QED

A Java interpreter for QED programming language

QED?

QED is an abbreviation of the Latin words "Quod Erat Demonstrandum" which loosely translated means "that which was to be demonstrated". It is usually placed at the end of a mathematical proof to indicate that the proof is complete.

Features

Closures

fun make_counter(n) {
  var count = n - 1;
  fun counter() {
    counter = counter + 1;
    return counter;
  }
  return counter;
}

var counter = make_counter(0);
print counter(); // 0
print counter(); // 1

Arrays

var arr = [1, 2, nil, "Hello"];
print arr[2]; // nil
print arr[4]; // index out of range error
arr[0] = 0;
print arr; // [0, 2, nil, "Hello"];

Classes and Inheritance

class Vehicle {
  fun init(wheels) {
    this.wheels = wheels;
  }
  
  fun start() {
    ...
  }
}

class Car > Vehicle {
  fun init() {
    super.init(4);
  }
  
  fun start() {
    super.start();
    ...
  }
}

var car = Car();
print car.wheels; // 4