dagop: unnest inner generator of revancestors()

This just moves iterate() to module-level function.

mercurial/dagop.py

@@ -20,15 +20,12 b' from . import ('
 baseset = smartset.baseset
 generatorset = smartset.generatorset
 
-def revancestors(repo, revs, followfirst):
-    """Like revlog.ancestors(), but supports followfirst."""
+def _genrevancestors(repo, revs, followfirst):
     if followfirst:
         cut = 1
     else:
         cut = None
     cl = repo.changelog
-
-    def iterate():
         revs.sort(reverse=True)
         irevs = iter(revs)
         h = []
@@ -56,7 +53,10 b' def revancestors(repo, revs, followfirst'
                         if parent.rev() != node.nullrev:
                             heapq.heappush(h, -parent.rev())
 
-    return generatorset(iterate(), iterasc=False)
+def revancestors(repo, revs, followfirst):
+    """Like revlog.ancestors(), but supports followfirst."""
+    gen = _genrevancestors(repo, revs, followfirst)
+    return generatorset(gen, iterasc=False)
 
 def revdescendants(repo, revs, followfirst):
     """Like revlog.descendants() but supports followfirst."""