Null

Bases: OptionType[T]

              flowchart TD
              pyochain.core._option.Null[Null]
              pyochain.core._option.OptionType[OptionType]
              pyochain.abc._mixins.Pipe[Pipe]

                              pyochain.core._option.OptionType --> pyochain.core._option.Null
                                pyochain.abc._mixins.Pipe --> pyochain.core._option.OptionType
                



              click pyochain.core._option.Null href "" "pyochain.core._option.Null"
              click pyochain.core._option.OptionType href "" "pyochain.core._option.OptionType"
              click pyochain.abc._mixins.Pipe href "" "pyochain.abc._mixins.Pipe"
            

Option variant representing the absence of a value.

This class or NONE can be used interchangeably, as calling Null() will always return the singleton instance NONE.

For pattern matching, you must use Null, as NONE isn't special cased by type checkers the same way python None is, and thus can't be narrowed to Null.

For more documentation, see the Option[T] class.

from pyochain import Null, NONE, Some, Option

assert Null() is NONE

def is_none(x: Option[int]) -> bool:
    match x:
        case Null():
            return True
        case Some(_):
            return False

assert is_none(NONE)
assert not is_none(Some(42))
assert is_none(Null())

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@final
class Null[T = Any](OptionType[T]):
    """Option variant representing the absence of a value.

    This class or `NONE` can be used interchangeably, as calling `Null()` will always return the singleton instance `NONE`.

    For pattern matching, you must use `Null`, as `NONE` isn't special cased by type checkers the same way python `None` is, and thus can't be narrowed to `Null`.

    For more documentation, see the `Option[T]` class.

    Example:
        ```python
        from pyochain import Null, NONE, Some, Option

        assert Null() is NONE

        def is_none(x: Option[int]) -> bool:
            match x:
                case Null():
                    return True
                case Some(_):
                    return False

        assert is_none(NONE)
        assert not is_none(Some(42))
        assert is_none(Null())
        ```
    """
    def __new__(cls) -> Option[T]: ...