Source code for kerno.dataclass
"""https://github.com/ericvsmith/dataclasses/blob/master/dataclass_tools.py."""
import dataclasses
[docs]def add_slots(cls):
"""Add __slots__ to a dataclass, making it leaner and faster."""
# Need to create a new class, since we can't set __slots__
# after a class has been created.
# Make sure __slots__ isn't already set.
if "__slots__" in cls.__dict__:
raise TypeError(f"{cls.__name__} already specifies __slots__")
# Create a new dict for our new class.
cls_dict = dict(cls.__dict__)
field_names = tuple(f.name for f in dataclasses.fields(cls))
cls_dict["__slots__"] = field_names
for field_name in field_names:
# Remove our attributes, if present. They'll still be
# available in _MARKER.
cls_dict.pop(field_name, None)
# Remove __dict__ itself.
cls_dict.pop("__dict__", None)
# And finally create the class.
qualname = getattr(cls, "__qualname__", None)
cls = type(cls)(cls.__name__, cls.__bases__, cls_dict)
if qualname is not None:
cls.__qualname__ = qualname
return cls