Refactor offline

This refactoring includes some slicing and performance improvement attempts.

The slicing is still experimental and has some flaws:

• fancy indexing over thousands of elements might be horrible slow, eg f.events.tracks[idx_list, 0] where idx_list is a huge list of indices
• trivial problem of iterating: for track in f.evens.tracks does not stop after the last element
• meaningless indexing: f.events[5][23][420] is simply f.events[420] since the index/slice is not chained but overwritten when propagated. We need custom checks whether it makes sense
  • events are flat lists, so [x][y] does not make sense, it should throw an error
  • f.events[5:23][4] should effectively be the same as f.events[9] due to chaining of slice/index

tests/test_offline.py

@@ -250,6 +250,7 @@ class TestOfflineHits(unittest.TestCase):
 
 class TestOfflineTracks(unittest.TestCase):
     def setUp(self):
+        self.f = OFFLINE_FILE
         self.tracks = OFFLINE_FILE.events.tracks
         self.tracks_numucc = OFFLINE_NUMUCC
         self.n_events = 10
@@ -291,6 +292,20 @@ class TestOfflineTracks(unittest.TestCase):
             self.assertListEqual(list(tracks.E[:, 0][_slice]),
                                  list(tracks[_slice].E[:, 0]))
 
+    def test_nested_indexing(self):
+        self.assertAlmostEqual(
+            self.f.events.tracks.fitinf[3:5][1][9][2],
+            self.f.events[3:5].tracks[1].fitinf[9][2])
+        self.assertAlmostEqual(
+            self.f.events.tracks.fitinf[3:5][1][9][2],
+            self.f.events[3:5][1][9][2].tracks.fitinf)
+        self.assertAlmostEqual(
+            self.f.events.tracks.fitinf[3:5][1][9][2],
+            self.f.events[3:5][1].tracks[9][2].fitinf)
+        self.assertAlmostEqual(
+            self.f.events.tracks.fitinf[3:5][1][9][2],
+            self.f.events[3:5][1].tracks[9].fitinf[2])
+
 
 
 class TestBranchIndexingMagic(unittest.TestCase):