Function _reverse_range

ormar/queryset/utils.py:290–312

Handles ``[-A:-B]`` (both bounds negative). Out-of-order bounds (``start >= stop``, e.g. ``[-2:-5]``) clamp to empty; otherwise the slice is emulated by flipping the ORDER BY, offsetting ``|stop|`` rows from the end, and limiting to ``|start| - |stop|`` rows. Examples::

(start: int, stop: int)

def _reverse_range(start: int, stop: int) -> SliceBounds:
    """
    Handles ``[-A:-B]`` (both bounds negative). Out-of-order bounds
    (``start >= stop``, e.g. ``[-2:-5]``) clamp to empty; otherwise the
    slice is emulated by flipping the ORDER BY, offsetting ``|stop|`` rows
    from the end, and limiting to ``|start| - |stop|`` rows.

    Examples::

        [-5:-2] → SliceBounds(limit=3, offset=2, reverse=True)
        [-3:-1] → SliceBounds(limit=2, offset=1, reverse=True)
        [-2:-5] → SliceBounds(limit=0, offset=0, reverse=True)  # empty

    :param start: negative lower bound
    :type start: int
    :param stop: negative upper bound
    :type stop: int
    :return: ``SliceBounds(..., reverse=True)``
    :rtype: SliceBounds
    """
    if start >= stop:
        return SliceBounds(limit=0, offset=0, reverse=True)
    return SliceBounds(limit=stop - start, offset=-stop, reverse=True)


def translate_list_to_dict(  # noqa: CCR001