Fixed - [1](https://github.com/AlexandreDecan/portion/issues/1) by making empty intervals always resolving to `(P.inf, -P.inf)`.
1.5.0
Added - `Interval.__init__` accepts `Interval` instances in addition to `AtomicInterval` ones.
1.4.0
Added - Function `P.to_string` to export an interval to a string, with many options to customize the representation. - Function `P.from_string` to create an interval from a string, with many options to customize the parsing.
1.3.2
Added - Support for Python 2.7.
1.3.1
Fixed - More tests to cover all comparisons. - Define `__slots__` to lower memory usage, and to speed up attribute access. - Define `Interval.__rand__` (and other magic methods) to support `Interval` from `AtomicInterval` instead of having a dedicated piece of code in `AtomicInterval`. - `__all__` properly defined.
1.3.0
Added - Meaningful `<=` and `>=` comparisons for intervals.