Merge pull request #167 from asottile/all-repos_autofix_systemexit-main

replace exit(main()) with raise SystemExit(main())

.github/FUNDING.yml

@@ -0,0 +1 @@
+github: asottile

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v2.5.0
+    rev: v4.0.1
     hooks:
     -   id: trailing-whitespace
     -   id: end-of-file-fixer
@@ -10,35 +10,35 @@ repos:
     -   id: double-quote-string-fixer
     -   id: name-tests-test
     -   id: requirements-txt-fixer
--   repo: https://gitlab.com/pycqa/flake8
-    rev: 3.7.9
+-   repo: https://github.com/PyCQA/flake8
+    rev: 4.0.1
     hooks:
     -   id: flake8
         additional_dependencies: [flake8-typing-imports==1.7.0]
 -   repo: https://github.com/pre-commit/mirrors-autopep8
-    rev: v1.5
+    rev: v1.5.7
     hooks:
     -   id: autopep8
 -   repo: https://github.com/asottile/reorder_python_imports
-    rev: v2.1.0
+    rev: v2.6.0
     hooks:
     -   id: reorder-python-imports
-        args: [--py3-plus]
+        args: [--py3-plus, --add-import, 'from __future__ import annotations']
 -   repo: https://github.com/asottile/add-trailing-comma
-    rev: v2.0.1
+    rev: v2.1.0
     hooks:
     -   id: add-trailing-comma
         args: [--py36-plus]
 -   repo: https://github.com/asottile/pyupgrade
-    rev: v2.1.0
+    rev: v2.29.0
     hooks:
     -   id: pyupgrade
-        args: [--py36-plus]
+        args: [--py37-plus]
 -   repo: https://github.com/asottile/setup-cfg-fmt
-    rev: v1.7.0
+    rev: v1.18.0
     hooks:
     -   id: setup-cfg-fmt
 -   repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v0.770
+    rev: v0.910-1
     hooks:
     -   id: mypy

README.md

@@ -1,5 +1,8 @@
 [![Build Status](https://dev.azure.com/asottile/asottile/_apis/build/status/asottile.babi?branchName=master)](https://dev.azure.com/asottile/asottile/_build/latest?definitionId=29&branchName=master)
 [![Azure DevOps coverage](https://img.shields.io/azure-devops/coverage/asottile/asottile/29/master.svg)](https://dev.azure.com/asottile/asottile/_build/latest?definitionId=29&branchName=master)
+[![pre-commit.ci status](https://results.pre-commit.ci/badge/github/asottile/babi/master.svg)](https://results.pre-commit.ci/latest/github/asottile/babi/master)
+
+![babi logo](https://user-images.githubusercontent.com/1810591/89981369-9ed84e80-dc28-11ea-9708-5f4c49c09632.png)
 
 babi
 ====
@@ -12,9 +15,16 @@ a text editor, eventually...
 
 ### why is it called babi?
 
-I usually use the text editor `nano`, frequently I typo this.  on a qwerty
+I used to use the text editor `nano`, frequently I typo this.  on a qwerty
 keyboard, when the right hand is shifted left by one, `nano` becomes `babi`.
 
+### babi vs. nano
+
+here is a youtube video where I discuss the motivation for creating and using
+`babi` instead of `nano`:
+
+[![youtube video about babi](https://img.youtube.com/vi/WyR1hAGmR3g/mqdefault.jpg)](https://youtu.be/WyR1hAGmR3g)
+
 ### quitting babi
 
 currently you can quit `babi` by using <kbd>^X</kbd> (or via <kbd>esc</kbd> +
@@ -45,7 +55,7 @@ these are all of the current key bindings in babi
 - <kbd>tab</kbd> / <kbd>shift-tab</kbd>: indent or dedent current line (or
   selection)
 - <kbd>^K</kbd> / <kbd>^U</kbd>: cut and uncut the current line (or selection)
-- <kbd>M-u</kbd> / <kbd>M-U</kbd>: undo / redo
+- <kbd>M-u</kbd> / <kbd>M-U</kbd> or <kbd>M-e</kbd>: undo / redo
 - <kbd>^W</kbd>: search
 - <kbd>^\\</kbd>: search and replace
 - <kbd>^C</kbd>: show the current position in the file
@@ -77,6 +87,25 @@ here's a modified vs dark plus theme that works:
 ./bin/download-theme vs-dark-asottile https://gist.github.com/asottile/b465856c82b1aaa4ba8c7c6314a72e13/raw/22d602fb355fb12b04f176a733941ba5713bc36c/vs_dark_asottile.json
 ```
 
+### keyboard shortcuts on macos
+
+to get the most out of babi's built in keyboard shortcuts, a few settings must
+be changed on macos with Terminal.app:
+
+- in **System Preferences**: **Keyboard** > **Shortcuts** >
+  **Mission Control**: disable or rebind "Move left a space" and
+  "Move right a space" (the defaults `⌃ →` and `⌃ ←` conflict)
+- in **Terminal.app**: **Terminal** > **Preferences** > **Profiles** >
+  **Keyboard**:
+    - check **Use Option as Meta key**
+    - ensure the following keys are enabled:
+        - `⌃ →`: `\033[1;5C`
+        - `⌃ ←`: `\033[1;5D`
+        - `⇧ ↑`: `\033[1;2A`
+        - `⇧ ↓`: `\033[1;2B`
+        - `⇧ →`: `\033[1;2C`
+        - `⇧ ←`: `\033[1;2D`
+
 ## demos
 
 most things work!  here's a few screenshots
@@ -87,7 +116,7 @@ this opens the file, displays it, and can be edited and can save! unknown keys
 are displayed as errors in the status bar.  babi will scroll if the cursor
 goes off screen either from resize events or from movement.  babi can edit
 multiple files.  babi has a command mode (so you can quit it like vim
-<kbd>:q</kbd>!).  babi also support syntax highlighting
+<kbd>:q</kbd>!).  babi also supports syntax highlighting
 
 ![](https://i.fluffy.cc/5WFZBJ4mWs7wtThD9strQnGlJqw4Z9KS.png)
 

azure-pipelines.yml

@@ -10,11 +10,10 @@ resources:
       type: github
       endpoint: github
       name: asottile/azure-pipeline-templates
-      ref: refs/tags/v1.0.0
+      ref: refs/tags/v2.1.0
 
 jobs:
-- template: job--pre-commit.yml@asottile
 - template: job--python-tox.yml@asottile
   parameters:
-    toxenvs: [py36, py37, py38]
+    toxenvs: [py37, py38, py39]
     os: linux

babi/__main__.py

@@ -1,4 +1,6 @@
+from __future__ import annotations
+
 from babi.main import main
 
 if __name__ == '__main__':
-    exit(main())
+    raise SystemExit(main())

babi/_types.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:

babi/buf.py

@@ -1,12 +1,11 @@
+from __future__ import annotations
+
 import bisect
 import contextlib
 from typing import Callable
 from typing import Generator
 from typing import Iterator
-from typing import List
 from typing import NamedTuple
-from typing import Optional
-from typing import Tuple
 
 from babi._types import Protocol
 from babi.horizontal_scrolling import line_x
@@ -19,25 +18,25 @@ DelCallback = Callable[['Buf', int, str], None]
 InsCallback = Callable[['Buf', int], None]
 
 
-def _offsets(s: str) -> Tuple[int, ...]:
+def _offsets(s: str, tab_size: int) -> tuple[int, ...]:
     ret = [0]
     for c in s:
         if c == '\t':
-            ret.append(ret[-1] + (4 - ret[-1] % 4))
+            ret.append(ret[-1] + (tab_size - ret[-1] % tab_size))
         else:
             ret.append(ret[-1] + wcwidth(c))
     return tuple(ret)
 
 
 class Modification(Protocol):
-    def __call__(self, buf: 'Buf') -> None: ...
+    def __call__(self, buf: Buf) -> None: ...
