partition_static
================

.. py:function:: t3toolbox.backend.common.partition_static(tree)

   .. code-block:: python

      def partition_static(
              tree,   # a tuple/list tree of arrays and static structure (a frame's .data, a frame sweep, ...)
      ) -> typ.Tuple[
          typ.Tuple,        # the dynamic leaves, in traversal order -- the jax pytree children
          StaticSkeleton,   # the tree shape + static values -- the jax pytree aux_data
      ]:


   Split a raw backend data tuple into what jax should TRACE and what it must keep STATIC.

   Backend data tuples mix both -- a uniform frame is ``(4 supercores, shape, masks)`` -- and a bare
   tuple is a jax pytree whose every element is a leaf, so flattening one naively traces the masks and
   the shape. That raises (``require_concrete_masks``) or silently produces a program that cannot do
   host-integer shape arithmetic. The frontend avoids it by giving ``UT3Frame`` a registered pytree with
   the masks as aux; the backend keeps plain tuples, so the split happens here instead.

   Round-trips exactly through :py:func:`rebuild_static`.