[PATCH 2 of 8] namespaces: add a method to register new namespaces

[Sean Farley]

# HG changeset patch
# User Sean Farley <sean.michael.farley at gmail.com>
# Date 1413570351 25200
#      Fri Oct 17 11:25:51 2014 -0700
# Node ID 98bc28635ee1999c778e5c98f55423147d316a9e
# Parent  eb7489c4b2f83efcfbeca4c3b68022bd5596e352
namespaces: add a method to register new namespaces

diff --git a/mercurial/namespaces.py b/mercurial/namespaces.py
--- a/mercurial/namespaces.py
+++ b/mercurial/namespaces.py
@@ -32,5 +32,29 @@ class namespaces(object):
 
     _names_version = 0
 
     def __init__(self):
         self._names = util.sortdict()
+
+    def addnamespace(self, namespace, singular, names, namemap, nodemap,
+                     order=None):
+        """
+        register a namespace
+
+        namespace: the name to be registered (in plural form)
+        singular: the singular naming of namespace (for output, e.g. log,
+                  templating, etc.)
+        names: function to list all names
+        namemap: function that inputs a node, output name(s)
+        nodemap: function that inputs a name, output node(s)
+        order: optional argument to specify the order of namespaces
+               (e.g. 'branches' should be listed before 'bookmarks')
+
+        """
+        val = {'singular': singular,
+               'names': names,
+               'namemap': namemap,
+               'nodemap': nodemap}
+        if order is not None:
+            self._names.insert(order, namespace, val)
+        else:
+            self._names[namespace] = val