Added swap to rpn.

ChangeLog

@@ -1,3 +1,5 @@
+	* Added a swap function to Math.rpn.
+	
 	* Changed the logging infrastructure significantly; each plugin
 	now has its own logger (and thus logfile), in addition to being
 	logged in the main logfile.

plugins/Math.py

@@ -151,6 +151,7 @@ class Math(callbacks.Privmsg):
 
     _rpnEnv = {
         'dup': lambda s: s.extend([s.pop()]*2),
+        'swap': lambda s: s.extend([s.pop(), s.pop()])
         }
     def rpn(self, irc, msg, args):
         """<rpn math expression>

test/test_Math.py

@@ -60,6 +60,9 @@ class MathTestCase(PluginTestCase, PluginDocumentation):
         self.assertResponse('rpn 2 3 4 + -', str(2-7))
         self.assertNotError('rpn 2 degrees')
 
+    def testRpnSwap(self):
+        self.assertResponse('rpn 1 2 swap', 'Stack: [2, 1]')
+
     def testRpmNoSyntaxError(self):
         self.assertNotRegexp('rpn 2 3 foobar', 'SyntaxError')