def _ReplaceSlicesWithTuples(self, idx):
    """Helper method to replace slices with tuples for dynamic indexing args."""
    if isinstance(idx, slice):
      triple = idx.start, idx.stop, idx.step
      isnone = [i for i, elt in enumerate(triple) if elt is None]
      zeros = itertools.repeat(0)
      nones = itertools.repeat(None)
      out = subvals(triple, zip(isnone, zeros))
      return out, lambda out: slice(*subvals(out, zip(isnone, nones)))
    elif isinstance(idx, (tuple, list)) and idx:
      t = type(idx)
      elts, packs = zip(*map(self._ReplaceSlicesWithTuples, idx))
      return elts, lambda elts: t((pack(i) for pack, i in zip(packs, elts)))
    else:
      return idx, lambda x: x
Helper method to replace slices with tuples for dynamic indexing args.
trax/tf_numpy/jax_tests/lax_numpy_indexing_test.py