"""Datetime setup useful for IoC usage. Inspired by Dart-quiver's Clock.

The functions and classes of this package are useful when adopting an IoC setup for applications.
The strong dependency of functions and classes on a source of time can be made explicit by using a
Clock class. This can be replaced by a fake in testing, via the fixed function. Or it can be mocked
for even finer grained controls.

The standard usage is:

    import clock

    class Timer(object):
      def __init__(clock):
        self._clock = clock
        self._start = None
        self._end = None

      def start(self):
        self._start = self._clock.now()
        self._end = None

      def end(self):
        self._end = self._clock.now()

      def duration(self):
        return self._start - self._end

    import mockito

    def test_works():
      c = mockito.mock()
      when(c.now).thenReturn(_some_date)
      t = Timer(c)
      t.start()
      when(c.now).thenReturn(_some_other_date)
      t.end()
      assert t.duration == _some_other_date - _some_date
"""

from .clock import fixed
from .clock import Clock

__all__ = []