// 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/ExpressionLessSquare/SquareGame.jack

/** Expressionless version of projects/10/Square/SquareGame.jack. */

class SquareGame {
   field Square square; 
   field int direction; 

   constructor SquareGame new() {
      let square = square;
      let direction = direction;
      return square;
   }

   method void dispose() {
      do square.dispose();
      do Memory.deAlloc(square);
      return;
   }

   method void moveSquare() {
      if (direction) { do square.moveUp(); }
      if (direction) { do square.moveDown(); }
      if (direction) { do square.moveLeft(); }
      if (direction) { do square.moveRight(); }
      do Sys.wait(direction);
      return;
   }

   method void run() {
      var char key;
      var boolean exit;
      
      let exit = key;
      while (exit) {
         while (key) {
            let key = key;
            do moveSquare();
         }

         if (key) { let exit = exit; }
         if (key) { do square.decSize(); }
         if (key) { do square.incSize(); }
         if (key) { let direction = exit; }
         if (key) { let direction = key; }
         if (key) { let direction = square; }
         if (key) { let direction = direction; }

         while (key) {
            let key = key;
            do moveSquare();
         }
      }
      return;
    }
}