nand2tetris/projects/12/archive/Main.jack

class Main{
    static Array mem;
    

    /** Initializes the screen, and locates the cursor at the screen's top-left. */
    function void test_init() {
        let mem = 0;
        return;
    }

    function void main(){
        var String s;
        var int i;
        let s = String.new(10);
        do Main.test_init();
        let s = Main.readLine("String: ");
        let i = Main.readInt("INT: ");
        do Output.printString(s);
        do Output.printInt(i);
        return;
    }

    
    function char keyPressed(){
        return mem[24576];
    }
    
    function int readInt_stolen(String message){
        var starting a;
        var int b;
        let a = Main.readLine_stolen(message);
        let b = String.intValue(a);
        do String.dispose(a);
        return b;
    }
    function string readLine_stolen(String message){
        var char a, b ,c;
        var String d;
        var bool e;
        let d = String.new(80);
        do Output.printString(message);
        let b = String.newLine();
        let c = String.backSpace();
        while (~e){
            let a = Main.readChar();
            let e = a = b;
            if (~e){
                if (a = c){
                    do d.eraseLastChar();
                }
                else{
                    do d.appendChar(a);
                }
            }    
        }
        return d;
    }
    /**								
     * Displays the message on the screen, reads from the keyboard the entered
     * text until a newline character is detected, echoes the text to the screen,
     * and returns its value. Also handles user backspaces.
     */    
    function String readLine(String message){
        var String s, b;
        var char c;
        let s = String.new(100);
        do Output.printString(message);
        while (true){
            let c = Main.readChar();
            if (c = 128){
                return s;
            }
            else{
                if (c = 129){
                    do s.eraseLastChar();
                }
                else{
                    do s.appendChar(c);
                }
            }
        }
    }
    /**								
     * Waits until a key is pressed on the keyboard and released,
     * then echoes the key to the screen, and returns the character 
     * of the pressed key.
     */
    function char readChar(){
        var char a, b;
        do Output.printChar(0);
        while ((b = 0) | (a > 0)){
            let a = Main.keyPressed();
            if (a > 0){
                let b = a;
            }
        }
        do Output.printChar(String.backSpace());
        do Output.printChar(b);
        return b;
    }
    

    
    /**								
     * Displays the message on the screen, reads from the keyboard the entered
     * text until a newline character is detected, echoes the text to the screen,
     * and returns its integer value (until the first non-digit character in the
     * entered text is detected). Also handles user backspaces. 
     */
    function int readInt(String message) {
        var String s;
        var char c;
        let s = String.new(100);
        do Output.printString(message);
        while (true){
            let c = Main.readChar(c);
            if (c = 128){
                return s.intValue();
            }
            else{
                if (c = 129){
                    let s = s.eraseLastChar();
                }
                else{
                    if ((c > 47) & (c < 57)){
                        let s = s.appendChar(c);
                    }
                }
            }
        }
    }
}