Make KeywordOnly an Enum

And make Hashability public

Author: hynek

src/attr/_make.py

@@ -103,7 +103,7 @@ def __reduce__(self, _none_constructor=type(None), _args=()):  # noqa: B008
         return _none_constructor, _args
 
 
-class _Hashability(enum.Enum):
+class Hashability(enum.Enum):
     """
     The hashability of a class.
     """
@@ -113,6 +113,16 @@ class _Hashability(enum.Enum):
     LEAVE_ALONE = "leave_alone"  # don't touch __hash__
 
 
+class KeywordOnly(enum.Enum):
+    """
+    How attributes should be treated regarding keyword-only parameters.
+    """
+
+    NO = "no"  # attributes are not keyword-only
+    YES = "yes"  # attributes in current class without kw_only=False are keyword-only
+    FORCE = "force"  # all attributes are keyword-only
+
+
 class ClassProps(NamedTuple):
     """
     Effective class properties as derived from parameters to attr.s() or
@@ -125,14 +135,13 @@ class ClassProps(NamedTuple):
     is_slotted: bool
     has_weakref_slot: bool
     is_frozen: bool
-    is_kw_only: bool
-    force_kw_only: bool
+    kw_only: KeywordOnly
     collect_by_mro: bool
     init: bool
     repr: bool
     eq: bool
     order: bool
-    hash: _Hashability
+    hash: Hashability
     cache_hash: bool
     match_args: bool
     str: bool
@@ -419,7 +428,6 @@ def _transform_attrs(
     these,
     auto_attribs,
     kw_only,
-    force_kw_only,
     collect_by_mro,
     field_transformer,
 ) -> _Attributes:
@@ -477,7 +485,7 @@ def _transform_attrs(
 
     fca = Attribute.from_counting_attr
     own_attrs = [
-        fca(attr_name, ca, kw_only, anns.get(attr_name))
+        fca(attr_name, ca, kw_only is not KeywordOnly.NO, anns.get(attr_name))
         for attr_name, ca in ca_list
     ]
 
@@ -490,7 +498,7 @@ def _transform_attrs(
             cls, {a.name for a in own_attrs}
         )
 
-    if kw_only and force_kw_only:
+    if kw_only is KeywordOnly.FORCE:
         own_attrs = [a.evolve(kw_only=True) for a in own_attrs]
         base_attrs = [a.evolve(kw_only=True) for a in base_attrs]
 
@@ -708,8 +716,7 @@ def __init__(
             cls,
             these,
             auto_attribs,
-            props.is_kw_only,
-            props.force_kw_only,
+            props.kw_only,
             props.collect_by_mro,
             props.field_transformer,
         )
@@ -1481,28 +1488,33 @@ def wrap(cls):
         )
 
         if is_exc:
-            hashability = _Hashability.LEAVE_ALONE
+            hashability = Hashability.LEAVE_ALONE
         elif hash is True:
-            hashability = _Hashability.HASHABLE
+            hashability = Hashability.HASHABLE
         elif hash is False:
-            hashability = _Hashability.LEAVE_ALONE
+            hashability = Hashability.LEAVE_ALONE
         elif hash is None:
             if auto_detect is True and _has_own_attribute(cls, "__hash__"):
-                hashability = _Hashability.LEAVE_ALONE
+                hashability = Hashability.LEAVE_ALONE
             elif eq is True and is_frozen is True:
-                hashability = _Hashability.HASHABLE
+                hashability = Hashability.HASHABLE
             elif eq is False:
-                hashability = _Hashability.LEAVE_ALONE
+                hashability = Hashability.LEAVE_ALONE
             else:
-                hashability = _Hashability.UNHASHABLE
+                hashability = Hashability.UNHASHABLE
         else:
             msg = "Invalid value for hash.  Must be True, False, or None."
             raise TypeError(msg)
 
-        if hashability is not _Hashability.HASHABLE and cache_hash:
+        if hashability is not Hashability.HASHABLE and cache_hash:
             msg = "Invalid value for cache_hash.  To use hash caching, hashing must be either explicitly or implicitly enabled."
             raise TypeError(msg)
 
+        if kw_only:
+            kwo = KeywordOnly.YES if not force_kw_only else KeywordOnly.FORCE
+        else:
+            kwo = KeywordOnly.NO
+
         props = ClassProps(
             is_exception=is_exc,
             is_frozen=is_frozen,
@@ -1524,8 +1536,7 @@ def wrap(cls):
             ),
             hash=hashability,
             match_args=match_args,
-            is_kw_only=kw_only,
-            force_kw_only=force_kw_only,
+            kw_only=kwo,
             has_weakref_slot=weakref_slot,
             cache_hash=cache_hash,
             str=str,
@@ -1562,9 +1573,9 @@ def wrap(cls):
         if not frozen:
             builder.add_setattr()
 
-        if props.hash is _Hashability.HASHABLE:
+        if props.hash is Hashability.HASHABLE:
             builder.add_hash()
-        elif props.hash is _Hashability.UNHASHABLE:
+        elif props.hash is Hashability.UNHASHABLE:
             builder.make_unhashable()
 
         if props.init:

tests/test_make.py

@@ -28,14 +28,15 @@
     Attribute,
     ClassProps,
     Factory,
+    Hashability,
+    KeywordOnly,
     _AndValidator,
     _Attributes,
     _ClassBuilder,
     _CountingAttr,
     _determine_attrib_eq_order,
     _determine_attrs_eq_order,
     _determine_whether_to_implement,
-    _Hashability,
     _transform_attrs,
     and_,
     fields,
@@ -183,7 +184,7 @@ def test_no_modifications(self):
         Does not attach __attrs_attrs__ to the class.
         """
         C = make_tc()
-        _transform_attrs(C, None, False, False, False, True, None)
+        _transform_attrs(C, None, False, KeywordOnly.NO, True, None)
 
         assert None is getattr(C, "__attrs_attrs__", None)
 