 
 
 class SetModification(NamedTuple):
     idx: int
     s: str
 
-    def __call__(self, buf: 'Buf') -> None:
+    def __call__(self, buf: Buf) -> None:
         buf[self.idx] = self.s
 
 
@@ -45,27 +44,29 @@ class InsModification(NamedTuple):
     idx: int
     s: str
 
-    def __call__(self, buf: 'Buf') -> None:
+    def __call__(self, buf: Buf) -> None:
         buf.insert(self.idx, self.s)
 
 
 class DelModification(NamedTuple):
     idx: int
 
-    def __call__(self, buf: 'Buf') -> None:
+    def __call__(self, buf: Buf) -> None:
         del buf[self.idx]
 
 
 class Buf:
-    def __init__(self, lines: List[str]) -> None:
+    def __init__(self, lines: list[str], tab_size: int = 4) -> None:
         self._lines = lines
+        self.expandtabs = True
+        self.tab_size = tab_size
         self.file_y = self.y = self._x = self._x_hint = 0
 
-        self._set_callbacks: List[SetCallback] = [self._set_cb]
-        self._del_callbacks: List[DelCallback] = [self._del_cb]
-        self._ins_callbacks: List[InsCallback] = [self._ins_cb]
+        self._set_callbacks: list[SetCallback] = [self._set_cb]
+        self._del_callbacks: list[DelCallback] = [self._del_cb]
+        self._ins_callbacks: list[InsCallback] = [self._ins_cb]
 
-        self._positions: List[Optional[Tuple[int, ...]]] = []
+        self._positions: list[tuple[int, ...] | None] = []
 
     # read only interface
 
@@ -136,6 +137,10 @@ class Buf:
         if self[-1] != '':
             self.append('')
 
+    def set_tab_size(self, tab_size: int) -> None:
+        self.tab_size = tab_size
+        self._positions = [None]
+
     # event handling
 
     def add_set_callback(self, cb: SetCallback) -> None:
@@ -157,16 +162,16 @@ class Buf:
         self._ins_callbacks.remove(cb)
 
     @contextlib.contextmanager
-    def record(self) -> Generator[List[Modification], None, None]:
-        modifications: List[Modification] = []
+    def record(self) -> Generator[list[Modification], None, None]:
+        modifications: list[Modification] = []
 
-        def set_cb(buf: 'Buf', idx: int, victim: str) -> None:
+        def set_cb(buf: Buf, idx: int, victim: str) -> None:
             modifications.append(SetModification(idx, victim))
 
-        def del_cb(buf: 'Buf', idx: int, victim: str) -> None:
+        def del_cb(buf: Buf, idx: int, victim: str) -> None:
             modifications.append(InsModification(idx, victim))
 
-        def ins_cb(buf: 'Buf', idx: int) -> None:
+        def ins_cb(buf: Buf, idx: int) -> None:
             modifications.append(DelModification(idx))
 
         self.add_set_callback(set_cb)
@@ -179,7 +184,7 @@ class Buf:
             self.remove_del_callback(del_cb)
             self.remove_set_callback(set_cb)
 
-    def apply(self, modifications: List[Modification]) -> List[Modification]:
+    def apply(self, modifications: list[Modification]) -> list[Modification]:
         with self.record() as ret_modifications:
             for modification in reversed(modifications):
                 modification(self)
@@ -203,23 +208,24 @@ class Buf:
     def _extend_positions(self, idx: int) -> None:
         self._positions.extend([None] * (1 + idx - len(self._positions)))
 
-    def _set_cb(self, buf: 'Buf', idx: int, victim: str) -> None:
+    def _set_cb(self, buf: Buf, idx: int, victim: str) -> None:
         self._extend_positions(idx)
         self._positions[idx] = None
 
-    def _del_cb(self, buf: 'Buf', idx: int, victim: str) -> None:
+    def _del_cb(self, buf: Buf, idx: int, victim: str) -> None:
         self._extend_positions(idx)
         del self._positions[idx]
 
-    def _ins_cb(self, buf: 'Buf', idx: int) -> None:
+    def _ins_cb(self, buf: Buf, idx: int) -> None:
         self._extend_positions(idx)
         self._positions.insert(idx, None)
 
-    def line_positions(self, idx: int) -> Tuple[int, ...]:
+    def line_positions(self, idx: int) -> tuple[int, ...]:
         self._extend_positions(idx)
         value = self._positions[idx]
         if value is None:
-            value = self._positions[idx] = _offsets(self._lines[idx])
+            value = _offsets(self._lines[idx], self.tab_size)
+            self._positions[idx] = value
         return value
 
     def line_x(self, margin: Margin) -> int:
@@ -229,16 +235,24 @@ class Buf:
     def _cursor_x(self) -> int:
         return self.line_positions(self.y)[self.x]
 
-    def cursor_position(self, margin: Margin) -> Tuple[int, int]:
+    def cursor_position(self, margin: Margin) -> tuple[int, int]:
         y = self.y - self.file_y + margin.header
         x = self._cursor_x - self.line_x(margin)
         return y, x
 
     # rendered lines
 
+    @property
+    def tab_string(self) -> str:
+        if self.expandtabs:
+            return ' ' * self.tab_size
+        else:
+            return '\t'
+
     def rendered_line(self, idx: int, margin: Margin) -> str:
         x = self._cursor_x if idx == self.y else 0
-        return scrolled_line(self._lines[idx].expandtabs(4), x, margin.cols)
+        expanded = self._lines[idx].expandtabs(self.tab_size)
+        return scrolled_line(expanded, x, margin.cols)
 
     # movement
 

babi/cached_property.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import sys
 
 if sys.version_info >= (3, 8):  # pragma: no cover (>=py38)
@@ -5,8 +7,6 @@ if sys.version_info >= (3, 8):  # pragma: no cover (>=py38)
 else:  # pragma: no cover (<py38)
     from typing import Callable
     from typing import Generic
-    from typing import Optional
-    from typing import Type
     from typing import TypeVar
 
     TSelf = TypeVar('TSelf')
@@ -18,8 +18,8 @@ else:  # pragma: no cover (<py38)
 
         def __get__(
                 self,
-                instance: Optional[TSelf],
-                owner: Optional[Type[TSelf]] = None,
+                instance: TSelf | None,
+                owner: type[TSelf] | None = None,
         ) -> TRet:
             assert instance is not None
             ret = instance.__dict__[self._func.__name__] = self._func(instance)

babi/color.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from typing import NamedTuple
 
 # TODO: find a standard which defines these
@@ -11,7 +13,7 @@ class Color(NamedTuple):
     b: int
 
     @classmethod
-    def parse(cls, s: str) -> 'Color':
+    def parse(cls, s: str) -> Color:
         if s.startswith('#') and len(s) >= 7:
             return cls(r=int(s[1:3], 16), g=int(s[3:5], 16), b=int(s[5:7], 16))
         elif s.startswith('#'):

babi/color_kd.py

@@ -1,9 +1,8 @@
+from __future__ import annotations
+
 import functools
 import itertools
-from typing import List
 from typing import NamedTuple
-from typing import Optional
-from typing import Tuple
 
 from babi._types import Protocol
 from babi.color import Color
@@ -19,19 +18,19 @@ class KD(Protocol):
     @property
     def n(self) -> int: ...
     @property
-    def left(self) -> Optional['KD']: ...
+    def left(self) -> KD | None: ...
     @property
-    def right(self) -> Optional['KD']: ...
+    def right(self) -> KD | None: ...
 
 
 class _KD(NamedTuple):
     color: Color
     n: int
-    left: Optional[KD]
-    right: Optional[KD]
+    left: KD | None
+    right: KD | None
 
 
-def _build(colors: List[Tuple[Color, int]], depth: int = 0) -> Optional[KD]:
+def _build(colors: list[tuple[Color, int]], depth: int = 0) -> KD | None:
     if not colors:
         return None
 
@@ -46,11 +45,11 @@ def _build(colors: List[Tuple[Color, int]], depth: int = 0) -> Optional[KD]:
     )
 
 
-def nearest(color: Color, colors: Optional[KD]) -> int:
+def nearest(color: Color, colors: KD | None) -> int:
     best = 0
     dist = 2 ** 32
 
-    def _search(kd: Optional[KD], *, depth: int) -> None:
+    def _search(kd: KD | None, *, depth: int) -> None:
         nonlocal best
         nonlocal dist
 
@@ -77,7 +76,7 @@ def nearest(color: Color, colors: Optional[KD]) -> int:
 
 
 @functools.lru_cache(maxsize=1)
-def make_256() -> Optional[KD]:
+def make_256() -> KD | None:
     vals = (0, 95, 135, 175, 215, 255)
     colors = [
         (Color(r, g, b), i)

babi/color_manager.py

@@ -1,21 +1,20 @@
+from __future__ import annotations
+
 import curses
-from typing import Dict
 from typing import NamedTuple
-from typing import Optional
-from typing import Tuple
 
 from babi import color_kd
 from babi.color import Color
 
 
-def _color_to_curses(color: Color) -> Tuple[int, int, int]:
+def _color_to_curses(color: Color) -> tuple[int, int, int]:
     factor = 1000 / 255
     return int(color.r * factor), int(color.g * factor), int(color.b * factor)
 
 
 class ColorManager(NamedTuple):
-    colors: Dict[Color, int]
-    raw_pairs: Dict[Tuple[int, int], int]
+    colors: dict[Color, int]
+    raw_pairs: dict[tuple[int, int], int]
 
     def init_color(self, color: Color) -> None:
         if curses.can_change_color():
@@ -27,21 +26,24 @@ class ColorManager(NamedTuple):
         else:
             self.colors[color] = -1
 
-    def color_pair(self, fg: Optional[Color], bg: Optional[Color]) -> int:
+    def color_pair(self, fg: Color | None, bg: Color | None) -> int:
         fg_i = self.colors[fg] if fg is not None else -1
         bg_i = self.colors[bg] if bg is not None else -1
         return self.raw_color_pair(fg_i, bg_i)
 
     def raw_color_pair(self, fg: int, bg: int) -> int:
-        try:
-            return self.raw_pairs[(fg, bg)]
-        except KeyError:
-            pass
+        if curses.COLORS > 0:
+            try:
+                return self.raw_pairs[(fg, bg)]
+            except KeyError:
+                pass
 
-        n = self.raw_pairs[(fg, bg)] = len(self.raw_pairs) + 1
-        curses.init_pair(n, fg, bg)
-        return n
+            n = self.raw_pairs[(fg, bg)] = len(self.raw_pairs) + 1
+            curses.init_pair(n, fg, bg)
+            return n
+        else:
+            return 0
 
     @classmethod
-    def make(cls) -> 'ColorManager':
+    def make(cls) -> ColorManager:
         return cls({}, {})

babi/fdict.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from typing import Generic
 from typing import Iterable
 from typing import Mapping

babi/file.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import collections
 import contextlib
 import curses
@@ -6,20 +8,17 @@ import hashlib
 import io
 import itertools
 import os.path
+import re
 from typing import Any
 from typing import Callable
 from typing import cast
