Add a typing compat module to avoid a dependency on typing-extensions for Py >= 3.8

sebastinas · sebastinas · commit 51ebc86070c7 · 2021-12-08T18:18:17.000+01:00
diff --git a/bpython/_typing_compat.py b/bpython/_typing_compat.py
@@ -0,0 +1,33 @@
+# The MIT License
+#
+# Copyright (c) 2021 Sebastian Ramacher
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+try:
+    # introduced in Python 3.8
+    from typing import Literal
+except ImportError:
+    from typing_extensions import Literal  # type: ignore
+
+try:
+    # introduced in Python 3.8
+    from typing import Protocol
+except ImportError:
+    from typing_extensions import Protocol  # type: ignore
diff --git a/bpython/curtsies.py b/bpython/curtsies.py
@@ -33,7 +33,7 @@
     Tuple,
     Union,
 )
-from typing_extensions import Protocol
+from ._typing_compat import Protocol
 
 logger = logging.getLogger(__name__)
 
diff --git a/bpython/curtsiesfrontend/_internal.py b/bpython/curtsiesfrontend/_internal.py
@@ -23,7 +23,7 @@
 import pydoc
 from types import TracebackType
 from typing import Optional, Type
-from typing_extensions import Literal
+from .._typing_compat import Literal
 
 from .. import _internal
 
diff --git a/bpython/curtsiesfrontend/repl.py b/bpython/curtsiesfrontend/repl.py
@@ -14,7 +14,7 @@
 from enum import Enum
 from types import TracebackType
 from typing import Dict, Any, List, Optional, Tuple, Union, cast, Type
-from typing_extensions import Literal
+from .._typing_compat import Literal
 
 import blessings
 import greenlet
diff --git a/bpython/filelock.py b/bpython/filelock.py
@@ -21,7 +21,7 @@
 # THE SOFTWARE.
 
 from typing import Optional, Type, IO
-from typing_extensions import Literal
+from ._typing_compat import Literal
 from types import TracebackType
 
 has_fcntl = True
diff --git a/bpython/inspection.py b/bpython/inspection.py
@@ -28,7 +28,7 @@
 from collections import namedtuple
 from typing import Any, Optional, Type
 from types import MemberDescriptorType, TracebackType
-from typing_extensions import Literal
+from ._typing_compat import Literal
 
 from pygments.token import Token
 from pygments.lexers import Python3Lexer
diff --git a/bpython/repl.py b/bpython/repl.py
@@ -38,7 +38,7 @@
 from pathlib import Path
 from types import ModuleType, TracebackType
 from typing import cast, Tuple, Any, Optional, Type
-from typing_extensions import Literal
+from ._typing_compat import Literal
 
 from pygments.lexers import Python3Lexer
 from pygments.token import Token
diff --git a/setup.cfg b/setup.cfg
@@ -27,7 +27,7 @@ install_requires =
     pygments
     pyxdg
     requests
-    typing-extensions
+    typing-extensions; python_version < "3.8"
 
 [options.extras_require]
 clipboard = pyperclip

Original file line number	Diff line number	Diff line change
`@@ -33,7 +33,7 @@`
`33`	`33`	`Tuple,`
`34`	`34`	`Union,`
`35`	`35`	`)`
`36`		`-from typing_extensions import Protocol`
	`36`	`+from ._typing_compat import Protocol`
`37`	`37`
`38`	`38`	`logger = logging.getLogger(__name__)`
`39`	`39`