Riot Language specification

Data types

Variables

     // normal variable
var num1 = 1

// multiple variables
var num1, num2

// multiple variables with value
var num2 = 2, num3 = 3

// multiple variables with diferent type
var num4: int = 4, say: str = "string"
  

Constants

     // normal constant
const num1 = 1

// multiple constants (initial value is required)
const num1: int = 1, num2: int = 2

// multiple constants with diferent type
const num3: int = 3, say: str = "string"
  

Tuple

     // normal tuple
var tuple = (1, "Hello", true)

// tuple with type
var tuple: tuple<int, str> = (1, "Hello")

// tuple with other type declaration (recomended)
var otherTuple: (int, str) = (1, "Hello")
  

Objects

     // normal object
var obj = {
  name: "John",
  age: 20
}

// object with type
var obj: object = {
  name: "John",
  age: 20
}

// object with other type declaration (recomended)
interface Person {
  name: str,
  age: int
}

var otherObj: Person = {
  name: "John",
  age: 20
}

// object with mixed types
var obj: object = {
  name: "John",
  age: 20,
  sayHello: fn(): void -> print("Hello")
}

// object with mixed types (recomended)
interface Person {
  name: str,
  age: int,
  sayHello: () -> void 
}

var otherObj: Person = {
  name: "John",
  age: 20,
  sayHello: fn(): void -> print("Hello")
}
  

Lists

     // normal list
var list = [1, 2, 3]

// list with type
var listOfStrings: list<str> = ["Hello", "World"]

// list with other type declaration (recomended)
var otherListOfStrings: srt[] = ["Hello", "World"]

// list with mixed types
var mixedList: list<any> = ["Hello", 1, true]

// list with mixed types (recomended)
var otherMixedList: any[] = ["Hello", 1, true]

// list with multiple types
var multipleTypesList: list<int, str, bool> = [1, "Hello", true]

// list with multiple types (recomended)
var otherMultipleTypesList: (int, str, bool)[] = [1, "Hello", true]
  

Functions

     // normal function
fn sayHello() {
  print("Hello")
}

// function with parameters
fn sayHello(name: str) {
  print("Hello " + name)
}

// function with return
fn sayHello(name: str): str {
  return "Hello " + name
}

// function with parameters and return
fn sayHello(name: str, age: int): str {
  return "Hello " + name + ", you are " + age + " years old"
}
  

Arrow Functions

     // normal arrow function (single line)
var sayHello = (): void -> print("Hello")

// normal arrow function (multiple lines)
var sayHello = (): void -> {
  print("Hello")
  print("World")
}

// anonymous function
const pet = {
  getName: fn(): str {
    return "Dog"
  }
}

// anonymous arrow function
const person = {
  getAge: (): int -> 20
}

// async/await is supported by default!!!

// anonymous async function
const pet = {
  getName: fn(): str {
    await sleep(1000)
    return "Dog"
  }
}

// anonymous async arrow function
const person = {
  getAge: (): int -> {
    await sleep(1000)
    return 20
  }
}

// method style
const person = {
  getAge (): int {
    return 20
  }
}
  

Classes

Basic class

     class Person {
  // constructor
  constructor(name: str, age: int) {
    this.name = name
    this.age = age
  }

  // method
  sayHello () {
    print("Hello " + this.name + ", you are " + this.age + " years old")
  }
}

// create object
var person = new Person("John", 20)

// with named parameters

var person = new Person(name: "John", age: 20)
  

Static class

     class StaticClass {
  // static method
  static sayHello () {
    print("Hello")
  }
}
  

No constructable class

     class NoConstructableClass {
  // private constructor
  public NoConstructableClass () {
    return 'Hello World'
  }
}

// create string of no constructable class
const message: str = NoConstructableClass()

print(message) // Hello world
  

Inheritance

     class Person {
  // constructor
  constructor(name: str, age: int) {
    this.name = name
    this.age = age
  }
  // method
  sayHello () {
    print("Hello " + this.name + ", you are " + this.age + " years old")
  }
}

// extend class Person
class Student extends Person {
  // constructor
  constructor(name: str, age: int, school: str) {
    super(name, age)
    this.school = school
  }

  // method
  sayHello () {
    print("Hello " + this.name + ", you are " + this.age + " years old and you study in " + this.school)
  }
}

// extends multiple classes

class StudentWithFriends extends Person, Student {
  // constructor
  constructor(name: str, age: int, school: str) {
    super.Person(name, age)
    super.Student(name, age, school)
  }

  // method
  sayHello () {
    print("Hello " + this.name + ", you are " + this.age + " years old and you study in " + this.school)
  }
}
  

Interfaces

     interface Person {
  name: str
  age: int
  readonly constructor (name: str, age: int)
}

// implements interface
class Student implements Person {
  name: str
  age: int
  constructor(name: str, age: int) {
    this.name = name
    this.age = age
  }

// method
  sayHello () {
    print("Hello " + this.name + ", you are " + this.age + " years old")
  }
}
  

Generics

     // generic function
fn sayHello<T>(name: T): T {
  return "Hello " + name
}
  

     // use generic function

const name: str = sayHello<str>("John")

// generic arrow function

var sayHello = <T>(name: T): T -> "Hello " + name

// use generic arrow function
var name: str = sayHello<str>("John")
  

in progress…