-RS (Java) and ASP.NET, APIs are basically created with these kinds of annotations right in the language.
@GET
public Character getCharacter(@PathParam("id") int id) {
return db.getCharacter(id);
}
op getCharacter(@path id: safeint): Character;
// TypeSpec
model Character {
name: string;
id: safeint;
status: "Alive" | "Dead";
class: Class;
}
enum Class { warrior; wizard; }
// C#
public class Character {
public string Name { get; set; }
public int Id { get; set; }
public Status Status { get; set; }
public CharacterClass CharacterClass { get; set; }
}
public enum Status { Alive, Dead }
public enum CharacterClass { Warrior, Wizard }