Finishing touches

app/src/main/java/Programs/Factorial.java

@@ -0,0 +1,20 @@
+package Programs;
+
+import hatelace.*;
+import hatelace.instructions.*;
+
+public class Factorial extends Program {
+    public Factorial() {
+        Address n = new Address(0),
+                fac = new Address(1);
+
+        add(new Copy(new IntWord(5), n));
+        add(new Copy(new IntWord(1), fac));
+        add(new JumpEq(6, n, new IntWord(1)));
+        add(new Mul(fac, n, fac));
+        add(new Add(n, new IntWord(-1), n));
+        add(new Jump(2));
+        add(new Print(fac));
+        add(new Halt());
+    }
+}

app/src/main/java/hatelace/Computer.java

@@ -15,7 +15,7 @@ public class Computer {
     public void run() {
         // Note that the instructions themselves are responsible for incrementing the PC
         for(ProgramCounter PC = new ProgramCounter(); PC.getPC() < this.program.size() && !PC.halted() && PC.getSysTicks() < 100; ) {
-            program.getInstructions()[PC.getPC()].execute(this.memory, PC);
+            program.get(PC.getPC()).execute(this.memory, PC);
         }
     }
 }

app/src/main/java/hatelace/Main.java

@@ -1,6 +1,6 @@
 package hatelace;
 
-import hatelace.instructions.*;
+import Programs.Factorial;
 
 public class Main {
     public static void main(String[] args) {
@@ -8,26 +8,15 @@ public class Main {
 
         Memory memory = new IntMemory(64); // 64 words of memory
         Computer computer = new Computer(memory);
+        Program program = new Factorial();
 
-        Address n = new Address(0), fac = new Address(1);
-
-        Program program = new Program(new Instruction[] {
-            new Copy(new IntWord(5), n),
-            new Copy(new IntWord(1), fac),
-            new JumpEq(6, n, new IntWord(1)),
-            new Mul(fac, n, fac),
-            new Add(n, new IntWord(-1), n),
-            new Jump(2),
-            new Print(fac),
-            new Halt()
-        });
         computer.load(program);
         computer.run();
         memory.dump();
 
         // Print the program
         System.out.println("Program:");
-        for (Instruction instruction : program.getInstructions()) {
+        for (Instruction instruction : program) {
             System.out.println(instruction);
         }
 

app/src/main/java/hatelace/Program.java

@@ -1,17 +1,6 @@
 package hatelace;
 
-public class Program {
+import java.util.ArrayList;
-    private Instruction[] instructions;
 
-    public Program(Instruction[] instructions) {
+// This is simply an intermediate class to comply with the specified API requirements.
-        this.instructions = instructions;
+public abstract class Program extends ArrayList<Instruction> {}
-    }
-
-    public Instruction[] getInstructions() {
-        return this.instructions;
-    }
-
-    public int size() {
-        return this.instructions.length;
-    }
-}