namespaces: use namespace object instead of dictionary

namespaces: use namespace object instead of dictionary

This isn't as bad as the diff seems, it only looks like scary. In this patch,
we use the 'namespace' object instead of accessing keys in a dictionary.

This required the 'templatename' and 'names' method to change their
implementation. Later, we will remove these functions entirely due to a better
api.

--- a/mercurial/namespaces.py	Fri Dec 19 17:17:17 2014 -0800
+++ b/mercurial/namespaces.py	Fri Dec 19 17:27:20 2014 -0800
@@ -39,24 +39,27 @@
     def __init__(self):
         self._names = util.sortdict()
 
-        addns = self.addnamespace
+        # shorten the class name for less indentation
+        ns = namespace
 
         # we need current mercurial named objects (bookmarks, tags, and
         # branches) to be initialized somewhere, so that place is here
-        addns("bookmarks", "bookmark",
+        n = ns("bookmarks", "bookmark",
               lambda repo, name: tolist(repo._bookmarks.get(name)),
               lambda repo, name: repo.nodebookmarks(name))
+        self.addnamespace(n)
 
-        addns("tags", "tag",
+        n = ns("tags", "tag",
               lambda repo, name: tolist(repo._tagscache.tags.get(name)),
               lambda repo, name: repo.nodetags(name))
+        self.addnamespace(n)
 
-        addns("branches", "branch",
+        n = ns("branches", "branch",
               lambda repo, name: tolist(repo.branchtip(name)),
               lambda repo, node: [repo[node].branch()])
+        self.addnamespace(n)
 
-    def addnamespace(self, namespace, templatename, namemap, nodemap,
-                     order=None):
+    def addnamespace(self, namespace, order=None):
         """
         register a namespace
 
@@ -67,20 +70,17 @@
         order: optional argument to specify the order of namespaces
                (e.g. 'branches' should be listed before 'bookmarks')
         """
-        val = {'templatename': templatename,
-               'namemap': namemap,
-               'nodemap': nodemap}
         if order is not None:
-            self._names.insert(order, namespace, val)
+            self._names.insert(order, namespace.name, namespace)
         else:
-            self._names[namespace] = val
+            self._names[namespace.name] = namespace
 
         # we only generate a template keyword if one does not already exist
-        if namespace not in templatekw.keywords:
+        if namespace.name not in templatekw.keywords:
             def generatekw(**args):
-                return templatekw.shownames(namespace, **args)
+                return templatekw.shownames(namespace.name, **args)
 
-            templatekw.keywords[namespace] = generatekw
+            templatekw.keywords[namespace.name] = generatekw
 
     def singlenode(self, repo, name):
         """
@@ -91,7 +91,7 @@
         Raises a KeyError if there is no such node.
         """
         for ns, v in self._names.iteritems():
-            n = v['namemap'](repo, name)
+            n = v.namemap(repo, name)
             if n:
                 # return max revision number
                 if len(n) > 1:
@@ -103,12 +103,12 @@
 
     def templatename(self, namespace):
         """method that returns the template name of a namespace"""
-        return self._names[namespace]['templatename']
+        return self._names[namespace].templatename
 
     def names(self, repo, namespace, node):
         """method that returns a (sorted) list of names in a namespace that
         match a given node"""
-        return sorted(self._names[namespace]['nodemap'](repo, node))
+        return sorted(self._names[namespace].nodemap(repo, node))
 
 class namespace(object):
     """provides an interface to a namespace