 from typing import Generator
 from typing import IO
-from typing import List
 from typing import Match
 from typing import NamedTuple
-from typing import Optional
 from typing import Pattern
-from typing import Tuple
 from typing import TYPE_CHECKING
 from typing import TypeVar
-from typing import Union
 
 from babi.buf import Buf
 from babi.buf import Modification
@@ -38,8 +37,10 @@ if TYPE_CHECKING:
 
 TCallable = TypeVar('TCallable', bound=Callable[..., Any])
 
+WS_RE = re.compile(r'^\s*')
 
-def get_lines(sio: IO[str]) -> Tuple[List[str], str, bool, str]:
+
+def get_lines(sio: IO[str]) -> tuple[list[str], str, bool, str]:
     sha256 = hashlib.sha256()
     lines = []
     newlines = collections.Counter({'\n': 0})  # default to `\n`
@@ -61,7 +62,7 @@ def get_lines(sio: IO[str]) -> Tuple[List[str], str, bool, str]:
 
 class Action:
     def __init__(
-            self, *, name: str, modifications: List[Modification],
+            self, *, name: str, modifications: list[Modification],
             start_x: int, start_y: int, start_modified: bool,
             end_x: int, end_y: int, end_modified: bool,
             final: bool,
@@ -76,7 +77,7 @@ class Action:
         self.end_modified = end_modified
         self.final = final
 
-    def apply(self, file: 'File') -> 'Action':
+    def apply(self, file: File) -> Action:
         action = Action(
             name=self.name, modifications=file.buf.apply(self.modifications),
             start_x=self.end_x, start_y=self.end_y,
@@ -95,7 +96,7 @@ class Action:
 
 def action(func: TCallable) -> TCallable:
     @functools.wraps(func)
-    def action_inner(self: 'File', *args: Any, **kwargs: Any) -> Any:
+    def action_inner(self: File, *args: Any, **kwargs: Any) -> Any:
         self.finalize_previous_action()
         return func(self, *args, **kwargs)
     return cast(TCallable, action_inner)
@@ -108,7 +109,7 @@ def edit_action(
 ) -> Callable[[TCallable], TCallable]:
     def edit_action_decorator(func: TCallable) -> TCallable:
         @functools.wraps(func)
-        def edit_action_inner(self: 'File', *args: Any, **kwargs: Any) -> Any:
+        def edit_action_inner(self: File, *args: Any, **kwargs: Any) -> Any:
             with self.edit_action_context(name, final=final):
                 return func(self, *args, **kwargs)
         return cast(TCallable, edit_action_inner)
@@ -117,7 +118,7 @@ def edit_action(
 
 def keep_selection(func: TCallable) -> TCallable:
     @functools.wraps(func)
-    def keep_selection_inner(self: 'File', *args: Any, **kwargs: Any) -> Any:
+    def keep_selection_inner(self: File, *args: Any, **kwargs: Any) -> Any:
         with self.select():
             return func(self, *args, **kwargs)
     return cast(TCallable, keep_selection_inner)
@@ -125,7 +126,7 @@ def keep_selection(func: TCallable) -> TCallable:
 
 def clear_selection(func: TCallable) -> TCallable:
     @functools.wraps(func)
-    def clear_selection_inner(self: 'File', *args: Any, **kwargs: Any) -> Any:
+    def clear_selection_inner(self: File, *args: Any, **kwargs: Any) -> Any:
         ret = func(self, *args, **kwargs)
         self.selection.clear()
         return ret
@@ -140,7 +141,7 @@ class Found(NamedTuple):
 class _SearchIter:
     def __init__(
             self,
-            file: 'File',
+            file: File,
             reg: Pattern[str],
             *,
             offset: int,
@@ -152,7 +153,7 @@ class _SearchIter:
         self._start_x = file.buf.x + offset
         self._start_y = file.buf.y
 
-    def __iter__(self) -> '_SearchIter':
+    def __iter__(self) -> _SearchIter:
         return self
 
     def _stop_if_past_original(self, y: int, match: Match[str]) -> Found:
@@ -165,7 +166,7 @@ class _SearchIter:
             raise StopIteration()
         return Found(y, match)
 
-    def __next__(self) -> Tuple[int, Match[str]]:
+    def __next__(self) -> tuple[int, Match[str]]:
         x = self.file.buf.x + self.offset
         y = self.file.buf.y
 
@@ -197,25 +198,32 @@ class _SearchIter:
 class File:
     def __init__(
             self,
-            filename: Optional[str],
+            filename: str | None,
+            initial_line: int,
             color_manager: ColorManager,
-            hl_factories: Tuple[HLFactory, ...],
+            hl_factories: tuple[HLFactory, ...],
     ) -> None:
         self.filename = filename
+        self.initial_line = initial_line
         self.modified = False
         self.buf = Buf([])
         self.nl = '\n'
-        self.sha256: Optional[str] = None
+        self.sha256: str | None = None
         self._in_edit_action = False
-        self.undo_stack: List[Action] = []
-        self.redo_stack: List[Action] = []
+        self.undo_stack: list[Action] = []
+        self.redo_stack: list[Action] = []
         self._hl_factories = hl_factories
         self._trailing_whitespace = TrailingWhitespace(color_manager)
         self._replace_hl = Replace()
         self.selection = Selection()
-        self._file_hls: Tuple[FileHL, ...] = ()
+        self._file_hls: tuple[FileHL, ...] = ()
 
-    def ensure_loaded(self, status: Status, stdin: str) -> None:
+    def ensure_loaded(
+            self,
+            status: Status,
+            margin: Margin,
+            stdin: str,
+    ) -> None:
         if self.buf:
             return
 
@@ -226,7 +234,7 @@ class File:
             sio = io.StringIO(stdin)
             lines, self.nl, mixed, self.sha256 = get_lines(sio)
         elif self.filename is not None and os.path.isfile(self.filename):
-            with open(self.filename, newline='') as f:
+            with open(self.filename, encoding='UTF-8', newline='') as f:
                 lines, self.nl, mixed, self.sha256 = get_lines(f)
         else:
             if self.filename is not None:
@@ -237,7 +245,7 @@ class File:
                     status.update('(new file)')
             lines, self.nl, mixed, self.sha256 = get_lines(io.StringIO(''))
 
-        self.buf = Buf(lines)
+        self.buf = Buf(lines, self.buf.tab_size)
 
         if mixed:
             status.update(f'mixed newlines will be converted to {self.nl!r}')
@@ -257,6 +265,8 @@ class File:
         for file_hl in self._file_hls:
             file_hl.register_callbacks(self.buf)
 
+        self.go_to_line(self.initial_line, margin)
+
     def __repr__(self) -> str:
         return f'<{type(self).__name__} {self.filename!r}>'
 
@@ -383,14 +393,14 @@ class File:
     @clear_selection
     def replace(
             self,
-            screen: 'Screen',
+            screen: Screen,
             reg: Pattern[str],
             replace: str,
     ) -> None:
         self.finalize_previous_action()
 
         count = 0
-        res: Union[str, PromptResult] = ''
+        res: str | PromptResult = ''
         search = _SearchIter(self, reg, offset=0)
         for line_y, match in search:
             end = match.end()
@@ -464,7 +474,11 @@ class File:
         if self.buf.y == 0 and self.buf.x == 0:
             pass
         # backspace at the end of the file does not change the contents
-        elif self.buf.y == len(self.buf) - 1:
+        elif (
+                self.buf.y == len(self.buf) - 1 and
+                # still allow backspace if there are 2+ blank lines
+                self.buf[self.buf.y - 1] != ''
+        ):
             self.buf.left(margin)
         # at the beginning of the line, we join the current line and
         # the previous line
@@ -512,20 +526,29 @@ class File:
         assert self.selection.start is not None
         sel_y, sel_x = self.selection.start
         (s_y, _), (e_y, _) = self.selection.get()
+        tab_string = self.buf.tab_string
+        tab_size = len(tab_string)
         for l_y in range(s_y, e_y + 1):
             if self.buf[l_y]:
-                self.buf[l_y] = ' ' * 4 + self.buf[l_y]
+                self.buf[l_y] = tab_string + self.buf[l_y]
                 if l_y == self.buf.y:
-                    self.buf.x += 4
+                    self.buf.x += tab_size
                 if l_y == sel_y and sel_x != 0:
-                    sel_x += 4
+                    sel_x += tab_size
         self.selection.set(sel_y, sel_x, self.buf.y, self.buf.x)
 
     @edit_action('insert tab', final=False)
     def _tab(self, margin: Margin) -> None:
-        n = 4 - self.buf.x % 4
+        tab_string = self.buf.tab_string
+        if tab_string == '\t':
+            n = 1
+        else:
+            n = self.buf.tab_size - self.buf.x % self.buf.tab_size
+            tab_string = tab_string[:n]
         line = self.buf[self.buf.y]
-        self.buf[self.buf.y] = line[:self.buf.x] + n * ' ' + line[self.buf.x:]
+        self.buf[self.buf.y] = (
+            line[:self.buf.x] + tab_string + line[self.buf.x:]
+        )
         self.buf.x += n
         self.buf.restore_eof_invariant()
 
@@ -535,11 +558,10 @@ class File:
         else:
             self._tab(margin)
 
-    @staticmethod
-    def _dedent_line(s: str) -> int:
-        bound = min(len(s), 4)
+    def _dedent_line(self, s: str) -> int:
+        bound = min(len(s), len(self.buf.tab_string))
         i = 0
-        while i < bound and s[i] == ' ':
+        while i < bound and s[i] in (' ', '\t'):
             i += 1
         return i
 
@@ -573,7 +595,7 @@ class File:
 
     @edit_action('cut selection', final=True)
     @clear_selection
-    def cut_selection(self, margin: Margin) -> Tuple[str, ...]:
+    def cut_selection(self, margin: Margin) -> tuple[str, ...]:
         ret = []
         (s_y, s_x), (e_y, e_x) = self.selection.get()
         if s_y == e_y:
@@ -593,7 +615,7 @@ class File:
         self.buf.scroll_screen_if_needed(margin)
         return tuple(ret)
 
-    def cut(self, cut_buffer: Tuple[str, ...]) -> Tuple[str, ...]:
+    def cut(self, cut_buffer: tuple[str, ...]) -> tuple[str, ...]:
         # only continue a cut if the last action is a non-final cut
         if not self._continue_last_action('cut'):
             cut_buffer = ()
@@ -606,7 +628,7 @@ class File:
                 self.buf.x = 0
                 return cut_buffer + (victim,)
 
-    def _uncut(self, cut_buffer: Tuple[str, ...], margin: Margin) -> None:
+    def _uncut(self, cut_buffer: tuple[str, ...], margin: Margin) -> None:
         for cut_line in cut_buffer:
             line = self.buf[self.buf.y]
             before, after = line[:self.buf.x], line[self.buf.x:]
@@ -617,14 +639,14 @@ class File:
 
