--- a/configuration/configuration.py	Tue Apr 17 11:36:01 2012 -0700
+++ b/configuration/configuration.py	Tue Apr 17 12:50:10 2012 -0700
@@ -110,13 +110,18 @@
     """option that keeps track if it is seen"""
     # TODO: this should be configurable or something
     def take_action(self, action, dest, opt, value, values, parser):
-        """add the parsed option to the set of things parsed"""
         optparse.Option.take_action(self, action, dest, opt, value, values, parser)
+
+        # add the parsed option to the set of things parsed
         if not hasattr(parser, 'parsed'):
             parser.parsed = set()
         parser.parsed.add(dest)
-        # TODO (see following comment)
-        # if self.type in ...
+
+        # switch on types
+        formatter = getattr(parser, 'cli_formatter')
+        if formatter:
+            formatter = formatter(dest)
+            setattr(values, dest, formatter(getattr(values, dest)))
 
 ### plugins for option types
 ### TODO: this could use a bit of thought
@@ -147,6 +152,9 @@
         kw['action'] = 'store'
         return args, kw
 
+    def take_action(self, value):
+        return value
+
 class BoolCLI(BaseCLI):
 
     def __call__(self, name, value):
@@ -195,13 +203,25 @@
         kw['type'] = 'float'
         return args, kw
 
+class DictCLI(ListCLI):
+
+    delimeter = '='
+
+    def take_action(self, value):
+        bad = [i for i in value if self.delimeter not in i]
+        if bad:
+            raise AssertionError("Each value must be delimited by '%s': %s" % (self.delimeter, bad))
+        return dict([i.split(self.delimeter, 1) for i in value])
+
 # TODO: 'dict'-type cli interface
 
 types = {bool:  BoolCLI(),
          int:   IntCLI(),
          float: FloatCLI(),
          list:  ListCLI(),
+         dict:  DictCLI(),
          None:  BaseCLI()} # default
+
 __all__ += [i.__class__.__name__ for i in types.values()]
 
 class Configuration(optparse.OptionParser):
@@ -320,6 +340,10 @@
     ### methods for optparse
     ### XXX could go in a subclass
 
+    def cli_formatter(self, option):
+        handler = self.types[self.options[option].get('type')]
+        return getattr(handler, 'take_action', lambda x: 1)
+
     def optparse_options(self, parser):
         """add optparse options to a OptionParser instance"""
         for key, value in self.items():

--- a/tests/example.py	Tue Apr 17 11:36:01 2012 -0700
+++ b/tests/example.py	Tue Apr 17 12:50:10 2012 -0700
@@ -17,6 +17,8 @@
                     'type': bool},
         'test_timeout': {'help': "Time to wait for the browser to output to the log file",
                          'default': 1200},
+        'preferences': {'type': dict,
+                        'flags': ['-p', '--pref']}
         }
 
 if __name__ == '__main__':