Make typing_extensions a dev-dependency

Author: NeilGirdhar

jax/_src/api.py

@@ -28,11 +28,13 @@
 from functools import partial
 import inspect
 import math
-from typing import Any, Callable, Literal, NamedTuple, TypeVar, cast, overload
+from typing import (Any, Callable, Literal, NamedTuple, TypeVar, cast,
+                    overload, TYPE_CHECKING)
 import weakref
 
 import numpy as np
-from typing_extensions import ParamSpec
+if TYPE_CHECKING:
+  from typing_extensions import ParamSpec
 
 from jax._src import linear_util as lu
 from jax._src import stages
@@ -96,7 +98,10 @@
 T = TypeVar("T")
 U = TypeVar("U")
 V_co = TypeVar("V_co", covariant=True)
-P = ParamSpec("P")
+if TYPE_CHECKING:
+  P = ParamSpec("P")
+else:
+  P = TypeVar("P")
 
 
 map, unsafe_map = safe_map, map

jax/_src/pjit.py

@@ -589,6 +589,8 @@ def ax_leaf(l):
 V_co = TypeVar("V_co", covariant=True)
 if TYPE_CHECKING:
   P = ParamSpec("P")
+else:
+  P = TypeVar("P")
 
 
 class JitWrapped(stages.Wrapped[P, V_co], Generic[P, V_co]):

jax/_src/stages.py

@@ -32,10 +32,12 @@
 
 from collections.abc import Sequence
 from dataclasses import dataclass
-from typing import Any, Generic, NamedTuple, Protocol, TypeVar, Union
+from typing import (Any, Generic, NamedTuple, Protocol, TypeVar, Union,
+                    TYPE_CHECKING)
 import warnings
 
-from typing_extensions import ParamSpec
+if TYPE_CHECKING:
+  from typing_extensions import ParamSpec
 
 import jax
 
@@ -710,7 +712,10 @@ def cost_analysis(self) -> Any | None:
 
 
 V_co = TypeVar("V_co", covariant=True)
-P = ParamSpec("P")
+if TYPE_CHECKING:
+  P = ParamSpec("P")
+else:
+  P = TypeVar("P")
 
 
 class Wrapped(Protocol, Generic[P, V_co]):

setup.py

@@ -84,9 +84,9 @@ def generate_proto(source):
         # Python versions < 3.10. Can be dropped when 3.10 is the minimum
         # required Python version.
         'importlib_metadata>=4.6;python_version<"3.10"',
-        'typing_extensions>=4.5.0',
     ],
     extras_require={
+        'dev': ['typing_extensions>=4.8.0'],
         # Minimum jaxlib version; used in testing.
         'minimum-jaxlib': [f'jaxlib=={_minimum_jaxlib_version}'],