[PATCH 1 of 3] templater: implement __len__ for _hybrid

[Anton Shestakov]

# HG changeset patch
# User Anton Shestakov <engored at ya.ru>
# Date 1410174778 -32400
#      Mon Sep 08 20:12:58 2014 +0900
# Node ID 9bb0ab35e90ac9ebf6adbd6e503f3412d9f2adb7
# Parent  5c153c69fdb28ff5b1bf6578e5f07c50bf25833c
templater: implement __len__ for _hybrid

Objects of class _hybrid are returned by such template keywords as children,
bookmarks, tags and others, and also by revset() template function. They are
representing "list of strings" (as hg help template says) for use in templates.
So it would be logical to implement a handy way to count the number of strings
in such list, and that's what __len__ method does.

diff --git a/mercurial/templatekw.py b/mercurial/templatekw.py
--- a/mercurial/templatekw.py
+++ b/mercurial/templatekw.py
@@ -26,6 +26,8 @@ class _hybrid(object):
     def __call__(self):
         for x in self.values:
             yield x
+    def __len__(self):
+        return len(self.values)
 
 def showlist(name, values, plural=None, element=None, **args):
     if not element: