Points from Jim Pivarski in person ( to be split up later)

From real-time discussions with @jpivarski, to be split up / reprocessed later.

• expressions (numpexr) should first call awkward.compact() then check array offsets are the same, which will increase functionality and safety of checks.

def sanitize(a):
   a = a.compact()
   a = a[a.starts[0]: a.stops[-1]]

• jagged._broadcast(data) can help broadcast arrays first to feed in to numexpr
• Can we use numexpr to pre-parse expressions to get the full list of necessary branches / variables