@dispatch(Broadcast, MongoQuery)
def compute_up(t, q, **kwargs):
    s = t._scalars[0]
    d = dict((s[c], symbol(c, s[c].dshape.measure)) for c in s.fields)
    expr = t._scalar_expr._subs(d)
    name = expr._name or 'expr_%d' % abs(hash(expr))
    return q.append({'$project': {name: compute_sub(expr)}})
dataset/ETHPy150Open blaze/blaze/blaze/compute/mongo.py/compute_up/original