rberga06.utils.types.Mut#

final class rberga06.utils.types.Mut(value: _T, /)#

Bases: Generic[_T], SupportsPydanticV2[Mut[_T] | _T]

Flexible, static, mutable strong reference to a value.

Example:

>>> # Immutable data
>>> data = 42
>>> m0 = Mut(data)
>>> m1 = m0
>>> m2 = Mut(data)
>>> m0 is m1
True
>>> m0 is m2
False
>>> print(m0, m1, m2)
Mut(42) Mut(42) Mut(42)
>>> m0._ = 69
>>> print(m0, m1, m2)
Mut(69) Mut(69) Mut(42)
>>>
>>> # Mutable data
>>> data = [42]
>>> m0 = Mut(data)
>>> m1 = m0
>>> m2 = Mut(data)
>>> m3 = Mut(data.copy())
>>> m0 is m1
True
>>> m0 is m2
False
>>> m0 is m3
False
>>> print(m0, m1, m2, m3)
Mut([42]) Mut([42]) Mut([42]) Mut([42])
>>> m0._[0] = 33
>>> print(m0, m1, m2, m3)
Mut([33]) Mut([33]) Mut([33]) Mut([42])
>>> m0._ = [69]
>>> print(m0, m1, m2, m3)
Mut([69]) Mut([69]) Mut([33]) Mut([42])

Mut is most useful when you need to pass around an immutable piece of data (like, in the example, int instances), without bothering to use a full list, where data access might be less readable and more error-prone - compare (l := [42])[0] with (m := Mut(42)).value…

Mut can also be used as a Pydantic model field, because it implements SupportsPydanticV2.

Caution

Nesting Mut instances (for example, Mut(Mut(42))) is possible, but strongly discouraged. There are two reasons for this:

There is no use case for this. If an object is already a Mut, why wrapping it _again_ into a Mut? To get the exact same behaviour the object already has?
The Pydantic compatibility API (see SupportsPydanticV2) is designed to allow the following:
```
>>> Mut[int].validate(42)
Mut(42)
>>> Mut[int].validate(Mut(42))
Mut(42)
```
It’s not yet possible to access bound type parameters at runtime with consistency (see https://github.com/python/typing/issues/629); this means it’s impossible to distinguish between these two calls:
```
>>> Mut[int].validate(Mut(42))
Mut(42)
>>> Mut[Mut[int]].validate(Mut(42))
Mut(42)
```

__init__(value: _T, /) → None#

Methods

`__init__`(value, /)
`get`()	Get the inner value.
`set`(value, /)	Set the inner value.
`validate`(obj)	Instantiate this class from `obj`.

Attributes

value

The inner value.

get() → _T#: Get the inner value.

set(value: _T, /) → None#: Set the inner value.

classmethod validate(obj: Mut[_T] | _T) → Self#: Instantiate this class from obj.

value: _T#: The inner value. Also accessible via the _ property.