--- a/fetch.py	Wed Nov 09 16:33:29 2011 -0800
+++ b/fetch.py	Wed Nov 09 16:54:51 2011 -0800
@@ -24,11 +24,20 @@
     def match(cls, _type):
         return _type == cls.type
 
-    def __init__(self, url):
+    def __init__(self, url, clobber=False):
+        self.subpath = None
+        if '#' in url:
+            url, self.subpath = url.rsplit('#')
         self.url = url
 
     def __call__(self, dest):
-        raise NotImplementedError
+        raise NotImplementedError("Should be called by implementing class")
+
+    @classmethod
+    def doc(cls):
+        """return docstring for the instance"""
+        retval = getattr(cls, '__doc__', '').strip()
+        return ' '.join(retval.split())
 
 ### standard dispatchers - always available
 
@@ -61,6 +70,8 @@
 
     def __call__(self, dest):
         assert os.path.isdir(dest)
+        if self.subpath:
+            raise NotImplementedError("should extract only a subpath of a tarball but I haven't finished it yet")
         buffer = StringIO()
         buffer.write(self.download(self.url))
         buffer.seek(0)
@@ -73,24 +84,35 @@
 
 import subprocess
 
+class VCSFetcher(Fetcher):
+    def __init__(self, url, export=True):
+        """
+        - export : whether to strip the versioning information
+        """
+        Fetcher.__init__(self, url)
+        self.export = export
+
 if which('hg'):
 
-    class HgFetcher(Fetcher):
+    class HgFetcher(VCSFetcher):
         """checkout a mercurial repository"""
         type = 'hg'
 
         def __call__(self, dest):
             if os.path.exits(dest):
                 assert os.path.isdir(dest) and os.path.exists(os.path.join(dest, '.hg'))
-            pass # TODO
+            raise NotImplementedError("TODO! Sorry!")
 
     fetchers.append(HgFetcher)
 
 if which('git'):
+
     class GitFetcher(Fetcher):
         """checkout a git repository"""
         type = 'git'
 
+    fetchers
+
 __all__ += [i.__name__ for i in fetchers]
 
 class Fetch(object):
@@ -181,7 +203,7 @@
     parser = optparse.OptionParser(usage=usage, description=__doc__, formatter=PlainDescriptionFormatter())
     parser.add_option('-o', '--output',
                       help="output relative to this location vs. the manifest location")
-    parser.add_option('-d', '--dest',
+    parser.add_option('-d', '--dest', # XXX unused
                       action='append',
                       help="output only these destinations")
     parser.add_option('-s', '--strict',
@@ -193,12 +215,16 @@
     options, args = parser.parse_args(args)
 
     if options.list_fetchers:
-        
-        for name in sorted(fetchers.keys()):
-            print name
+        types = set()
+        for fetcher in fetchers:
+            if fetcher.type in types:
+                continue # occluded, should probably display separately
+            print '%s : %s' % (fetcher.type, fetcher.doc())
+            types.add(fetcher.type)
         parser.exit()
 
     if not args:
+        # TODO: could read from stdin
         parser.print_help()
         parser.exit()