"""
Types shared across multiple submodules
"""
import numpy
from typing import List, Callable


# Field types
field_t = numpy.ndarray        # vector field with shape (3, X, Y, Z) (e.g. [E_x, E_y, E_z])
vfield_t = numpy.ndarray       # linearized vector field (vector of length 3*X*Y*Z)

'''
 'dxes' datastructure which contains grid cell width information in the following format:
 [[[dx_e_0, dx_e_1, ...], [dy_e_0, ...], [dz_e_0, ...]],
  [[dx_h_0, dx_h_1, ...], [dy_h_0, ...], [dz_h_0, ...]]]
 where dx_e_0 is the x-width of the x=0 cells, as used when calculating dE/dx,
 and dy_h_0 is  the y-width of the y=0 cells, as used when calculating dH/dy, etc.
'''
dx_lists_t = List[List[numpy.ndarray]]


field_updater = Callable[[field_t], field_t]