trcks.oop

Example

This example uses the classes Wrapper and ResultWrapper to create and further process a value of type trcks.Result:

>>> import enum
>>> import math
>>> from trcks import Result
>>> from trcks.oop import Wrapper
>>> class GetSquareRootError(enum.Enum):
...     NEGATIVE_INPUT = enum.auto()
...
>>> def get_square_root(x: float) -> Result[GetSquareRootError, float]:
...     return (
...         Wrapper(core=x)
...         .map_to_result(
...             lambda x: ("success", x)
...             if x >= 0
...             else ("failure", GetSquareRootError.NEGATIVE_INPUT)
...         )
...         .map_success(math.sqrt)
...         .core
...     )
...
>>> get_square_root(25.0)
('success', 5.0)
>>> get_square_root(-25.0)
('failure', <GetSquareRootError.NEGATIVE_INPUT: 1>)

Variable and type assignments for intermediate values might help to clarify what is going on:

>>> import enum
>>> import math
>>> from trcks import Result
>>> from trcks.oop import ResultWrapper, Wrapper
>>> class GetSquareRootError(enum.Enum):
...     NEGATIVE_INPUT = enum.auto()
...
>>> def get_square_root(x: float) -> Result[GetSquareRootError, float]:
...     wrapper: Wrapper[float] = Wrapper(core=x)
...     result_wrapper: ResultWrapper[
...         GetSquareRootError, float
...     ] = wrapper.map_to_result(
...         lambda x: ("success", x)
...         if x >= 0
...         else ("failure", GetSquareRootError.NEGATIVE_INPUT)
...     )
...     mapped_result_wrapper: ResultWrapper[GetSquareRootError, float] = (
...         result_wrapper.map_success(math.sqrt)
...     )
...     result: Result[GetSquareRootError, float] = mapped_result_wrapper.core
...     return result
...
>>> get_square_root(25.0)
('success', 5.0)
>>> get_square_root(-25.0)
('failure', <GetSquareRootError.NEGATIVE_INPUT: 1>)