1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
|
from collections.abc import Callable
from typing import TypeVar, overload
from returns.context import NoDeps
from returns.interfaces.failable import DiverseFailableN, SingleFailableN
from returns.methods.cond import internal_cond
from returns.primitives.hkt import Kinded, KindN
_ValueType = TypeVar('_ValueType')
_ErrorType = TypeVar('_ErrorType')
_DiverseFailableKind = TypeVar('_DiverseFailableKind', bound=DiverseFailableN)
_SingleFailableKind = TypeVar('_SingleFailableKind', bound=SingleFailableN)
@overload
def cond(
container_type: type[_SingleFailableKind],
success_value: _ValueType,
) -> Kinded[
Callable[
[bool],
KindN[_SingleFailableKind, _ValueType, _ErrorType, NoDeps],
]
]: ...
@overload
def cond(
container_type: type[_DiverseFailableKind],
success_value: _ValueType,
error_value: _ErrorType,
) -> Kinded[
Callable[
[bool],
KindN[_DiverseFailableKind, _ValueType, _ErrorType, NoDeps],
]
]: ...
def cond(
container_type: (type[_SingleFailableKind] | type[_DiverseFailableKind]),
success_value: _ValueType,
error_value: _ErrorType | None = None,
):
"""
Reduce the boilerplate when choosing paths.
Works with ``SingleFailableN`` (e.g. ``Maybe``)
and ``DiverseFailableN`` (e.g. ``Result``).
Example using ``cond`` with the ``Result`` container:
.. code:: python
>>> from returns.pointfree import cond
>>> from returns.result import Failure, Result, Success
>>> assert cond(Result, 'success', 'failure')(True) == Success('success')
>>> assert cond(Result, 'success', 'failure')(False) == Failure('failure')
Example using ``cond`` with the ``Maybe`` container:
.. code:: python
>>> from returns.maybe import Maybe, Some, Nothing
>>> assert cond(Maybe, 10.0)(True) == Some(10.0)
>>> assert cond(Maybe, 10.0)(False) == Nothing
"""
def factory(is_success: bool): # noqa: FBT001
return internal_cond(
container_type,
is_success,
success_value,
error_value,
)
return factory
|
