Skip to content

Utilities API

eaterate.Option

Bases: Generic[T]

Represents optional data.

If no data present:

Option.none()

If data is present:

Option.some(some_data)
Source code in eaterate/option.py 
  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
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
class Option(Generic[T]):
    """Represents optional data.

    If no data present:

    ```python
    Option.none()
    ```

    If data is present:

    ```python
    Option.some(some_data)
    ```
    """

    __slots__ = ("__data", "__has")

    __data: Optional[T]
    __has: bool

    def __init__(self, d: Optional[T], h: bool):
        self.__data = d
        self.__has = h

    @staticmethod
    def none() -> "Option[T]":
        """Creates Option 'none' (`__NONE__`)"""
        return __NONE__

    @staticmethod
    def some(d: T) -> "Option[T]":
        """Creates Option 'some'

        Args:
            d: The data.
        """
        return Option(d, True)

    def is_none(self) -> bool:
        """Checks if there's no data.

        Example:
            ```python
            one = Option.some("hello, world!")
            print(one.is_none())  # False

            two = Option.none()
            print(two.is_none())  # True
            ```
        """
        return not self.__has

    def is_some(self) -> bool:
        """Checks if there's data.

        Example:
            ```python
            one = Option.some("hello, world!")
            print(one.is_some())  # True

            two = Option.none()
            print(two.is_some())  # False
            ```
        """
        return self.__has

    def _unwrap(self) -> T:
        """(unsafe)

        Unwraps this item without checking.

        Warning:
            This function does not raise a `RuntimeError` if no data is
            present. Unless it's known, do not use this function as it
            causes undefined behavior.
        """
        return self.__data  # type: ignore

    def unwrap(self) -> T:
        """Unwraps the data.

        Raises:
            RuntimeError: If no data is present (instance is `Option.none()`), this is raised.
        """
        if self.__has:
            return self.__data  # type: ignore
        else:
            raise RuntimeError("cannot call unwrap on Option 'none'")

    def unwrap_or(self, alternative: T, /) -> T:
        """Unwraps the data or use an alternative value.

        Example:
            ```python
            # Since there is data, it just unwraps
            # the original one.
            foo = Option.some("hello")
            print(foo.unwrap_or("world"))  # hello

            # Since there is NO data, it uses the
            # alternative value.
            bar = Option.none()
            print(bar.unwrap_or("world"))  # world
            ```

        Args:
            alternative: The alternative value.
        """
        if self.__has:
            return self.__data  # type: ignore
        else:
            return alternative

    def replace(self, x: T, /) -> None:
        """Replaces the current data for this instance.

        Example:
            ```python
            one = Option.some(69)
            one.replace(420)
            print(one)  # Some(420)

            two = Option.none()
            two.replace(420)
            print(two)  # Some(420)
            ```

        Returns:
            None: Nothing is returned.
        """
        self.__has = True
        self.__data = x

    def map(self, fn: Callable[[T], K], /) -> "Option[K]":
        if self.is_some():
            return Option.some(fn(self.__data))  # type: ignore
        else:
            return self  # type: ignore

    def __hash__(self) -> int:
        return 0

    def __bool__(self) -> bool:
        return False

    def __str__(self) -> str:
        if self.__has:
            return f"Some({self.__data!r})"
        else:
            return "Option.none()"

    def __repr__(self) -> str:
        return self.__str__()

_unwrap()

(unsafe)

Unwraps this item without checking.

Warning

This function does not raise a RuntimeError if no data is present. Unless it's known, do not use this function as it causes undefined behavior.

Source code in eaterate/option.py 
74
75
76
77
78
79
80
81
82
83
84
def _unwrap(self) -> T:
    """(unsafe)

    Unwraps this item without checking.

    Warning:
        This function does not raise a `RuntimeError` if no data is
        present. Unless it's known, do not use this function as it
        causes undefined behavior.
    """
    return self.__data  # type: ignore

is_none()

Checks if there's no data.

Example 
one = Option.some("hello, world!")
print(one.is_none())  # False

two = Option.none()
print(two.is_none())  # True
Source code in eaterate/option.py 
46
47
48
49
50
51
52
53
54
55
56
57
58
def is_none(self) -> bool:
    """Checks if there's no data.

    Example:
        ```python
        one = Option.some("hello, world!")
        print(one.is_none())  # False

        two = Option.none()
        print(two.is_none())  # True
        ```
    """
    return not self.__has

is_some()

Checks if there's data.

Example 
one = Option.some("hello, world!")
print(one.is_some())  # True

two = Option.none()
print(two.is_some())  # False
Source code in eaterate/option.py 
60
61
62
63
64
65
66
67
68
69
70
71
72
def is_some(self) -> bool:
    """Checks if there's data.

    Example:
        ```python
        one = Option.some("hello, world!")
        print(one.is_some())  # True

        two = Option.none()
        print(two.is_some())  # False
        ```
    """
    return self.__has

none() staticmethod

Creates Option 'none' (__NONE__)

Source code in eaterate/option.py 
32
33
34
35
@staticmethod
def none() -> "Option[T]":
    """Creates Option 'none' (`__NONE__`)"""
    return __NONE__

replace(x)

Replaces the current data for this instance.

Example 
one = Option.some(69)
one.replace(420)
print(one)  # Some(420)

two = Option.none()
two.replace(420)
print(two)  # Some(420)

Returns:

Name Type Description
None None

Nothing is returned.
Source code in eaterate/option.py 
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
def replace(self, x: T, /) -> None:
    """Replaces the current data for this instance.

    Example:
        ```python
        one = Option.some(69)
        one.replace(420)
        print(one)  # Some(420)

        two = Option.none()
        two.replace(420)
        print(two)  # Some(420)
        ```

    Returns:
        None: Nothing is returned.
    """
    self.__has = True
    self.__data = x

some(d) staticmethod

Creates Option 'some'

Parameters:

Name Type Description Default
d T

The data.

 required
Source code in eaterate/option.py 
37
38
39
40
41
42
43
44
@staticmethod
def some(d: T) -> "Option[T]":
    """Creates Option 'some'

    Args:
        d: The data.
    """
    return Option(d, True)

unwrap()

Unwraps the data.

Raises:

Type Description
RuntimeError

If no data is present (instance is Option.none()), this is raised.
Source code in eaterate/option.py 
86
87
88
89
90
91
92
93
94
95
def unwrap(self) -> T:
    """Unwraps the data.

    Raises:
        RuntimeError: If no data is present (instance is `Option.none()`), this is raised.
    """
    if self.__has:
        return self.__data  # type: ignore
    else:
        raise RuntimeError("cannot call unwrap on Option 'none'")

unwrap_or(alternative)

Unwraps the data or use an alternative value.

Example 
# Since there is data, it just unwraps
# the original one.
foo = Option.some("hello")
print(foo.unwrap_or("world"))  # hello

# Since there is NO data, it uses the
# alternative value.
bar = Option.none()
print(bar.unwrap_or("world"))  # world

Parameters:

Name Type Description Default
alternative T

The alternative value.

 required
Source code in eaterate/option.py 
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
def unwrap_or(self, alternative: T, /) -> T:
    """Unwraps the data or use an alternative value.

    Example:
        ```python
        # Since there is data, it just unwraps
        # the original one.
        foo = Option.some("hello")
        print(foo.unwrap_or("world"))  # hello

        # Since there is NO data, it uses the
        # alternative value.
        bar = Option.none()
        print(bar.unwrap_or("world"))  # world
        ```

    Args:
        alternative: The alternative value.
    """
    if self.__has:
        return self.__data  # type: ignore
    else:
        return alternative