add replace function to format that takes varying-length strings to replace.

add test for it
add error test for format.translate for different length translate args.

plugins/Format/plugin.py

@@ -90,6 +90,15 @@ class Format(callbacks.Plugin):
         irc.reply(text.translate(string.maketrans(bad, good)))
     translate = wrap(translate, ['something', 'something', 'text'])
 
+    def replace(self, irc, msg, args, bad, good, text):
+        """<substring to translate> <substring to replace it with> <text>
+
+        Replaces all non-overlapping occurrences of <substring to translate> 
+        with <substring to replace it with> in <text>.  
+        """
+        irc.reply(text.replace(bad, good))
+    replace = wrap(replace, ['something', 'something', 'text'])
+
     def upper(self, irc, msg, args, text):
         """<text>
 

plugins/Format/test.py

@@ -54,6 +54,10 @@ class FormatTestCase(PluginTestCase):
 
     def testTranslate(self):
         self.assertResponse('translate 123 456 1234567890', '4564567890')
+        self.assertError('translate 123 1234 123125151')
+    
+    def testReplace(self):
+        self.assertResponse('replace # %23 bla#foo', 'bla%23foo')
 
     def testUpper(self):
         self.assertResponse('upper foo', 'FOO')