     @edit_action('uncut', final=True)
     @clear_selection
-    def uncut(self, cut_buffer: Tuple[str, ...], margin: Margin) -> None:
+    def uncut(self, cut_buffer: tuple[str, ...], margin: Margin) -> None:
         self._uncut(cut_buffer, margin)
 
     @edit_action('uncut selection', final=True)
     @clear_selection
     def uncut_selection(
             self,
-            cut_buffer: Tuple[str, ...], margin: Margin,
+            cut_buffer: tuple[str, ...], margin: Margin,
     ) -> None:
         self._uncut(cut_buffer, margin)
         self.buf.up(margin)
@@ -632,9 +654,9 @@ class File:
         self.buf[self.buf.y] += self.buf.pop(self.buf.y + 1)
         self.buf.restore_eof_invariant()
 
-    def _sort(self, margin: Margin, s_y: int, e_y: int) -> None:
+    def _sort(self, margin: Margin, s_y: int, e_y: int, reverse: bool) -> None:
         # self.buf intentionally does not support slicing so we use islice
-        lines = sorted(itertools.islice(self.buf, s_y, e_y))
+        lines = sorted(itertools.islice(self.buf, s_y, e_y), reverse=reverse)
         for i, line in zip(range(s_y, e_y), lines):
             self.buf[i] = line
 
@@ -642,18 +664,78 @@ class File:
         self.buf.x = 0
         self.buf.scroll_screen_if_needed(margin)
 
-    @edit_action('sort', final=True)
-    def sort(self, margin: Margin) -> None:
-        self._sort(margin, 0, len(self.buf) - 1)
-
-    @edit_action('sort selection', final=True)
-    @clear_selection
-    def sort_selection(self, margin: Margin) -> None:
+    def _selection_lines(self) -> tuple[int, int]:
         (s_y, _), (e_y, _) = self.selection.get()
         e_y = min(e_y + 1, len(self.buf) - 1)
         if self.buf[e_y - 1] == '':
             e_y -= 1
-        self._sort(margin, s_y, e_y)
+        return s_y, e_y
+
+    @edit_action('sort', final=True)
+    def sort(self, margin: Margin, reverse: bool = False) -> None:
+        self._sort(margin, 0, len(self.buf) - 1, reverse=reverse)
+
+    @edit_action('sort selection', final=True)
+    @clear_selection
+    def sort_selection(self, margin: Margin, reverse: bool = False) -> None:
+        s_y, e_y = self._selection_lines()
+        self._sort(margin, s_y, e_y, reverse=reverse)
+
+    def _is_commented(self, lineno: int, prefix: str) -> bool:
+        return self.buf[lineno].lstrip().startswith(prefix)
+
+    def _indent(self, lineno: int) -> str:
+        ws_match = WS_RE.match(self.buf[lineno])
+        assert ws_match is not None
+        return ws_match[0]
+
+    def _minimum_indent_for_selection(self) -> int:
+        s_y, e_y = self._selection_lines()
+        return min(len(self._indent(lineno)) for lineno in range(s_y, e_y))
+
+    def _comment_remove(self, lineno: int, prefix: str) -> None:
+        line = self.buf[lineno]
+        indent = self._indent(lineno)
+        ws_len = len(indent)
+
+        if line.startswith(f'{prefix} ', ws_len):
+            self.buf[lineno] = f'{indent}{line[ws_len + len(prefix) + 1:]}'
+        elif line.startswith(prefix, ws_len):
+            self.buf[lineno] = f'{indent}{line[ws_len + len(prefix):]}'
+
+        if self.buf.y == lineno and self.buf.x > ws_len:
+            self.buf.x -= len(line) - len(self.buf[lineno])
+
+    def _comment_add(self, lineno: int, prefix: str, s_offset: int) -> None:
+        line = self.buf[lineno]
+
+        if not line:
+            self.buf[lineno] = f'{prefix}'
+        else:
+            self.buf[lineno] = f'{line[:s_offset]}{prefix} {line[s_offset:]}'
+
+        if lineno == self.buf.y and self.buf.x > s_offset:
+            self.buf.x += len(self.buf[lineno]) - len(line)
+
+    @edit_action('comment', final=True)
+    def toggle_comment(self, prefix: str) -> None:
+        if self._is_commented(self.buf.y, prefix):
+            self._comment_remove(self.buf.y, prefix)
+        else:
+            ws_len = len(self._indent(self.buf.y))
+            self._comment_add(self.buf.y, prefix, ws_len)
+
+    @edit_action('comment selection', final=True)
+    @clear_selection
+    def toggle_comment_selection(self, prefix: str) -> None:
+        s_y, e_y = self._selection_lines()
+        commented = self._is_commented(s_y, prefix)
+        minimum_indent = self._minimum_indent_for_selection()
+        for lineno in range(s_y, e_y):
+            if commented:
+                self._comment_remove(lineno, prefix)
+            else:
+                self._comment_add(lineno, prefix, minimum_indent)
 
     DISPATCH = {
         # movement
@@ -768,12 +850,12 @@ class File:
 
     def move_cursor(
             self,
-            stdscr: 'curses._CursesWindow',
+            stdscr: curses._CursesWindow,
             margin: Margin,
     ) -> None:
         stdscr.move(*self.buf.cursor_position(margin))
 
-    def draw(self, stdscr: 'curses._CursesWindow', margin: Margin) -> None:
+    def draw(self, stdscr: curses._CursesWindow, margin: Margin) -> None:
         to_display = min(self.buf.displayable_count, margin.body_lines)
 
         for file_hl in self._file_hls:

babi/highlight.py

@@ -1,13 +1,11 @@
+from __future__ import annotations
+
 import functools
 import json
 import os.path
 from typing import Any
-from typing import Dict
-from typing import FrozenSet
-from typing import List
 from typing import Match
 from typing import NamedTuple
-from typing import Optional
 from typing import Tuple
 from typing import TypeVar
 
@@ -34,7 +32,7 @@ def uniquely_constructed(t: T) -> T:
     return t
 
 
-def _split_name(s: Optional[str]) -> Tuple[str, ...]:
+def _split_name(s: str | None) -> tuple[str, ...]:
     if s is None:
         return ()
     else:
@@ -44,17 +42,17 @@ def _split_name(s: Optional[str]) -> Tuple[str, ...]:
 class _Rule(Protocol):
     """hax for recursive types python/mypy#731"""
     @property
-    def name(self) -> Tuple[str, ...]: ...
+    def name(self) -> tuple[str, ...]: ...
     @property
-    def match(self) -> Optional[str]: ...
+    def match(self) -> str | None: ...
     @property
-    def begin(self) -> Optional[str]: ...
+    def begin(self) -> str | None: ...
     @property
-    def end(self) -> Optional[str]: ...
+    def end(self) -> str | None: ...
     @property
-    def while_(self) -> Optional[str]: ...
+    def while_(self) -> str | None: ...
     @property
-    def content_name(self) -> Tuple[str, ...]: ...
+    def content_name(self) -> tuple[str, ...]: ...
     @property
     def captures(self) -> Captures: ...
     @property
@@ -64,39 +62,39 @@ class _Rule(Protocol):
     @property
     def while_captures(self) -> Captures: ...
     @property
-    def include(self) -> Optional[str]: ...
+    def include(self) -> str | None: ...
     @property
-    def patterns(self) -> 'Tuple[_Rule, ...]': ...
+    def patterns(self) -> tuple[_Rule, ...]: ...
     @property
-    def repository(self) -> 'FChainMap[str, _Rule]': ...
+    def repository(self) -> FChainMap[str, _Rule]: ...
 
 
 @uniquely_constructed
 class Rule(NamedTuple):
-    name: Tuple[str, ...]
-    match: Optional[str]
-    begin: Optional[str]
-    end: Optional[str]
-    while_: Optional[str]
-    content_name: Tuple[str, ...]
+    name: tuple[str, ...]
+    match: str | None
+    begin: str | None
+    end: str | None
+    while_: str | None
+    content_name: tuple[str, ...]
     captures: Captures
     begin_captures: Captures
     end_captures: Captures
     while_captures: Captures
-    include: Optional[str]
-    patterns: Tuple[_Rule, ...]
+    include: str | None
+    patterns: tuple[_Rule, ...]
     repository: FChainMap[str, _Rule]
 
     @classmethod
     def make(
             cls,
-            dct: Dict[str, Any],
+            dct: dict[str, Any],
             parent_repository: FChainMap[str, _Rule],
     ) -> _Rule:
         if 'repository' in dct:
             # this looks odd, but it's so we can have a self-referential
             # immutable-after-construction chain map
-            repository_dct: Dict[str, _Rule] = {}
+            repository_dct: dict[str, _Rule] = {}
             repository = FChainMap(parent_repository, repository_dct)
             for k, sub_dct in dct['repository'].items():
                 repository_dct[k] = Rule.make(sub_dct, repository)
@@ -183,15 +181,15 @@ class Rule(NamedTuple):
 class Grammar(NamedTuple):
     scope_name: str
     repository: FChainMap[str, _Rule]
-    patterns: Tuple[_Rule, ...]
+    patterns: tuple[_Rule, ...]
 
     @classmethod
-    def make(cls, data: Dict[str, Any]) -> 'Grammar':
+    def make(cls, data: dict[str, Any]) -> Grammar:
         scope_name = data['scopeName']
         if 'repository' in data:
             # this looks odd, but it's so we can have a self-referential
             # immutable-after-construction chain map
-            repository_dct: Dict[str, _Rule] = {}
+            repository_dct: dict[str, _Rule] = {}
             repository = FChainMap(repository_dct)
             for k, dct in data['repository'].items():
                 repository_dct[k] = Rule.make(dct, repository)
@@ -212,54 +210,54 @@ class Region(NamedTuple):
 
 
 class State(NamedTuple):
-    entries: Tuple['Entry', ...]
-    while_stack: Tuple[Tuple['WhileRule', int], ...]
+    entries: tuple[Entry, ...]
+    while_stack: tuple[tuple[WhileRule, int], ...]
 
     @classmethod
-    def root(cls, entry: 'Entry') -> 'State':
+    def root(cls, entry: Entry) -> State:
         return cls((entry,), ())
 
     @property
-    def cur(self) -> 'Entry':
+    def cur(self) -> Entry:
         return self.entries[-1]
 
-    def push(self, entry: 'Entry') -> 'State':
+    def push(self, entry: Entry) -> State:
         return self._replace(entries=(*self.entries, entry))
 
-    def pop(self) -> 'State':
+    def pop(self) -> State:
         return self._replace(entries=self.entries[:-1])
 
-    def push_while(self, rule: 'WhileRule', entry: 'Entry') -> 'State':
+    def push_while(self, rule: WhileRule, entry: Entry) -> State:
         entries = (*self.entries, entry)
         while_stack = (*self.while_stack, (rule, len(entries)))
         return self._replace(entries=entries, while_stack=while_stack)
 
-    def pop_while(self) -> 'State':
+    def pop_while(self) -> State:
         entries, while_stack = self.entries[:-1], self.while_stack[:-1]
         return self._replace(entries=entries, while_stack=while_stack)
 
 
 class CompiledRule(Protocol):
     @property
-    def name(self) -> Tuple[str, ...]: ...
