Added and passed comparison test

creature.go

@@ -144,7 +144,7 @@ func (machine *Machine) Execute(offset int) (err error) {
 			// checks if the last word on the stack is less than the
 			// second to last word on the stack
 			less := 0
-			if machine.Pop() > machine.Pop() {
+			if machine.Pop() < machine.Pop() {
 				less = 1
 			}
 			machine.Push(less)

creature_test.go

@@ -45,8 +45,13 @@ func TestArithmetic(test *testing.T) {
 		PUSH, 3,
 		PUSH, 12,
 		DIV,
+		
+		PUSH, 6,
+		PUSH, 8,
+		MOD,
 	}, test)
 
+	modResult := machine.Pop()
 	divResult := machine.Pop()
 	mulResult := machine.Pop()
 	subResult := machine.Pop()
@@ -56,6 +61,7 @@ func TestArithmetic(test *testing.T) {
 	test.Log("sub:", subResult)
 	test.Log("mul:", mulResult)
 	test.Log("div:", divResult)
+	test.Log("mod:", modResult)
 
 	if addResult != 5 {
 		test.Log("add result should be", 5)
@@ -76,4 +82,60 @@ func TestArithmetic(test *testing.T) {
 		test.Log("div result should be", 4)
 		test.Fail()
 	}
+
+	if modResult != 2 {
+		test.Log("mod result should be", 2)
+		test.Fail()
+	}
+}
+
+func TestComparison(test *testing.T) {
+	machine := runMachineTest([]int {
+		PUSH, 6,
+		PUSH, 6,
+		EQ,
+		
+		PUSH, 4,
+		PUSH, 324,
+		GT,
+		
+		PUSH, 324,
+		PUSH, 4,
+		LT,
+		
+		PUSH, 6,
+		PUSH, 54,
+		NEQ,
+		
+	}, test)
+
+	neqResult := machine.Pop()
+	ltResult := machine.Pop()
+	gtResult := machine.Pop()
+	eqResult := machine.Pop()
+
+	test.Log("eq:", eqResult)
+	test.Log("gt:", gtResult)
+	test.Log("lt:", ltResult)
+	test.Log("neq:", neqResult)
+
+	if eqResult != 1 {
+		test.Log("eq result should be", 1)
+		test.Fail()
+	}
+
+	if gtResult != 1 {
+		test.Log("gt result should be", 1)
+		test.Fail()
+	}
+
+	if ltResult != 1 {
+		test.Log("lt result should be", 1)
+		test.Fail()
+	}
+
+	if neqResult != 1 {
+		test.Log("neq result should be", 1)
+		test.Fail()
+	}
 }