Waddle

Waddle is a strongly-typed object-oriented toy programming language whose syntax is partially inspired by Kotlin and Ruby.

• Object-oriented language.
• Statically typed language with type inference.
• The last value evaluated in a method is its return value.
• Everything is an object.

Documentation

Have a look in the examples directory to learn more.

Installation

$ npm install -g waddle

Usage

Run Repl:

waddle

or run file:

waddle examples/hello.waddle

Examples of code

Basic:

// comment

"This is a string" // res0: String = "This is a string"
"Hello, " + "Max" // res1: String = "Hello, Max"

1 + 2 // => res2: Int = 3
-2 * 3 + (1 - 2) // res3: Int = -7

2e4 // res4: Double = 20000
3.14 // res5: Double = 3.14

10.toString() // res6: String = "10"
15.+(1).*(3) // res7: Int = 48

if (true) "true" else "false" // res8: String = "true"
if ("hello" == "he" + "llo") {
  42
} else {
  -1 
} // res9: Int = 42

"hello".length() // res10: Int = 5
"how are you?".at(2) // res11: String = "w"
"abscde".replace("a", "111") // res12: String = "111bscde"

null // res13: Null = null
null.toString()

100.unary_-() // res14: Int = -100

1.instanceOf("Int") //res15: Bool = true
1.instanceOf("String") //res16: Bool = false

Booleans :

true // res0: Bool = true
false // res1: Bool = false
!false // res2: Bool = true
1 >= 3 // res4: Bool = false
2 == "hey" // res5: Bool = false
true || false // res6: Bool = true
true && true // res7: Bool = true
false.unary_!() // res8: Bool = true

Let:

let message: String = "Hello, World!" in {
  IO.println(message)
}
// type inference
let message = "Hello, World!" in {
  IO.println(message)
}

let a = 2, b = 3 in {
  a + b
} // res0: Int = 5

let a = 2, b = 3 in a + b // res1: Int = 5

While:

let i = 1 in {
  while (i <= 10) {
    IO.println(i)
    i += 1
  }
} // 1 2 3 4 5 6 7 8 9 10

Variables:

var message: String = "Hello" // message: String = Hello!
// type inference
var message1 = "Hello, World!" // message1: String = Hello!

Functions:

def add(a: Int, b: Int): Int = {
  a + b
}
// add(a: Int, b: Int): Int
add(42, 1) // res0: Int = 43

def add2(a: Int, b: Int): Int = a + b
// add2(a: Int, b: Int): Int
add2(42, 1) // res0: Int = 43

def sayHi() = IO.println("Hi!")
sayHi() // Hi!

IO:

IO.println(1 + 2) // 3
IO.println(-2 * 3 + (1 - 2)) // -7

Math:

Math // Math: Math$ = Math$@0
Math.pi() // res0: Double = 3.141592653589793
Math.log2(16) // res1: Double = 4
Math.max(16, 42) // res10: Int = 42

OOP:

class Person(firstname: String, lastname: String) {
  var age: Int = 0
  
  def firstname(): String = {
    firstname
  }
  
  def setFirstname(name: String) = {
    firstname = name
  }
  
  def whoIsPrivate() = {
    IO.println(somePrivateMethod())
  }
  
  // override func
  override def toString(): String = {
    "Person(" + firstname + ", " + lastname + ")"
   }
  
  // functions are public by default
  // private func
  private def somePrivateMethod(): String = "I'm private!"
}

// inheritence
class Employee(
  firstname: String,
  lastname: String,
  company: String
) extends Person(firstname, lastname) {
  def company(): String = company
  def setCompany(c: String) = company = c
}

var person = new Person("John", "Doe") // person: Person = Person(John, Doe)

person.whoIsPrivate() // I'm private!
IO.println(person) // Person(John, Doe)

person.firstname() // res8: String = "John"
person.setFirstname("Max")
person.firstname() // res9: String = "Max"

var employee = new Employee("John", "Doe", "company")
employee.firstname() // res10: String = "John"
employee.company() // res11: String = "company"

Fraction class in Waddle:

class Fraction(n: Int, d: Int) {
  var g: Int = gcd(Math.abs(n), Math.abs(d))

  var num: Int = n / g
  var den: Int = d / g

  def num(): Int = num
  def setNum(n: Int) = num = n / gcd(Math.abs(n), Math.abs(den))

  def den(): Int = den
  def setDen(d: Int) = den = d / gcd(Math.abs(num), Math.abs(d))

  def +(that: Fraction): Fraction = new Fraction(
        num * that.den() + den * that.num(),
        den * that.den()
      )

  def +(that: Int): Fraction = this + new Fraction(that, 1)

  def -(that: Fraction): Fraction = new Fraction(
        num * that.den() - den * that.num(),
        den * that.den()
      )

  def -(that: Int): Fraction = this - new Fraction(that, 1)
  def *(that: Fraction): Fraction = new Fraction(num * that.num(), den * that.den())
  def *(that: Int): Fraction = this * new Fraction(that, 1)
  def /(that: Fraction): Fraction = this * new Fraction(that.den(), that.num())
  def /(that: Int): Fraction = this / new Fraction(that, 1)

  override def ==(that: Object): Bool = {
      if (!that.instanceOf("Fraction"))
          false
      else {
          let frac = that as Fraction in {
              num == frac.num() && den == frac.den()
          }
      }
  }

  override def toString(): String = num + if (den > 1) "/" + den else ""

  private def gcd(a: Int, b: Int): Int = if (b == 0) a else gcd(b, a % b)
}

Super:

class A {
  def a(): String = super.toString()
}

IO.println(new A().a()) // A@0

This:

class B {
  def b(): B = this
}

var b = new B()
IO.println(b.b()) // B@2
IO.println(b.b().b().b().b().b()) // B@3

Lists: examples/list.waddle

Module system:

// dir/my_module.waddle
// Use `export` keyword to export class
export class A {
  def a(): Int = 42
}

export class B {
  def b(): Int = 13
}

// main.waddle
import A, B from "./dir/my_module"
// or
// import A, B from "./dir/my_module.waddle"
// or
// import A, B from "./dir" // to import all files recursively

IO.println(new A().a()) // 42
IO.println(new B().b()) // 13

Builtin modules:

import LinkedList from "collections/list"
// or just ...`from "collections"`

IO.println(new LinkedList()) // []

Building

Pre-reqs

To build and run this app locally you will need a few things:

• Install Node.js;

Getting start

• Clone the repository

git clone --depth=1 https://github.com/maxbarsukov/waddle.git

• Install dependencies

cd waddle
npm install

• Run

npm run start

• Tests

npm test

• Linting

npm run lint

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/maxbarsukov/waddle. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

The package is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Waddle project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.