gh-149985: Remove future annotations and if TYPE_CHECKING in pyrepl

`from __future__ import annotations` is soft-deprecated now that evaluation
of annotations is always deferred. `if TYPE_CHECKING` can often be replaced
with lazy imports.

Author: JelleZijlstra

Lib/_pyrepl/_module_completer.py

@@ -1,5 +1,3 @@
-from __future__ import annotations
-
 import importlib
 import os
 import pkgutil
@@ -15,12 +13,9 @@
 from tokenize import TokenInfo
 from .fancycompleter import safe_getattr
 
-TYPE_CHECKING = False
-
-if TYPE_CHECKING:
-    from types import ModuleType
-    from typing import Any, Iterable, Iterator, Mapping
-    from .types import CompletionAction
+lazy from types import ModuleType
+lazy from typing import Any, Iterable, Iterator, Mapping
+lazy from .types import CompletionAction
 
 
 HARDCODED_SUBMODULES = {

Lib/_pyrepl/commands.py

@@ -19,10 +19,8 @@
 # CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 # CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-from __future__ import annotations
 import os
 import time
-from typing import TYPE_CHECKING
 
 # Categories of actions:
 #  killing
@@ -37,8 +35,7 @@
 from .trace import trace
 
 # types
-if TYPE_CHECKING:
-    from .historical_reader import HistoricalReader
+lazy from .historical_reader import HistoricalReader
 
 
 class Command:

Lib/_pyrepl/completing_reader.py

@@ -21,7 +21,6 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
-from typing import TYPE_CHECKING
 
 import re
 from . import commands, console, reader
@@ -30,9 +29,7 @@
 
 
 # types
-Command = commands.Command
-if TYPE_CHECKING:
-    from .types import CommandName, CompletionAction, Keymap, KeySpec
+lazy from .types import CompletionAction, Keymap
 
 
 def prefix(wordlist: list[str], j: int = 0) -> str:
@@ -285,7 +282,7 @@ def collect_keymap(self) -> Keymap:
         return super().collect_keymap() + (
             (r'\t', 'complete'),)
 
-    def after_command(self, cmd: Command) -> None:
+    def after_command(self, cmd: commands.Command) -> None:
         super().after_command(cmd)
         if not isinstance(cmd, (complete, self_insert)):
             self.cmpltn_reset()

Lib/_pyrepl/console.py

@@ -17,8 +17,6 @@
 # CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 # CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-from __future__ import annotations
-
 import os
 import _colorize
 
@@ -29,15 +27,13 @@
 from dataclasses import dataclass
 import re
 import sys
-from typing import TYPE_CHECKING
 
 from .render import RenderedScreen
 from .trace import trace
 
-if TYPE_CHECKING:
-    from typing import Callable, IO
-
-    from .types import CursorXY
+lazy from collections.abc import Callable
+lazy from typing import IO
+lazy from .types import CursorXY
 
 
 @dataclass

Lib/_pyrepl/content.py

@@ -1,5 +1,3 @@
-from __future__ import annotations
-
 from dataclasses import dataclass
 
 from .utils import ColorSpan, StyleRef, THEME, iter_display_chars, unbracket, wlen

Lib/_pyrepl/fancy_termios.py

@@ -19,13 +19,7 @@
 
 import termios
 
-
-TYPE_CHECKING = False
-
-if TYPE_CHECKING:
-    from typing import cast
-else:
-    cast = lambda typ, val: val
+from typing import cast
 
 
 class TermState:

Lib/_pyrepl/fancycompleter.py

@@ -3,21 +3,16 @@
 #
 #                        All Rights Reserved
 """Colorful tab completion for Python prompt"""
-from __future__ import annotations
-
 from _colorize import ANSIColors, get_colors, get_theme
 import rlcompleter
 import keyword
 import types
 
-TYPE_CHECKING = False
-
-if TYPE_CHECKING:
-    from typing import Any
-    from _colorize import Theme
+lazy from typing import Any
+lazy from _colorize import Theme
 
 
-def safe_getattr(obj, name):
+def safe_getattr(obj: object, name: str) -> object:
     # Mirror rlcompleter's safeguards so completion does not
     # call properties or reify lazy module attributes.
     if isinstance(getattr(type(obj), name, None), property):
@@ -35,7 +30,7 @@ def colorize_matches(names: list[str], values: list[Any], theme: Theme) -> list[
         for name, obj in zip(names, values)
     ]
 
-def _color_for_obj(name: str, value: Any, theme: Theme) -> str:
+def _color_for_obj(name: str, value: object, theme: Theme) -> str:
     t = type(value)
     color = _color_by_type(t, theme)
     return f"{color}{name}{ANSIColors.RESET}"

Lib/_pyrepl/historical_reader.py

@@ -17,17 +17,13 @@
 # CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 # CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-from __future__ import annotations
-
 from contextlib import contextmanager
 from dataclasses import dataclass, field
 
 from . import commands, input
 from .reader import Reader
 
-
-if False:
-    from .types import SimpleContextManager, KeySpec, CommandName
+lazy from .types import SimpleContextManager, KeySpec, CommandName
 
 
 isearch_keymap: tuple[tuple[KeySpec, CommandName], ...] = tuple(

Lib/_pyrepl/input.py

@@ -33,17 +33,12 @@
 # [meta-key] is identified with [esc key].  We demand that any console
 # class does quite a lot towards emulating a unix terminal.
 
-from __future__ import annotations
-
 from abc import ABC, abstractmethod
 import unicodedata
 from collections import deque
-from typing import TYPE_CHECKING
-
 
 # types
-if TYPE_CHECKING:
-    from .types import EventTuple
+lazy from .types import EventTuple
 
 
 class InputTranslator(ABC):

Lib/_pyrepl/layout.py

@@ -1,12 +1,11 @@
 """Wrap content lines to the terminal width before rendering."""
 
-from __future__ import annotations
-
 from dataclasses import dataclass
 from typing import Self
 
 from .content import ContentFragment, ContentLine
-from .types import CursorXY, ScreenInfoRow
+
+lazy from .types import CursorXY, ScreenInfoRow
 
 
 @dataclass(frozen=True, slots=True)