Make typemap_extensions the canonical import for users (#78)

The point here is to make sure that *clients* import the
`typemap.typing` stuff under a different name that `type_eval`
internals do, so that `typemap.type_eval` internals can still be
typechecked against the real `typemap.typing` while client code will
import `typemap_extensions` and will be able to see the proper
mypy/typeshed magic for it.

If we want to keep things under `typemap`, we could leave the public
version as `typemap.typing` and make the internal module
`typemap._typing_internals`. Thoughts?

Also do some fixups so that qblike_2 and fastapilike_2 basically pass
typechecking.

Author: msullivan

README.md

@@ -8,3 +8,12 @@ See [pep.rst](pep.rst) for the PEP draft and [design-qs.rst](design-qs.rst) for
 2. `$ cd typemap`
 3. `$ uv sync`
 4. `$ uv run pytest`
+
+## Running the typechecker
+
+If you have https://github.com/msullivan/mypy/tree/typemap active in a
+venv, you can run it against at least some of the tests with
+invocations like:
+  `mypy --python-version=3.14 tests/test_qblike_2.py`
+
+Not all of them run cleanly yet though.

pep.rst

@@ -1005,7 +1005,8 @@ as a literal type--all of these mechanisms lean very heavily on literal types.
                 for c in typing.Iter[typing.Attrs[K]]
             ]
         ]
-    ]: ...
+    ]:
+        raise NotImplementedError
 
 ConvertField is our first type helper, and it is a conditional type
 alias, which decides between two types based on a (limited)
@@ -1035,7 +1036,7 @@ grabs the argument to a ``Pointer``).
 
 ::
 
-    type PointerArg[T: Pointer] = typing.GetArg[T, Pointer, Literal[0]]
+    type PointerArg[T] = typing.GetArg[T, Pointer, Literal[0]]
 
 ``AdjustLink`` sticks a ``list`` around ``MultiLink``, using features
 we've discussed already.

pyproject.toml

@@ -6,6 +6,9 @@ readme = "README.md"
 requires-python = ">=3.14"
 dependencies = []
 
+[tool.setuptools.packages.find]
+include = ["typemap", "typemap_extensions"]
+
 [dependency-groups]
 test = [
     "pytest>=7.0",
@@ -68,7 +71,7 @@ extend-ignore = [
 [tool.ruff]
 line-length = 80
 indent-width = 4
-include = ["pyproject.toml", "typemap/**/*.py", "tests/**/*.py"]
+include = ["pyproject.toml", "typemap/**/*.py", "typemap_extensions/**/*.py", "tests/**/*.py"]
 
 [tool.ruff.format]
 quote-style = "preserve"

tests/format_helper.py

@@ -25,10 +25,10 @@ def format_meth(name, meth):
         code += f"    {attr_name}: {attr_type_s}{eq}\n"
 
     for name, attr in cls.__dict__.items():
-        if attr is typing._no_init_or_replace_init:
+        if attr is typing._no_init_or_replace_init:  # type: ignore[attr-defined]
             continue
         if isinstance(attr, classmethod):
-            attr = inspect.unwrap(attr)
+            attr = inspect.unwrap(attr)  # type: ignore[arg-type]
             code += f"    @classmethod\n"
         elif isinstance(attr, staticmethod):
             attr = inspect.unwrap(attr)

tests/test_astlike_1.py

@@ -2,7 +2,9 @@
 import typing
 
 from typemap.type_eval import eval_call_with_types, eval_typing, TypeMapError
-from typemap.typing import (
+from typemap.typing import _BoolLiteral
+
+from typemap_extensions import (
     Attrs,
     BaseTypedDict,
     Bool,
@@ -15,7 +17,6 @@
     Member,
     NewProtocol,
     RaiseError,
-    _BoolLiteral,
 )
 
 

tests/test_call.py

@@ -3,7 +3,7 @@
 from typing import Unpack
 
 from typemap.type_eval import eval_call
-from typemap.typing import (
+from typemap_extensions import (
     Attrs,
     BaseTypedDict,
     NewProtocol,

tests/test_eval_call_with_types.py

@@ -3,7 +3,7 @@
 from typing import Callable, Generic, Literal, Self, TypeVar
 
 from typemap.type_eval import eval_call_with_types
-from typemap.typing import (
+from typemap_extensions import (
     GenericCallable,
     GetArg,
     GetName,

tests/test_fastapilike_1.py

@@ -5,7 +5,7 @@
 from typing import Annotated, Callable, Literal, Union, Self
 
 from typemap.type_eval import eval_typing
-from typemap.typing import (
+from typemap_extensions import (
     NewProtocol,
     Iter,
     Attrs,

tests/test_fastapilike_2.py

@@ -6,9 +6,10 @@
     TypedDict,
     Never,
     Self,
+    TYPE_CHECKING,
 )
 
-from typemap import typing
+import typemap_extensions as typing
 
 
 class FieldArgs(TypedDict, total=False):
@@ -25,7 +26,7 @@ class Field[T: FieldArgs](typing.InitField[T]):
 ####
 
 # TODO: Should this go into the stdlib?
-type GetFieldItem[T: typing.InitField, K] = typing.GetMemberType[
+type GetFieldItem[T, K] = typing.GetMemberType[
     typing.GetArg[T, typing.InitField, Literal[0]], K
 ]
 
@@ -207,6 +208,11 @@ class Hero:
     secret_name: str = Field(hidden=True)
 
 
+# Quick reveal_type test for running mypy against this
+if TYPE_CHECKING:
+    pubhero: Public[Hero]
+    reveal_type(pubhero)  # noqa
+
 #######
 
 import textwrap

tests/test_nplike.py

@@ -1,6 +1,6 @@
 from typing import Literal
 
-from typemap import typing
+import typemap_extensions as typing
 
 import pytest