dagop: unnest inner generator of revdescendants()

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

mercurial/dagop.py

@@ -84,14 +84,12 b' def revancestors(repo, revs, followfirst'
     gen = _genrevancestors(repo, revs, followfirst, startdepth, stopdepth)
     return generatorset(gen, iterasc=False)
 
-def revdescendants(repo, revs, followfirst):
-    """Like revlog.descendants() but supports followfirst."""
+def _genrevdescendants(repo, revs, followfirst):
     if followfirst:
         cut = 1
     else:
         cut = None
 
-    def iterate():
         cl = repo.changelog
         # XXX this should be 'parentset.min()' assuming 'parentset' is a
         # smartset (and if it is not, it should.)
@@ -111,7 +109,10 b' def revdescendants(repo, revs, followfir'
                         yield i
                         break
 
-    return generatorset(iterate(), iterasc=True)
+def revdescendants(repo, revs, followfirst):
+    """Like revlog.descendants() but supports followfirst."""
+    gen = _genrevdescendants(repo, revs, followfirst)
+    return generatorset(gen, iterasc=True)
 
 def _reachablerootspure(repo, minroot, roots, heads, includepath):
     """return (heads(::<roots> and ::<heads>))