`chz.field takes the following parameters:
Like with dataclasses, the default value for the field (if any).
Like with dataclasses, a function that returns the default value for the field.
Useful for mutable types, for instance, default_factory=list.
Note: this does not interact with parametrisation / Blueprint / blueprint_unspecified / meta_factory.
The only thing that matters to parametrisation is presence or absence of a
default or default_factory.
Perhaps a better name would be lazy_default (but unfortunately, this is not supported by PEP 681,
so static type checkers would lose the ability to understand the class).
A function or list of functions that validate the field. Field validators take two arguments: the instance of the class and the name of the field.
See also: Validation
If a boolean, whether or not to include the field in the __repr__ of the class.
If a callable, will be used to construct the repr of the field.
The docstring for the field. Used in --help.
Arbitrary user-defined metadata to attach to the field. Useful when extending chz.
Lets you adjust the value of a field. Essentially works the same as an init_property.
See also: Alternative "munging" solution
Useful in combination with mungers. This specifies the type before munging that will be used for parsing and type checking.
A metafactory represents the set of possible callables that can give us a value of a given type.
Describes the set of callables that are capable of returning a valid value for the field if given a non-zero number of arguments.
For instance, the meta factory chz.factories.subclass(Model) is a description of the set of
callables that are capable of producing a Model (e.g. {Transformer, Diffusion}).
This was more useful in previous versions of chz, but now chz infers what you want to do
more reliably.
See also: the docs in chz/factories.py
This is the default callable Blueprint may attempt to call to get a value of the expected type.
See Blueprint
A function that takes a str and returns an object. On failure to cast,
it should raise CastError. Used to achieve custom parsing behaviour from the command
line. Takes priority over the __chz_cast__ dunder method (if present on the
target type).
See also: Casting