Chapter 9 - High-Level Language

Jack for the PerfectlyBalanced program.

Author: roboryman

09/PerfectlyBalanced/Array.vm

@@ -0,0 +1,23 @@
+function Array.new 0
+push argument 0
+push constant 0
+gt
+not
+if-goto IF_TRUE0
+goto IF_FALSE0
+label IF_TRUE0
+push constant 2
+call Sys.error 1
+pop temp 0
+label IF_FALSE0
+push argument 0
+call Memory.alloc 1
+return
+function Array.dispose 0
+push argument 0
+pop pointer 0
+push pointer 0
+call Memory.deAlloc 1
+pop temp 0
+push constant 0
+return

09/PerfectlyBalanced/Keyboard.vm

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+function Keyboard.init 0
+push constant 0
+return
+function Keyboard.keyPressed 0
+push constant 24576
+call Memory.peek 1
+return
+function Keyboard.readChar 2
+push constant 0
+call Output.printChar 1
+pop temp 0
+label WHILE_EXP0
+push local 1
+push constant 0
+eq
+push local 0
+push constant 0
+gt
+or
+not
+if-goto WHILE_END0
+call Keyboard.keyPressed 0
+pop local 0
+push local 0
+push constant 0
+gt
+if-goto IF_TRUE0
+goto IF_FALSE0
+label IF_TRUE0
+push local 0
+pop local 1
+label IF_FALSE0
+goto WHILE_EXP0
+label WHILE_END0
+call String.backSpace 0
+call Output.printChar 1
+pop temp 0
+push local 1
+call Output.printChar 1
+pop temp 0
+push local 1
+return
+function Keyboard.readLine 5
+push constant 80
+call String.new 1
+pop local 3
+push argument 0
+call Output.printString 1
+pop temp 0
+call String.newLine 0
+pop local 1
+call String.backSpace 0
+pop local 2
+label WHILE_EXP0
+push local 4
+not
+not
+if-goto WHILE_END0
+call Keyboard.readChar 0
+pop local 0
+push local 0
+push local 1
+eq
+pop local 4
+push local 4
+not
+if-goto IF_TRUE0
+goto IF_FALSE0
+label IF_TRUE0
+push local 0
+push local 2
+eq
+if-goto IF_TRUE1
+goto IF_FALSE1
+label IF_TRUE1
+push local 3
+call String.eraseLastChar 1
+pop temp 0
+goto IF_END1
+label IF_FALSE1
+push local 3
+push local 0
+call String.appendChar 2
+pop local 3
+label IF_END1
+label IF_FALSE0
+goto WHILE_EXP0
+label WHILE_END0
+push local 3
+return
+function Keyboard.readInt 2
+push argument 0
+call Keyboard.readLine 1
+pop local 0
+push local 0
+call String.intValue 1
+pop local 1
+push local 0
+call String.dispose 1
+pop temp 0
+push local 1
+return

09/PerfectlyBalanced/Main.jack

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+// Computes whether the same number of x's and y's appear in the input.
+class Main {
+  function void main() {
+    var PerfectlyBalanced balance;
+    var String input;
+    var char c;
+    var boolean exit;
+
+    do Main.header();
+    do Output.println();
+    while(true) {
+      let input = Keyboard.readLine("Enter the input: ");
+      if (input.length() > 0) {
+        if(input.charAt(0) = 81) {
+          do Output.printString("<<<QUITTING>>>");
+          do input.dispose();
+          do Sys.halt();
+        }
+      }
+      let balance = PerfectlyBalanced.new(input);
+      do Screen.clearScreen();
+      do Output.moveCursor(0, 0);
+      do Main.header();
+      do balance.output();
+      do balance.dispose();
+    }
+
+    return;
+  }
+
+  function void header() {
+    do Output.printString("<<<PROGRAM: PerfectlyBalanced>>>");
+    do Output.println();
+    do Output.printString("<<<DESC: Does input #ofx == #ofy?>>>");
+    do Output.println();
+    do Output.printString("<<<Press Q to quit execution>>>");
+    do Output.println();
+    do Output.println();
+
+    return;
+  }
+}