[PATCH] manifest: add matches() method

[Martin von Zweigbergk]

# HG changeset patch
# User Martin von Zweigbergk <martinvonz at google.com>
# Date 1414039110 25200
#      Wed Oct 22 21:38:30 2014 -0700
# Node ID 36e990ef2fc4c96fac15052f0fbb05d1a96bd616
# Parent  394c79df66c39923477528b2ea2092b6944b965b
manifest: add matches() method

Move the code in context._manifestmatches() into a new
manifest.matches(). It's a natural place for the code to live and it
allows other callers to easily use it. It should also make it easier
to optimize the new method in alternative implementations of the
manifest (same reasoning as with manifest.diff()).

diff --git a/mercurial/context.py b/mercurial/context.py
--- a/mercurial/context.py
+++ b/mercurial/context.py
@@ -71,19 +71,7 @@
         object oriented way for other contexts to customize the manifest
         generation.
         """
-        if match.always():
-            return self.manifest().copy()
-
-        files = match.files()
-        if (match.matchfn == match.exact or
-            (not match.anypats() and util.all(fn in self for fn in files))):
-            return self.manifest().intersectfiles(files)
-
-        mf = self.manifest().copy()
-        for fn in mf.keys():
-            if not match(fn):
-                del mf[fn]
-        return mf
+        return self.manifest().matches(match)
 
     def _matchstatus(self, other, match):
         """return match.always if match is none
diff --git a/mercurial/manifest.py b/mercurial/manifest.py
--- a/mercurial/manifest.py
+++ b/mercurial/manifest.py
@@ -39,6 +39,22 @@
                     ret._flags[fn] = flags
         return ret
 
+    def matches(self, match):
+        '''generate a new manifest filtered by the match argument'''
+        if match.always():
+            return self.copy()
+
+        files = match.files()
+        if (match.matchfn == match.exact or
+            (not match.anypats() and util.all(fn in self for fn in files))):
+            return self.intersectfiles(files)
+
+        mf = self.copy()
+        for fn in mf.keys():
+            if not match(fn):
+                del mf[fn]
+        return mf
+
     def diff(self, m2):
         '''Finds changes between the current manifest and m2. The result is
         returned as a dict with filename as key and values of the form