+    def name(self) -> tuple[str, ...]: ...
 
     def start(
             self,
-            compiler: 'Compiler',
+            compiler: Compiler,
             match: Match[str],
             state: State,
-    ) -> Tuple[State, bool, Regions]:
+    ) -> tuple[State, bool, Regions]:
         ...
 
     def search(
             self,
-            compiler: 'Compiler',
+            compiler: Compiler,
             state: State,
             line: str,
             pos: int,
             first_line: bool,
             boundary: bool,
-    ) -> Optional[Tuple[State, int, bool, Regions]]:
+    ) -> tuple[State, int, bool, Regions] | None:
         ...
 
 
@@ -267,24 +265,25 @@ class CompiledRegsetRule(CompiledRule, Protocol):
     @property
     def regset(self) -> _RegSet: ...
     @property
-    def u_rules(self) -> Tuple[_Rule, ...]: ...
+    def u_rules(self) -> tuple[_Rule, ...]: ...
 
 
 class Entry(NamedTuple):
-    scope: Tuple[str, ...]
+    scope: tuple[str, ...]
     rule: CompiledRule
+    start: tuple[str, int]
     reg: _Reg = ERR_REG
     boundary: bool = False
 
 
 def _inner_capture_parse(
-        compiler: 'Compiler',
+        compiler: Compiler,
         start: int,
         s: str,
         scope: Scope,
         rule: CompiledRule,
 ) -> Regions:
-    state = State.root(Entry(scope + rule.name, rule))
+    state = State.root(Entry(scope + rule.name, rule, (s, 0)))
     _, regions = highlight_line(compiler, state, s, first_line=False)
     return tuple(
         r._replace(start=r.start + start, end=r.end + start) for r in regions
@@ -292,12 +291,12 @@ def _inner_capture_parse(
 
 
 def _captures(
-        compiler: 'Compiler',
+        compiler: Compiler,
         scope: Scope,
         match: Match[str],
         captures: Captures,
 ) -> Regions:
-    ret: List[Region] = []
+    ret: list[Region] = []
     pos, pos_end = match.span()
     for i, u_rule in captures:
         try:
@@ -346,12 +345,12 @@ def _captures(
 
 def _do_regset(
         idx: int,
-        match: Optional[Match[str]],
+        match: Match[str] | None,
         rule: CompiledRegsetRule,
-        compiler: 'Compiler',
+        compiler: Compiler,
         state: State,
         pos: int,
-) -> Optional[Tuple[State, int, bool, Regions]]:
+) -> tuple[State, int, bool, Regions] | None:
     if match is None:
         return None
 
@@ -368,104 +367,114 @@ def _do_regset(
 
 @uniquely_constructed
 class PatternRule(NamedTuple):
-    name: Tuple[str, ...]
+    name: tuple[str, ...]
     regset: _RegSet
-    u_rules: Tuple[_Rule, ...]
+    u_rules: tuple[_Rule, ...]
 
     def start(
             self,
-            compiler: 'Compiler',
+            compiler: Compiler,
             match: Match[str],
             state: State,
-    ) -> Tuple[State, bool, Regions]:
+    ) -> tuple[State, bool, Regions]:
         raise AssertionError(f'unreachable {self}')
 
     def search(
             self,
-            compiler: 'Compiler',
+            compiler: Compiler,
             state: State,
             line: str,
             pos: int,
             first_line: bool,
             boundary: bool,
-    ) -> Optional[Tuple[State, int, bool, Regions]]:
+    ) -> tuple[State, int, bool, Regions] | None:
         idx, match = self.regset.search(line, pos, first_line, boundary)
         return _do_regset(idx, match, self, compiler, state, pos)
 
 
 @uniquely_constructed
 class MatchRule(NamedTuple):
-    name: Tuple[str, ...]
+    name: tuple[str, ...]
     captures: Captures
 
     def start(
             self,
-            compiler: 'Compiler',
+            compiler: Compiler,
             match: Match[str],
             state: State,
-    ) -> Tuple[State, bool, Regions]:
+    ) -> tuple[State, bool, Regions]:
         scope = state.cur.scope + self.name
         return state, False, _captures(compiler, scope, match, self.captures)
 
     def search(
             self,
-            compiler: 'Compiler',
+            compiler: Compiler,
             state: State,
             line: str,
             pos: int,
             first_line: bool,
             boundary: bool,
-    ) -> Optional[Tuple[State, int, bool, Regions]]:
+    ) -> tuple[State, int, bool, Regions] | None:
         raise AssertionError(f'unreachable {self}')
 
 
 @uniquely_constructed
 class EndRule(NamedTuple):
-    name: Tuple[str, ...]
-    content_name: Tuple[str, ...]
+    name: tuple[str, ...]
+    content_name: tuple[str, ...]
     begin_captures: Captures
     end_captures: Captures
     end: str
     regset: _RegSet
-    u_rules: Tuple[_Rule, ...]
+    u_rules: tuple[_Rule, ...]
 
     def start(
             self,
-            compiler: 'Compiler',
+            compiler: Compiler,
             match: Match[str],
             state: State,
-    ) -> Tuple[State, bool, Regions]:
+    ) -> tuple[State, bool, Regions]:
         scope = state.cur.scope + self.name
         next_scope = scope + self.content_name
 
         boundary = match.end() == len(match.string)
         reg = make_reg(expand_escaped(match, self.end))
-        state = state.push(Entry(next_scope, self, reg, boundary))
+        start = (match.string, match.start())
+        state = state.push(Entry(next_scope, self, start, reg, boundary))
         regions = _captures(compiler, scope, match, self.begin_captures)
         return state, True, regions
 
     def _end_ret(
             self,
-            compiler: 'Compiler',
+            compiler: Compiler,
             state: State,
             pos: int,
             m: Match[str],
-    ) -> Tuple[State, int, bool, Regions]:
+    ) -> tuple[State, int, bool, Regions]:
         ret = []
         if m.start() > pos:
             ret.append(Region(pos, m.start(), state.cur.scope))
         ret.extend(_captures(compiler, state.cur.scope, m, self.end_captures))
-        return state.pop(), m.end(), False, tuple(ret)
+        # this is probably a bug in the grammar, but it pushed and popped at
+        # the same position.
+        # we'll advance the highlighter by one position to get past the loop
+        # this appears to be what vs code does as well
+        if state.entries[-1].start == (m.string, m.end()):
+            ret.append(Region(m.end(), m.end() + 1, state.cur.scope))
+            end = m.end() + 1
+        else:
+            end = m.end()
+        return state.pop(), end, False, tuple(ret)
 
     def search(
             self,
-            compiler: 'Compiler',
+            compiler: Compiler,
             state: State,
             line: str,
             pos: int,
             first_line: bool,
             boundary: bool,
-    ) -> Optional[Tuple[State, int, bool, Regions]]:
+    ) -> tuple[State, int, bool, Regions] | None:
         end_match = state.cur.reg.search(line, pos, first_line, boundary)
         if end_match is not None and end_match.start() == pos:
             return self._end_ret(compiler, state, pos, end_match)
@@ -482,38 +491,40 @@ class EndRule(NamedTuple):
 
 @uniquely_constructed
 class WhileRule(NamedTuple):
-    name: Tuple[str, ...]
-    content_name: Tuple[str, ...]
+    name: tuple[str, ...]
+    content_name: tuple[str, ...]
     begin_captures: Captures
     while_captures: Captures
     while_: str
     regset: _RegSet
-    u_rules: Tuple[_Rule, ...]
+    u_rules: tuple[_Rule, ...]
