Optimize default plugin more

Author: JukkaL

mypy/plugins/constants.py

@@ -0,0 +1,18 @@
+"""Constant definitions for plugins kept here to help with import cycles."""
+
+from typing import Final
+
+from mypy.semanal_enum import ENUM_BASES
+
+SINGLEDISPATCH_TYPE: Final = "functools._SingleDispatchCallable"
+SINGLEDISPATCH_REGISTER_METHOD: Final = f"{SINGLEDISPATCH_TYPE}.register"
+SINGLEDISPATCH_CALLABLE_CALL_METHOD: Final = f"{SINGLEDISPATCH_TYPE}.__call__"
+SINGLEDISPATCH_REGISTER_RETURN_CLASS: Final = "_SingleDispatchRegisterCallable"
+SINGLEDISPATCH_REGISTER_CALLABLE_CALL_METHOD: Final = f"functools.{SINGLEDISPATCH_REGISTER_RETURN_CLASS}.__call__"
+
+ENUM_NAME_ACCESS: Final = {f"{prefix}.name" for prefix in ENUM_BASES} | {
+    f"{prefix}._name_" for prefix in ENUM_BASES
+}
+ENUM_VALUE_ACCESS: Final = {f"{prefix}.value" for prefix in ENUM_BASES} | {
+    f"{prefix}._value_" for prefix in ENUM_BASES
+}

mypy/plugins/default.py

@@ -15,7 +15,7 @@
     MethodSigContext,
     Plugin,
 )
-from mypy.plugins import singledispatch_const
+from mypy.plugins import constants
 from mypy.plugins.common import try_getting_str_literals
 from mypy.subtypes import is_subtype
 from mypy.typeops import is_literal_type_like, make_simplified_union
@@ -52,31 +52,39 @@ class DefaultPlugin(Plugin):
     """Type checker plugin that is enabled by default."""
 
     def get_function_hook(self, fullname: str) -> Callable[[FunctionContext], Type] | None:
-        from mypy.plugins import ctypes, enums, singledispatch
-
         if fullname == "_ctypes.Array":
+            from mypy.plugins import ctypes
+
             return ctypes.array_constructor_callback
         elif fullname == "functools.singledispatch":
+            from mypy.plugins import singledispatch
+
             return singledispatch.create_singledispatch_function_callback
         elif fullname == "functools.partial":
             import mypy.plugins.functools
 
             return mypy.plugins.functools.partial_new_callback
         elif fullname == "enum.member":
+            from mypy.plugins import enums
+
             return enums.enum_member_callback
 
         return None
 
     def get_function_signature_hook(
         self, fullname: str
     ) -> Callable[[FunctionSigContext], FunctionLike] | None:
-        from mypy.plugins import attrs, dataclasses
-
         if fullname in ("attr.evolve", "attrs.evolve", "attr.assoc", "attrs.assoc"):
+            from mypy.plugins import attrs
+
             return attrs.evolve_function_sig_callback
         elif fullname in ("attr.fields", "attrs.fields"):
+            from mypy.plugins import attrs
+
             return attrs.fields_function_sig_callback
         elif fullname == "dataclasses.replace":
+            from mypy.plugins import dataclasses
+
             return dataclasses.replace_function_sig_callback
         return None
 
@@ -93,7 +101,7 @@ def get_method_signature_hook(
             from mypy.plugins import ctypes
 
             return ctypes.array_setitem_callback
-        elif fullname == singledispatch_const.SINGLEDISPATCH_CALLABLE_CALL_METHOD:
+        elif fullname == constants.SINGLEDISPATCH_CALLABLE_CALL_METHOD:
             from mypy.plugins import singledispatch
 
             return singledispatch.call_singledispatch_function_callback
@@ -126,11 +134,11 @@ def get_method_hook(self, fullname: str) -> Callable[[MethodContext], Type] | No
             from mypy.plugins import ctypes
 
