torch.func
torch.func, previously known as "functorch", is JAX-like composable
function transforms for PyTorch.
Note:
This library is currently in beta. What this means is that the
  features generally work (unless otherwise documented) and we (the
  PyTorch team) are committed to bringing this library forward.
  However, the APIs may change under user feedback and we don't have
  full coverage over PyTorch operations.If you have suggestions on the
  API or use-cases you'd like to be covered, please open an GitHub
  issue or reach out. We'd love to hear about how you're using the
  library.
What are composable function transforms?


A "function transform" is a higher-order function that accepts a
  numerical function and returns a new function that computes a
  different quantity.


"torch.func" has auto-differentiation transforms ("grad(f)" returns
  a function that computes the gradient of "f"), a