 
     def start(
             self,
-            compiler: 'Compiler',
+            compiler: Compiler,
             match: Match[str],
             state: State,
-    ) -> Tuple[State, bool, Regions]:
+    ) -> tuple[State, bool, Regions]:
         scope = state.cur.scope + self.name
         next_scope = scope + self.content_name
 
         boundary = match.end() == len(match.string)
         reg = make_reg(expand_escaped(match, self.while_))
-        state = state.push_while(self, Entry(next_scope, self, reg, boundary))
+        start = (match.string, match.start())
+        entry = Entry(next_scope, self, start, reg, boundary)
+        state = state.push_while(self, entry)
         regions = _captures(compiler, scope, match, self.begin_captures)
         return state, True, regions
 
     def continues(
             self,
-            compiler: 'Compiler',
+            compiler: Compiler,
             state: State,
             line: str,
             pos: int,
             first_line: bool,
             boundary: bool,
-    ) -> Optional[Tuple[int, bool, Regions]]:
+    ) -> tuple[int, bool, Regions] | None:
         match = state.cur.reg.match(line, pos, first_line, boundary)
         if match is None:
             return None
@@ -523,25 +534,25 @@ class WhileRule(NamedTuple):
 
     def search(
             self,
-            compiler: 'Compiler',
+            compiler: Compiler,
             state: State,
             line: str,
             pos: int,
             first_line: bool,
             boundary: bool,
-    ) -> Optional[Tuple[State, int, bool, Regions]]:
+    ) -> tuple[State, int, bool, Regions] | None:
         idx, match = self.regset.search(line, pos, first_line, boundary)
         return _do_regset(idx, match, self, compiler, state, pos)
 
 
 class Compiler:
-    def __init__(self, grammar: Grammar, grammars: 'Grammars') -> None:
+    def __init__(self, grammar: Grammar, grammars: Grammars) -> None:
         self._root_scope = grammar.scope_name
         self._grammars = grammars
-        self._rule_to_grammar: Dict[_Rule, Grammar] = {}
-        self._c_rules: Dict[_Rule, CompiledRule] = {}
+        self._rule_to_grammar: dict[_Rule, Grammar] = {}
+        self._c_rules: dict[_Rule, CompiledRule] = {}
         root = self._compile_root(grammar)
-        self.root_state = State.root(Entry(root.name, root))
+        self.root_state = State.root(Entry(root.name, root, ('', 0)))
 
     def _visit_rule(self, grammar: Grammar, rule: _Rule) -> _Rule:
         self._rule_to_grammar[rule] = grammar
@@ -553,7 +564,7 @@ class Compiler:
             grammar: Grammar,
             repository: FChainMap[str, _Rule],
             s: str,
-    ) -> Tuple[List[str], Tuple[_Rule, ...]]:
+    ) -> tuple[list[str], tuple[_Rule, ...]]:
         if s == '$self':
             return self._patterns(grammar, grammar.patterns)
         elif s == '$base':
@@ -573,10 +584,10 @@ class Compiler:
     def _patterns(
             self,
             grammar: Grammar,
-            rules: Tuple[_Rule, ...],
-    ) -> Tuple[List[str], Tuple[_Rule, ...]]:
+            rules: tuple[_Rule, ...],
+    ) -> tuple[list[str], tuple[_Rule, ...]]:
         ret_regs = []
-        ret_rules: List[_Rule] = []
+        ret_rules: list[_Rule] = []
         for rule in rules:
             if rule.include is not None:
                 tmp_regs, tmp_rules = self._include(
@@ -663,19 +674,19 @@ class Grammars:
 
         unknown_grammar = {'scopeName': 'source.unknown', 'patterns': []}
         self._raw = {'source.unknown': unknown_grammar}
-        self._file_types: List[Tuple[FrozenSet[str], str]] = []
-        self._first_line: List[Tuple[_Reg, str]] = []
-        self._parsed: Dict[str, Grammar] = {}
-        self._compiled: Dict[str, Compiler] = {}
+        self._file_types: list[tuple[frozenset[str], str]] = []
+        self._first_line: list[tuple[_Reg, str]] = []
+        self._parsed: dict[str, Grammar] = {}
+        self._compiled: dict[str, Compiler] = {}
 
-    def _raw_for_scope(self, scope: str) -> Dict[str, Any]:
+    def _raw_for_scope(self, scope: str) -> dict[str, Any]:
         try:
             return self._raw[scope]
         except KeyError:
             pass
 
         grammar_path = self._scope_to_files.pop(scope)
-        with open(grammar_path) as f:
+        with open(grammar_path, encoding='UTF-8') as f:
             ret = self._raw[scope] = json.load(f)
 
         file_types = frozenset(ret.get('fileTypes', ()))
@@ -734,12 +745,12 @@ class Grammars:
 
 
 def highlight_line(
-        compiler: 'Compiler',
+        compiler: Compiler,
         state: State,
         line: str,
         first_line: bool,
-) -> Tuple[State, Regions]:
-    ret: List[Region] = []
+) -> tuple[State, Regions]:
+    ret: list[Region] = []
     pos = 0
     boundary = state.cur.boundary
 

babi/history.py

@@ -1,25 +1,26 @@
+from __future__ import annotations
+
 import collections
 import contextlib
 import os.path
-from typing import Dict
 from typing import Generator
-from typing import List
 
 from babi.user_data import xdg_data
 
 
 class History:
     def __init__(self) -> None:
-        self._orig_len: Dict[str, int] = collections.defaultdict(int)
-        self.data: Dict[str, List[str]] = collections.defaultdict(list)
-        self.prev: Dict[str, str] = {}
+        self._orig_len: dict[str, int] = collections.defaultdict(int)
+        self.data: dict[str, list[str]] = collections.defaultdict(list)
+        self.prev: dict[str, str] = {}
 
     @contextlib.contextmanager
     def save(self) -> Generator[None, None, None]:
         history_dir = xdg_data('history')
         os.makedirs(history_dir, exist_ok=True)
         for filename in os.listdir(history_dir):
-            with open(os.path.join(history_dir, filename)) as f:
+            history_filename = os.path.join(history_dir, filename)
+            with open(history_filename, encoding='UTF-8') as f:
                 self.data[filename] = f.read().splitlines()
                 self._orig_len[filename] = len(self.data[filename])
         try:
@@ -28,5 +29,6 @@ class History:
             for k, v in self.data.items():
                 new_history = v[self._orig_len[k]:]
                 if new_history:
-                    with open(os.path.join(history_dir, k), 'a+') as f:
+                    history_filename = os.path.join(history_dir, k)
+                    with open(history_filename, 'a+', encoding='UTF-8') as f:
                         f.write('\n'.join(new_history) + '\n')

babi/hl/interface.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from typing import NamedTuple
 from typing import Tuple
 

babi/hl/replace.py

@@ -1,7 +1,8 @@
+from __future__ import annotations
+
 import collections
 import contextlib
 import curses
-from typing import Dict
 from typing import Generator
 
 from babi.buf import Buf
@@ -13,7 +14,7 @@ class Replace:
     include_edge = True
 
     def __init__(self) -> None:
-        self.regions: Dict[int, HLs] = collections.defaultdict(tuple)
+        self.regions: dict[int, HLs] = collections.defaultdict(tuple)
 
     def highlight_until(self, lines: Buf, idx: int) -> None:
         """our highlight regions are populated in other ways"""

babi/hl/selection.py

@@ -1,8 +1,7 @@
+from __future__ import annotations
+
 import collections
 import curses
-from typing import Dict
-from typing import Optional
-from typing import Tuple
 
 from babi.buf import Buf
 from babi.hl.interface import HL
@@ -13,9 +12,9 @@ class Selection:
     include_edge = True
 
     def __init__(self) -> None:
-        self.regions: Dict[int, HLs] = collections.defaultdict(tuple)
-        self.start: Optional[Tuple[int, int]] = None
-        self.end: Optional[Tuple[int, int]] = None
+        self.regions: dict[int, HLs] = collections.defaultdict(tuple)
+        self.start: tuple[int, int] | None = None
+        self.end: tuple[int, int] | None = None
 
     def register_callbacks(self, buf: Buf) -> None:
         """our highlight regions are populated in other ways"""
@@ -39,7 +38,7 @@ class Selection:
                 )
             self.regions[e_y] = (HL(x=0, end=e_x, attr=attr),)
 
-    def get(self) -> Tuple[Tuple[int, int], Tuple[int, int]]:
+    def get(self) -> tuple[tuple[int, int], tuple[int, int]]:
         assert self.start is not None and self.end is not None
         if self.start < self.end:
             return self.start, self.end

babi/hl/syntax.py

@@ -1,11 +1,10 @@
+from __future__ import annotations
+
 import curses
 import functools
 import math
 from typing import Callable
-from typing import List
 from typing import NamedTuple
-from typing import Optional
-from typing import Tuple
 
 from babi.buf import Buf
 from babi.color_manager import ColorManager
@@ -21,7 +20,7 @@ from babi.user_data import prefix_data
 from babi.user_data import xdg_config
 from babi.user_data import xdg_data
 
-A_ITALIC = getattr(curses, 'A_ITALIC', 0x80000000)  # new in py37
+A_ITALIC = getattr(curses, 'A_ITALIC', 0x80000000)  # not always present
 
 
 class FileSyntax:
@@ -37,12 +36,12 @@ class FileSyntax:
         self._theme = theme
         self._color_manager = color_manager
 
-        self.regions: List[HLs] = []
-        self._states: List[State] = []
+        self.regions: list[HLs] = []
+        self._states: list[State] = []
 
         # this will be assigned a functools.lru_cache per instance for
         # better hit rate and memory usage
-        self._hl: Optional[Callable[[State, str, bool], Tuple[State, HLs]]]
+        self._hl: Callable[[State, str, bool], tuple[State, HLs]] | None
         self._hl = None
 
     def attr(self, style: Style) -> int:
@@ -59,7 +58,7 @@ class FileSyntax:
             state: State,
             line: str,
             first_line: bool,
-    ) -> Tuple[State, HLs]:
+    ) -> tuple[State, HLs]:
         new_state, regions = highlight_line(
             self._compiler, state, f'{line}\n', first_line=first_line,
         )
@@ -68,7 +67,7 @@ class FileSyntax:
         new_end = regions[-1]._replace(end=regions[-1].end - 1)
         regions = regions[:-1] + (new_end,)
 
-        regs: List[HL] = []
+        regs: list[HL] = []
         for r in regions:
             style = self._theme.select(r.scope)
             if style == self._theme.default:
@@ -115,8 +114,7 @@ class FileSyntax:
             state = self._states[-1]
 