             return ctypes.array_iter_callback
-        elif fullname == singledispatch_const.SINGLEDISPATCH_REGISTER_METHOD:
+        elif fullname == constants.SINGLEDISPATCH_REGISTER_METHOD:
             from mypy.plugins import singledispatch
 
             return singledispatch.singledispatch_register_callback
-        elif fullname == singledispatch_const.REGISTER_CALLABLE_CALL_METHOD:
+        elif fullname == constants.SINGLEDISPATCH_REGISTER_CALLABLE_CALL_METHOD:
             from mypy.plugins import singledispatch
 
             return singledispatch.call_singledispatch_function_after_register_argument
@@ -141,15 +149,21 @@ def get_method_hook(self, fullname: str) -> Callable[[MethodContext], Type] | No
         return None
 
     def get_attribute_hook(self, fullname: str) -> Callable[[AttributeContext], Type] | None:
-        from mypy.plugins import ctypes, enums
-
         if fullname == "_ctypes.Array.value":
+            from mypy.plugins import ctypes
+
             return ctypes.array_value_callback
         elif fullname == "_ctypes.Array.raw":
+            from mypy.plugins import ctypes
+
             return ctypes.array_raw_callback
-        elif fullname in enums.ENUM_NAME_ACCESS:
+        elif fullname in constants.ENUM_NAME_ACCESS:
+            from mypy.plugins import enums
+
             return enums.enum_name_callback
-        elif fullname in enums.ENUM_VALUE_ACCESS:
+        elif fullname in constants.ENUM_VALUE_ACCESS:
+            from mypy.plugins import enums
+
             return enums.enum_value_callback
         return None
 

mypy/plugins/enums.py

@@ -18,7 +18,6 @@
 
 import mypy.plugin  # To avoid circular imports.
 from mypy.nodes import TypeInfo
-from mypy.semanal_enum import ENUM_BASES
 from mypy.subtypes import is_equivalent
 from mypy.typeops import fixup_partial_type, make_simplified_union
 from mypy.types import (
@@ -31,13 +30,6 @@
     is_named_instance,
 )
 
-ENUM_NAME_ACCESS: Final = {f"{prefix}.name" for prefix in ENUM_BASES} | {
-    f"{prefix}._name_" for prefix in ENUM_BASES
-}
-ENUM_VALUE_ACCESS: Final = {f"{prefix}.value" for prefix in ENUM_BASES} | {
-    f"{prefix}._value_" for prefix in ENUM_BASES
-}
-
 
 def enum_name_callback(ctx: mypy.plugin.AttributeContext) -> Type:
     """This plugin refines the 'name' attribute in enums to act as if

mypy/plugins/singledispatch.py

@@ -9,7 +9,7 @@
 from mypy.options import Options
 from mypy.plugin import CheckerPluginInterface, FunctionContext, MethodContext, MethodSigContext
 from mypy.plugins.common import add_method_to_class
-from mypy.plugins.singledispatch_const import REGISTER_RETURN_CLASS
+from mypy.plugins.constants import SINGLEDISPATCH_REGISTER_RETURN_CLASS
 from mypy.subtypes import is_subtype
 from mypy.types import (
     AnyType,
@@ -53,8 +53,8 @@ def get_first_arg(args: list[list[T]]) -> T | None:
 def make_fake_register_class_instance(
     api: CheckerPluginInterface, type_args: Sequence[Type]
 ) -> Instance:
-    defn = ClassDef(REGISTER_RETURN_CLASS, Block([]))
-    defn.fullname = f"functools.{REGISTER_RETURN_CLASS}"
+    defn = ClassDef(SINGLEDISPATCH_REGISTER_RETURN_CLASS, Block([]))
+    defn.fullname = f"functools.{SINGLEDISPATCH_REGISTER_RETURN_CLASS}"
     info = TypeInfo(SymbolTable(), defn, "functools")
     obj_type = api.named_generic_type("builtins.object", []).type
     info.bases = [Instance(obj_type, [])]