Fixed issue with pushing to stack

creature.go

@@ -207,7 +207,7 @@ func (machine *Machine) instruction() (instruction int) {
 // should be called then the stack pointer is really small compared to the
 // actual stack size, or the stack pointer is bigger than the stack.
 func (machine *Machine) reallocateStack() {
-	reallocatedStack := make([]int, machine.pointer*3/2)
+	reallocatedStack := make([]int, machine.pointer*2)
 	copy(reallocatedStack, machine.stack)
 	machine.stack = reallocatedStack
 }
@@ -219,6 +219,7 @@ func (machine *Machine) Push(word int) {
 	if len(machine.stack) <= machine.pointer {
 		machine.reallocateStack()
 	}
+	machine.stack[machine.pointer] = word
 }
 
 // Pop pops the last word off of the stack, and returns it, decreasing the stack

creature_test.go

@@ -2,6 +2,28 @@ package creature
 
 import "testing"
 
+func TestPush(test *testing.T) {
+	machine := Machine {
+		Program: []int {
+			0x0, 654,
+		},
+	}
+
+	err := machine.Execute(0)
+	if err != nil {
+		test.Log("machine exited with error:", err)
+		test.Fail()
+	}
+
+	result := machine.Pop()
+	test.Log("popped:", result)
+
+	if result != 654 {
+		test.Log("result should be", 654)
+		test.Fail()
+	}
+}
+
 func TestArithmetic(test *testing.T) {
 	machine := Machine {
 		Program: []int {