@@ -193,7 +194,7 @@ def test_normal(self):
         """
         C = make_tc()
         attrs, _, _ = _transform_attrs(
-            C, None, False, False, False, True, None
+            C, None, False, KeywordOnly.NO, True, None
         )
 
         assert ["z", "y", "x"] == [a.name for a in attrs]
@@ -208,7 +209,7 @@ class C:
             pass
 
         assert _Attributes((), [], {}) == _transform_attrs(
-            C, None, False, False, False, True, None
+            C, None, False, KeywordOnly.NO, True, None
         )
 
     def test_transforms_to_attribute(self):
@@ -217,7 +218,7 @@ def test_transforms_to_attribute(self):
         """
         C = make_tc()
         attrs, base_attrs, _ = _transform_attrs(
-            C, None, False, False, False, True, None
+            C, None, False, KeywordOnly.NO, True, None
         )
 
         assert [] == base_attrs
@@ -235,7 +236,7 @@ class C:
             y = attr.ib()
 
         with pytest.raises(ValueError) as e:
-            _transform_attrs(C, None, False, False, False, True, None)
+            _transform_attrs(C, None, False, KeywordOnly.NO, True, None)
         assert (
             "No mandatory attributes allowed after an attribute with a "
             "default value or factory.  Attribute in question: Attribute"
@@ -264,7 +265,7 @@ class C(B):
             y = attr.ib()
 
         attrs, base_attrs, _ = _transform_attrs(
-            C, None, False, True, False, True, None
+            C, None, False, KeywordOnly.YES, True, None
         )
 
         assert len(attrs) == 3
@@ -280,8 +281,7 @@ class C(B):
             C,
             None,
             False,
-            True,
-            True,  # force kw-only
+            KeywordOnly.FORCE,
             True,
             None,
         )
@@ -307,7 +307,7 @@ class C(Base):
             y = attr.ib()
 
         attrs, base_attrs, _ = _transform_attrs(
-            C, {"x": attr.ib()}, False, False, False, True, None
+            C, {"x": attr.ib()}, False, KeywordOnly.NO, True, None
         )
 
         assert [] == base_attrs
@@ -540,10 +540,9 @@ class C:
                 repr=True,
                 eq=True,
                 order=True,
-                hash=_Hashability.HASHABLE,
+                hash=Hashability.HASHABLE,
                 match_args=False,
-                is_kw_only=True,
-                force_kw_only=True,
+                kw_only=KeywordOnly.FORCE,
                 has_weakref_slot=True,
                 collect_by_mro=False,
                 cache_hash=True,
@@ -574,10 +573,9 @@ class CDef:
                 repr=True,
                 eq=True,
                 order=True,
-                hash=_Hashability.UNHASHABLE,
+                hash=Hashability.UNHASHABLE,
                 match_args=True,
-                is_kw_only=False,
-                force_kw_only=True,
+                kw_only=KeywordOnly.NO,
                 has_weakref_slot=True,
                 collect_by_mro=False,
                 cache_hash=False,
@@ -2022,8 +2020,7 @@ class C:
                 order=False,
                 hash=False,
                 match_args=True,
-                is_kw_only=False,
-                force_kw_only=False,
+                kw_only=KeywordOnly.NO,
                 has_weakref_slot=False,
                 collect_by_mro=True,
                 cache_hash=False,
@@ -2059,8 +2056,7 @@ class C:
                 order=False,
                 hash=False,
                 match_args=True,
-                is_kw_only=False,
-                force_kw_only=False,
+                kw_only=KeywordOnly.NO,
                 has_weakref_slot=False,
                 collect_by_mro=True,
                 cache_hash=False,
@@ -2162,8 +2158,7 @@ def our_hasattr(obj, name, /) -> bool:
                 order=False,
                 hash=False,
                 match_args=True,
-                is_kw_only=False,
-                force_kw_only=False,
+                kw_only=KeywordOnly.NO,
                 has_weakref_slot=True,
                 collect_by_mro=True,
                 cache_hash=False,

tests/test_next_gen.py

@@ -15,7 +15,7 @@
 import attrs
 
 from attr._compat import PY_3_11_PLUS
-from attr._make import ClassProps, _Hashability
+from attr._make import ClassProps, Hashability, KeywordOnly
 
 
 @attrs.define
@@ -480,13 +480,12 @@ class C:
                 is_exception=False,
                 is_slotted=False,
                 is_frozen=True,
-                is_kw_only=True,
-                force_kw_only=False,
+                kw_only=KeywordOnly.YES,
                 init=True,
                 repr=True,
                 eq=True,
                 order=True,
-                hash=_Hashability.HASHABLE,
+                hash=Hashability.HASHABLE,
                 match_args=False,
                 has_weakref_slot=True,
                 collect_by_mro=True,
@@ -517,10 +516,9 @@ class C:
                 repr=True,
                 eq=True,
                 order=False,
-                hash=_Hashability.HASHABLE,  # b/c frozen
+                hash=Hashability.HASHABLE,  # b/c frozen
                 match_args=True,
-                is_kw_only=False,
-                force_kw_only=False,
+                kw_only=KeywordOnly.NO,
                 has_weakref_slot=True,
                 collect_by_mro=True,
                 cache_hash=False,