projects/10/Square/Main.jack


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// This file is part of www.nand2tetris.org
// and the book "The Elements of Computing Systems"
// by Nisan and Schocken, MIT Press.
// File name: projects/10/Square/Main.jack

// (derived from projects/09/Square/Main.jack, with testing additions)

/** Initializes a new Square Dance game and starts running it. */
class Main {
    static boolean test;    // Added for testing -- there is no static keyword
                            // in the Square files.
    function void main() {
      var SquareGame game;
      let game = SquareGame.new();
      do game.run();
      do game.dispose();
      return;
    }

    function void test() {  // Added to test Jack syntax that is not use in
        var int i, j;       // the Square files.
        var String s;
        var Array a;
        if (false) {
            let s = "string constant";
            let s = null;
            let a[1] = a[2];
        }
        else {              // There is no else keyword in the Square files.
            let i = i * (-j);
            let j = j / (-2);   // note: unary negate constant 2
            let i = i | j;
        }
        return;
    }
}