Add a SWP swap operation (xchg two values on top of stack)

gte/turmit.py

@@ -365,6 +365,15 @@ class Turmit(object):
             @param a int : value
         '''
         pass
+
+    @RpnOp
+    def swp(self, a, b):
+        ''' @brief Swap the two values on top of the stack
+            @param a int : v1
+            @param b int : v2
+        '''
+        self._push(b)
+        self._push(a)
     
     @RpnOp
     def jmp(self, offset):

tests/test_turmit.py

@@ -285,3 +285,16 @@ class TurmitOperationTestCase(unittest.TestCase):
         self.assertEqual(t.shead, 10)
         t.pop()
         self.assertEqual(t._cur, len(t._stack) - 1)
+
+    def test_swp(self):
+        ''' Test turmit swp() method '''
+        self._rpn('swp', 2)
+
+        t = Turmit()
+        t._push(42)
+        t._push(1337)
+        t.swp()
+        self.assertEqual(t._cur, 1)
+        self.assertEqual(t.shead, 42)
+        t._pop()
+        self.assertEqual(t.shead, 1337)