         for i in range(len(self._states), idx):
-            # https://github.com/python/mypy/issues/8579
-            state, regions = self._hl(state, lines[i], i == 0)  # type: ignore
+            state, regions = self._hl(state, lines[i], i == 0)
             self._states.append(state)
             self.regions.append(regions)
 
@@ -134,7 +132,7 @@ class Syntax(NamedTuple):
         compiler = self.grammars.blank_compiler()
         return FileSyntax(compiler, self.theme, self.color_manager)
 
-    def _init_screen(self, stdscr: 'curses._CursesWindow') -> None:
+    def _init_screen(self, stdscr: curses._CursesWindow) -> None:
         default_fg, default_bg = self.theme.default.fg, self.theme.default.bg
         all_colors = {c for c in (default_fg, default_bg) if c is not None}
         todo = list(self.theme.rules.children.values())
@@ -155,9 +153,9 @@ class Syntax(NamedTuple):
     @classmethod
     def from_screen(
             cls,
-            stdscr: 'curses._CursesWindow',
+            stdscr: curses._CursesWindow,
             color_manager: ColorManager,
-    ) -> 'Syntax':
+    ) -> Syntax:
         grammars = Grammars(prefix_data('grammar_v1'), xdg_data('grammar_v1'))
         theme = Theme.from_filename(xdg_config('theme.json'))
         ret = cls(grammars, theme, color_manager)

babi/hl/trailing_whitespace.py

@@ -1,5 +1,6 @@
+from __future__ import annotations
+
 import curses
-from typing import List
 
 from babi.buf import Buf
 from babi.color_manager import ColorManager
@@ -13,7 +14,7 @@ class TrailingWhitespace:
     def __init__(self, color_manager: ColorManager) -> None:
         self._color_manager = color_manager
 
-        self.regions: List[HLs] = []
+        self.regions: list[HLs] = []
 
     def _trailing_ws(self, line: str) -> HLs:
         if not line:

babi/horizontal_scrolling.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import curses
 
 from babi.cached_property import cached_property
@@ -34,7 +36,7 @@ def scrolled_line(s: str, x: int, width: int) -> str:
 
 class _CalcWidth:
     @cached_property
-    def _window(self) -> 'curses._CursesWindow':
+    def _window(self) -> curses._CursesWindow:
         return curses.newwin(1, 10)
 
     def wcwidth(self, c: str) -> int:

babi/main.py

@@ -1,8 +1,11 @@
+from __future__ import annotations
+
 import argparse
 import curses
 import os
+import re
+import signal
 import sys
-from typing import Optional
 from typing import Sequence
 
 from babi.buf import Buf
@@ -14,10 +17,11 @@ from babi.screen import make_stdscr
 from babi.screen import Screen
 
 CONSOLE = 'CONIN$' if sys.platform == 'win32' else '/dev/tty'
+POSITION_RE = re.compile(r'^\+-?\d+$')
 
 
 def _edit(screen: Screen, stdin: str) -> EditResult:
-    screen.file.ensure_loaded(screen.status, stdin)
+    screen.file.ensure_loaded(screen.status, screen.margin, stdin)
 
     while True:
         screen.status.tick(screen.margin)
@@ -39,36 +43,37 @@ def _edit(screen: Screen, stdin: str) -> EditResult:
 
 
 def c_main(
-        stdscr: 'curses._CursesWindow',
-        args: argparse.Namespace,
+        stdscr: curses._CursesWindow,
+        filenames: list[str | None],
+        positions: list[int],
         stdin: str,
+        perf: Perf,
 ) -> int:
-    with perf_log(args.perf_log) as perf:
-        screen = Screen(stdscr, args.filenames or [None], perf)
-        with screen.history.save():
-            while screen.files:
-                screen.i = screen.i % len(screen.files)
-                res = _edit(screen, stdin)
-                if res == EditResult.EXIT:
-                    del screen.files[screen.i]
-                    # always go to the next file except at the end
-                    screen.i = min(screen.i, len(screen.files) - 1)
-                    screen.status.clear()
-                elif res == EditResult.NEXT:
-                    screen.i += 1
-                    screen.status.clear()
-                elif res == EditResult.PREV:
-                    screen.i -= 1
-                    screen.status.clear()
-                elif res == EditResult.OPEN:
-                    screen.i = len(screen.files) - 1
-                else:
-                    raise AssertionError(f'unreachable {res}')
+    screen = Screen(stdscr, filenames, positions, perf)
+    with screen.history.save():
+        while screen.files:
+            screen.i = screen.i % len(screen.files)
+            res = _edit(screen, stdin)
+            if res == EditResult.EXIT:
+                del screen.files[screen.i]
+                # always go to the next file except at the end
+                screen.i = min(screen.i, len(screen.files) - 1)
+                screen.status.clear()
+            elif res == EditResult.NEXT:
+                screen.i += 1
+                screen.status.clear()
+            elif res == EditResult.PREV:
+                screen.i -= 1
+                screen.status.clear()
+            elif res == EditResult.OPEN:
+                screen.i = len(screen.files) - 1
+            else:
+                raise AssertionError(f'unreachable {res}')
     return 0
 
 
-def _key_debug(stdscr: 'curses._CursesWindow') -> int:
-    screen = Screen(stdscr, ['<<key debug>>'], Perf())
+def _key_debug(stdscr: curses._CursesWindow, perf: Perf) -> int:
+    screen = Screen(stdscr, ['<<key debug>>'], [0], perf)
     screen.file.buf = Buf([''])
 
     while True:
@@ -85,7 +90,38 @@ def _key_debug(stdscr: 'curses._CursesWindow') -> int:
             return 0
 
 
-def main(argv: Optional[Sequence[str]] = None) -> int:
+def _filenames(filenames: list[str]) -> tuple[list[str | None], list[int]]:
+    if not filenames:
+        return [None], [0]
+
+    ret_filenames: list[str | None] = []
+    ret_positions = []
+
+    filenames_iter = iter(filenames)
+    for filename in filenames_iter:
+        if POSITION_RE.match(filename):
+            # in the success case we get:
+            #
+            # position_s = +...
+            # filename = (the next thing)
+            #
+            # in the error case we only need to reset `position_s` as
+            # `filename` is already correct
+            position_s = filename
+            try:
+                filename = next(filenames_iter)
+            except StopIteration:
+                position_s = '+0'
+            ret_positions.append(int(position_s[1:]))
+            ret_filenames.append(filename)
+        else:
+            ret_positions.append(0)
+            ret_filenames.append(filename)
+
+    return ret_filenames, ret_positions
+
+
+def main(argv: Sequence[str] | None = None) -> int:
     parser = argparse.ArgumentParser()
     parser.add_argument('filenames', metavar='filename', nargs='*')
     parser.add_argument('--perf-log')
@@ -96,18 +132,24 @@ def main(argv: Optional[Sequence[str]] = None) -> int:
 
     if '-' in args.filenames:
         print('reading stdin...', file=sys.stderr)
-        stdin = sys.stdin.read()
+        stdin = sys.stdin.buffer.read().decode()
         tty = os.open(CONSOLE, os.O_RDONLY)
         os.dup2(tty, sys.stdin.fileno())
     else:
         stdin = ''
 
-    with make_stdscr() as stdscr:
+    # ignore backgrounding signals, we'll handle those in curses
+    # fixes a problem with ^Z on termination which would break the terminal
+    if sys.platform != 'win32':  # pragma: win32 no cover  # pragma: no branch
+        signal.signal(signal.SIGTSTP, signal.SIG_IGN)
+
+    with perf_log(args.perf_log) as perf, make_stdscr() as stdscr:
         if args.key_debug:
-            return _key_debug(stdscr)
+            return _key_debug(stdscr, perf)
         else:
-            return c_main(stdscr, args, stdin)
+            filenames, positions = _filenames(args.filenames)
+            return c_main(stdscr, filenames, positions, stdin, perf)
 
 
 if __name__ == '__main__':
-    exit(main())
+    raise SystemExit(main())

babi/margin.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import curses
 from typing import NamedTuple
 
@@ -31,5 +33,5 @@ class Margin(NamedTuple):
         return int(self.lines / 2 + .5)
 
     @classmethod
-    def from_current_screen(cls) -> 'Margin':
+    def from_current_screen(cls) -> Margin:
         return cls(curses.LINES, curses.COLS)

babi/perf.py

@@ -1,18 +1,17 @@
+from __future__ import annotations
+
 import contextlib
 import cProfile
 import time
 from typing import Generator
-from typing import List
-from typing import Optional
-from typing import Tuple
 
 
 class Perf:
     def __init__(self) -> None:
-        self._prof: Optional[cProfile.Profile] = None
-        self._records: List[Tuple[str, float]] = []
-        self._name: Optional[str] = None
-        self._time: Optional[float] = None
+        self._prof: cProfile.Profile | None = None
+        self._records: list[tuple[str, float]] = []
+        self._name: str | None = None
+        self._time: float | None = None
 
     def start(self, name: str) -> None:
         if self._prof:
@@ -36,14 +35,14 @@ class Perf:
     def save_profiles(self, filename: str) -> None:
         assert self._prof is not None
         self._prof.dump_stats(f'{filename}.pstats')
-        with open(filename, 'w') as f:
+        with open(filename, 'w', encoding='UTF-8') as f:
             f.write('μs\tevent\n')
             for name, duration in self._records:
                 f.write(f'{int(duration * 1000 * 1000)}\t{name}\n')
 
 
 @contextlib.contextmanager
-def perf_log(filename: Optional[str]) -> Generator[Perf, None, None]:
+def perf_log(filename: str | None) -> Generator[Perf, None, None]:
     perf = Perf()
     if filename is None:
         yield perf

babi/prompt.py

@@ -1,10 +1,8 @@
+from __future__ import annotations
+
 import curses
 import enum
-from typing import List
-from typing import Optional
-from typing import Tuple
 from typing import TYPE_CHECKING
-from typing import Union
 
 from babi.horizontal_scrolling import line_x
 from babi.horizontal_scrolling import scrolled_line
@@ -16,7 +14,7 @@ PromptResult = enum.Enum('PromptResult', 'CANCELLED')
 
 
 class Prompt:
-    def __init__(self, screen: 'Screen', prompt: str, lst: List[str]) -> None:
+    def __init__(self, screen: Screen, prompt: str, lst: list[str]) -> None:
         self._screen = screen
         self._prompt = prompt
         self._lst = lst
@@ -31,7 +29,7 @@ class Prompt:
     def _s(self, s: str) -> None:
         self._lst[self._y] = s
 
