httk.io.cif.cif_parser
======================

.. py:module:: httk.io.cif.cif_parser


Classes
-------

.. autoapisummary::

   httk.io.cif.cif_parser.CifMeta


Functions
---------

.. autoapisummary::

   httk.io.cif.cif_parser.parse_cif_float
   httk.io.cif.cif_parser.parse_cif_int
   httk.io.cif.cif_parser.parse_linear_expr
   httk.io.cif.cif_parser.parse_xyz_op
   httk.io.cif.cif_parser.xyz_symops_to_matrix
   httk.io.cif.cif_parser.parse_asu_cell
   httk.io.cif.cif_parser.parse_structural_modulation
   httk.io.cif.cif_parser.cifblock_to_asu
   httk.io.cif.cif_parser.asus_from_cif_file
   httk.io.cif.cif_parser.single_asu_from_cif_file


Module Contents
---------------

.. py:class:: CifMeta

   Bases: :py:obj:`TypedDict`


   Metadata returned by :func:`parse_cif_float` when ``meta=True``.


   .. py:attribute:: esd
      :type:  float | None


   .. py:attribute:: resolution
      :type:  float


.. py:function:: parse_cif_float(token: str, *, meta: Literal[False] = ..., pragmatic: bool = ...) -> float | None
                 parse_cif_float(token: str, *, meta: Literal[True], pragmatic: bool = ...) -> tuple[float | None, CifMeta]

   Parse a CIF numeric field.

   If meta=False:
       return float_value or None.

   If meta=True:
       return (float_value_or_None, {'esd': esd_or_None, 'resolution': float_resolution}).


.. py:function:: parse_cif_int(token: str, *, strict: bool = True, allow_round: bool = False) -> int

   Convert a CIF numeric token (e.g., '123(4)', '3E2', '1.0E3') to an int using the central value.
   - strict=True: require the value to be exactly integral; otherwise raise ValueError.
   - allow_round=True (only if strict=False): round half-even to the nearest int.


.. py:function:: parse_linear_expr(expr, use_fractions=False)

   expr: e.g. 'x-y', '-z+1/2', 'x', 'y', 'z-1', 'x-2y', '3x+1/2'
   Returns (row, const) where row is [ax, ay, az] (integers or Fractions),
   and const is a float or Fraction depending on use_fractions.


.. py:function:: parse_xyz_op(op, use_fractions=False)

   op: e.g. 'x-y,x,-z+1/2'
   Returns (R, t) where R is 3x3 (list of rows), t is length-3 float list


.. py:function:: xyz_symops_to_matrix(symops_xyz, use_fractions=False)

.. py:function:: parse_asu_cell(cifblock)

.. py:function:: parse_structural_modulation(cifblock)

   Extract structural superspace modulation information from a standard CIF.

   Returns a tuple ``(structural_q, mod_dim, has_struct_mod, struct_mod_atoms)`` where
   ``structural_q`` is a list of q-vectors or ``None``, ``mod_dim`` is the modulation
   dimension (0 if absent), ``has_struct_mod`` is a bool, and ``struct_mod_atoms`` is a
   sorted list of atom-site labels.


.. py:function:: cifblock_to_asu(cifblock, *, return_single=False)

.. py:function:: asus_from_cif_file(fs)

.. py:function:: single_asu_from_cif_file(fs)