use 'x is None' instead of 'x == None'
The built-in None object is a singleton and it is therefore safe to
compare memory addresses with is. It is also faster, how much depends
on the object being compared. For a simple type like str I get:
| s = "foo" | s = None
----------+-----------+----------
s == None | 0.25 usec | 0.21 usec
s is None | 0.17 usec | 0.17 usec
% initialize darcs repo
Finished recording patch 'p0'
% branch and update
Finished recording patch 'p1.1'
% update source
Finished recording patch 'p1.2'
% merge branch
We have conflicts in the following files:
./a
Finished pulling and applying.
Finished recording patch 'p2'
initializing destination darcs-repo-hg repository
scanning source...
sorting...
converting...
3 p0
2 p1.2
1 p1.1
0 p2
o 3 "p2" files: a
|
o 2 "p1.1" files:
|
o 1 "p1.2" files: a b
|
o 0 "p0" files: a
7225b30cdf38257d5cc7780772c051b6f33e6d6b 644 a
1e88685f5ddec574a34c70af492f95b6debc8741 644 b