Source code for returns.interfaces.specific.result

An interface that represents a pure computation result.

For impure result see
:class:`returns.interfaces.specific.ioresult.IOResultLikeN` type.

from __future__ import annotations

from abc import abstractmethod
from typing import TYPE_CHECKING, Callable, NoReturn, Type, TypeVar

from returns.interfaces import equable, failable, unwrappable
from import KindN

    from returns.result import Result  # noqa: WPS433

_FirstType = TypeVar('_FirstType')
_SecondType = TypeVar('_SecondType')
_ThirdType = TypeVar('_ThirdType')
_UpdatedType = TypeVar('_UpdatedType')

_ResultLikeType = TypeVar('_ResultLikeType', bound='ResultLikeN')

# New values:
_ValueType = TypeVar('_ValueType')
_ErrorType = TypeVar('_ErrorType')

# Unwrappable:
_FirstUnwrappableType = TypeVar('_FirstUnwrappableType')
_SecondUnwrappableType = TypeVar('_SecondUnwrappableType')

[docs]class ResultLikeN( failable.DiverseFailableN[_FirstType, _SecondType, _ThirdType], ): """ Base types for types that looks like ``Result`` but cannot be unwrapped. Like ``RequiresContextResult`` or ``FutureResult``. """
[docs] @abstractmethod def bind_result( self: _ResultLikeType, function: Callable[[_FirstType], 'Result[_UpdatedType, _SecondType]'], ) -> KindN[_ResultLikeType, _UpdatedType, _SecondType, _ThirdType]: """Runs ``Result`` returning function over a container."""
[docs] @classmethod @abstractmethod def from_result( cls: Type[_ResultLikeType], # noqa: N805 inner_value: 'Result[_ValueType, _ErrorType]', ) -> KindN[_ResultLikeType, _ValueType, _ErrorType, _ThirdType]: """Unit method to create new containers from any raw value."""
#: Type alias for kinds with two type arguments. ResultLike2 = ResultLikeN[_FirstType, _SecondType, NoReturn] #: Type alias for kinds with three type arguments. ResultLike3 = ResultLikeN[_FirstType, _SecondType, _ThirdType]
[docs]class UnwrappableResult( ResultLikeN[_FirstType, _SecondType, _ThirdType], unwrappable.Unwrappable[_FirstUnwrappableType, _SecondUnwrappableType], equable.Equable, ): """ Intermediate type with 5 type arguments that represents unwrappable result. It is a raw type and should not be used directly. Use ``ResultBasedN`` and ``IOResultBasedN`` instead. """
[docs]class ResultBasedN( UnwrappableResult[ _FirstType, _SecondType, _ThirdType, # Unwraps: _FirstType, _SecondType, ], ): """ Base type for real ``Result`` types. Can be unwrapped. """
#: Type alias for kinds with two type arguments. ResultBased2 = ResultBasedN[_FirstType, _SecondType, NoReturn] #: Type alias for kinds with three type arguments. ResultBased3 = ResultBasedN[_FirstType, _SecondType, _ThirdType]