-    def _render_prompt(self, *, base: Optional[str] = None) -> None:
+    def _render_prompt(self, *, base: str | None = None) -> None:
         base = base or self._prompt
         if not base or self._screen.margin.cols < 7:
             prompt_s = ''
@@ -100,7 +98,7 @@ class Prompt:
     def _resize(self) -> None:
         self._screen.resize()
 
-    def _check_failed(self, idx: int, s: str) -> Tuple[bool, int]:
+    def _check_failed(self, idx: int, s: str) -> tuple[bool, int]:
         failed = False
         for search_idx in range(idx, -1, -1):
             if s in self._lst[search_idx]:
@@ -111,7 +109,7 @@ class Prompt:
             failed = True
         return failed, idx
 
-    def _reverse_search(self) -> Union[None, str, PromptResult]:
+    def _reverse_search(self) -> None | str | PromptResult:
         reverse_s = ''
         idx = self._y
         while True:
@@ -177,7 +175,7 @@ class Prompt:
         self._s = self._s[:self._x] + c + self._s[self._x:]
         self._x += len(c)
 
-    def run(self) -> Union[PromptResult, str]:
+    def run(self) -> PromptResult | str:
         while True:
             self._render_prompt()
 

babi/reg.py

@@ -1,93 +1,49 @@
+from __future__ import annotations
+
 import functools
 import re
 from typing import Match
-from typing import Optional
-from typing import Tuple
 
 import onigurumacffi
 
-from babi.cached_property import cached_property
-
 _BACKREF_RE = re.compile(r'((?<!\\)(?:\\\\)*)\\([0-9]+)')
 
 
-def _replace_esc(s: str, chars: str) -> str:
-    """replace the given escape sequences of `chars` with \\uffff"""
-    for c in chars:
-        if f'\\{c}' in s:
-            break
-    else:
-        return s
-
-    b = []
-    i = 0
-    length = len(s)
-    while i < length:
-        try:
-            sbi = s.index('\\', i)
-        except ValueError:
-            b.append(s[i:])
-            break
-        if sbi > i:
-            b.append(s[i:sbi])
-        b.append('\\')
-        i = sbi + 1
-        if i < length:
-            if s[i] in chars:
-                b.append('\uffff')
-            else:
-                b.append(s[i])
-        i += 1
-    return ''.join(b)
+_FLAGS = {
+    # (first_line, boundary)
+    (False, False): (
+        onigurumacffi.OnigSearchOption.NOT_END_STRING |
+        onigurumacffi.OnigSearchOption.NOT_BEGIN_STRING |
+        onigurumacffi.OnigSearchOption.NOT_BEGIN_POSITION
+    ),
+    (False, True): (
+        onigurumacffi.OnigSearchOption.NOT_END_STRING |
+        onigurumacffi.OnigSearchOption.NOT_BEGIN_STRING
+    ),
+    (True, False): (
+        onigurumacffi.OnigSearchOption.NOT_END_STRING |
+        onigurumacffi.OnigSearchOption.NOT_BEGIN_POSITION
+    ),
+    (True, True): onigurumacffi.OnigSearchOption.NOT_END_STRING,
+}
 
 
 class _Reg:
     def __init__(self, s: str) -> None:
         self._pattern = s
+        self._reg = onigurumacffi.compile(self._pattern)
 
     def __repr__(self) -> str:
         return f'{type(self).__name__}({self._pattern!r})'
 
-    @cached_property
-    def _reg(self) -> onigurumacffi._Pattern:
-        return onigurumacffi.compile(_replace_esc(self._pattern, 'z'))
-
-    @cached_property
-    def _reg_no_A(self) -> onigurumacffi._Pattern:
-        return onigurumacffi.compile(_replace_esc(self._pattern, 'Az'))
-
-    @cached_property
-    def _reg_no_G(self) -> onigurumacffi._Pattern:
-        return onigurumacffi.compile(_replace_esc(self._pattern, 'Gz'))
-
-    @cached_property
-    def _reg_no_A_no_G(self) -> onigurumacffi._Pattern:
-        return onigurumacffi.compile(_replace_esc(self._pattern, 'AGz'))
-
-    def _get_reg(
-            self,
-            first_line: bool,
-            boundary: bool,
-    ) -> onigurumacffi._Pattern:
-        if boundary:
-            if first_line:
-                return self._reg
-            else:
-                return self._reg_no_A
-        else:
-            if first_line:
-                return self._reg_no_G
-            else:
-                return self._reg_no_A_no_G
-
     def search(
             self,
             line: str,
             pos: int,
             first_line: bool,
             boundary: bool,
-    ) -> Optional[Match[str]]:
-        return self._get_reg(first_line, boundary).search(line, pos)
+    ) -> Match[str] | None:
+        return self._reg.search(line, pos, flags=_FLAGS[first_line, boundary])
 
     def match(
             self,
@@ -95,54 +51,27 @@ class _Reg:
             pos: int,
             first_line: bool,
             boundary: bool,
-    ) -> Optional[Match[str]]:
-        return self._get_reg(first_line, boundary).match(line, pos)
+    ) -> Match[str] | None:
+        return self._reg.match(line, pos, flags=_FLAGS[first_line, boundary])
 
 
 class _RegSet:
     def __init__(self, *s: str) -> None:
         self._patterns = s
+        self._set = onigurumacffi.compile_regset(*self._patterns)
 
     def __repr__(self) -> str:
         args = ', '.join(repr(s) for s in self._patterns)
         return f'{type(self).__name__}({args})'
 
-    @cached_property
-    def _set(self) -> onigurumacffi._RegSet:
-        return onigurumacffi.compile_regset(*self._patterns)
-
-    @cached_property
-    def _set_no_A(self) -> onigurumacffi._RegSet:
-        patterns = (_replace_esc(p, 'A') for p in self._patterns)
-        return onigurumacffi.compile_regset(*patterns)
-
-    @cached_property
-    def _set_no_G(self) -> onigurumacffi._RegSet:
-        patterns = (_replace_esc(p, 'G') for p in self._patterns)
-        return onigurumacffi.compile_regset(*patterns)
-
-    @cached_property
-    def _set_no_A_no_G(self) -> onigurumacffi._RegSet:
-        patterns = (_replace_esc(p, 'AG') for p in self._patterns)
-        return onigurumacffi.compile_regset(*patterns)
-
     def search(
             self,
             line: str,
             pos: int,
             first_line: bool,
             boundary: bool,
-    ) -> Tuple[int, Optional[Match[str]]]:
-        if boundary:
-            if first_line:
-                return self._set.search(line, pos)
-            else:
-                return self._set_no_A.search(line, pos)
-        else:
-            if first_line:
-                return self._set_no_G.search(line, pos)
-            else:
-                return self._set_no_A_no_G.search(line, pos)
+    ) -> tuple[int, Match[str] | None]:
+        return self._set.search(line, pos, flags=_FLAGS[first_line, boundary])
 
 
 def expand_escaped(match: Match[str], s: str) -> str:
@@ -151,4 +80,4 @@ def expand_escaped(match: Match[str], s: str) -> str:
 
 make_reg = functools.lru_cache(maxsize=None)(_Reg)
 make_regset = functools.lru_cache(maxsize=None)(_RegSet)
-ERR_REG = make_reg(')this pattern always triggers an error when used(')
+ERR_REG = make_reg('$ ^')

babi/screen.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import contextlib
 import curses
 import enum
@@ -5,14 +7,11 @@ import hashlib
 import os
 import re
 import signal
+import sre_parse
 import sys
 from typing import Generator
-from typing import List
 from typing import NamedTuple
-from typing import Optional
 from typing import Pattern
-from typing import Tuple
-from typing import Union
 
 from babi.color_manager import ColorManager
 from babi.file import Action
@@ -38,6 +37,8 @@ EditResult = enum.Enum('EditResult', 'EXIT NEXT PREV OPEN')
 SEQUENCE_KEYNAME = {
     '\x1bOH': b'KEY_HOME',
     '\x1bOF': b'KEY_END',
+    '\x1b[1~': b'KEY_HOME',
+    '\x1b[4~': b'KEY_END',
     '\x1b[1;2A': b'KEY_SR',
     '\x1b[1;2B': b'KEY_SF',
     '\x1b[1;2C': b'KEY_SRIGHT',
@@ -60,6 +61,7 @@ SEQUENCE_KEYNAME = {
     '\x1b[1;6D': b'kLFT6',  # Shift + ^Left
     '\x1b[1;6H': b'kHOM6',  # Shift + ^Home
     '\x1b[1;6F': b'kEND6',  # Shift + ^End
+    '\x1b[~': b'KEY_BTAB',  # Shift + Tab
 }
 KEYNAME_REWRITE = {
     # windows-curses: numeric pad arrow keys
@@ -81,8 +83,11 @@ KEYNAME_REWRITE = {
     b'CTL_DOWN': b'kDN5',
     b'CTL_RIGHT': b'kRIT5',
     b'CTL_LEFT': b'kLFT5',
+    b'CTL_HOME': b'kHOM5',
+    b'CTL_END': b'kEND5',
     b'ALT_RIGHT': b'kRIT3',
     b'ALT_LEFT': b'kLFT3',
+    b'ALT_E': b'M-e',
     # windows-curses: idk why these are different
     b'KEY_SUP': b'KEY_SR',
     b'KEY_SDOWN': b'KEY_SF',
@@ -90,36 +95,39 @@ KEYNAME_REWRITE = {
     b'^?': b'KEY_BACKSPACE',
     # linux, perhaps others
     b'^H': b'KEY_BACKSPACE',  # ^Backspace on my keyboard
+    b'^D': b'KEY_DC',
+    b'PADENTER': b'^M',  # Enter on numpad
 }
 
 
 class Key(NamedTuple):
-    wch: Union[int, str]
+    wch: int | str
     keyname: bytes
 
 
 class Screen:
     def __init__(
             self,
-            stdscr: 'curses._CursesWindow',
-            filenames: List[Optional[str]],
+            stdscr: curses._CursesWindow,
+            filenames: list[str | None],
+            initial_lines: list[int],
             perf: Perf,
     ) -> None:
         self.stdscr = stdscr
         self.color_manager = ColorManager.make()
         self.hl_factories = (Syntax.from_screen(stdscr, self.color_manager),)
         self.files = [
-            File(filename, self.color_manager, self.hl_factories)
-            for filename in filenames
+            File(filename, line, self.color_manager, self.hl_factories)
+            for filename, line in zip(filenames, initial_lines)
         ]
         self.i = 0
         self.history = History()
         self.perf = perf
         self.status = Status()
         self.margin = Margin.from_current_screen()
-        self.cut_buffer: Tuple[str, ...] = ()
+        self.cut_buffer: tuple[str, ...] = ()
         self.cut_selection = False
-        self._buffered_input: Union[int, str, None] = None
+        self._buffered_input: int | str | None = None
 
     @property
     def file(self) -> File:
@@ -221,7 +229,10 @@ class Screen:
         if self._buffered_input is not None:
             wch, self._buffered_input = self._buffered_input, None
         else:
-            wch = self.stdscr.get_wch()
+            try:
+                wch = self.stdscr.get_wch()
+            except curses.error:  # pragma: no cover (macos bug?)
+                wch = self.stdscr.get_wch()
         if isinstance(wch, str) and wch == '\x1b':
             wch = self._get_sequence(wch)
             if len(wch) == 2:
@@ -259,9 +270,9 @@ class Screen:
     def quick_prompt(
             self,
             prompt: str,
-            opt_strs: Tuple[str, ...],
-    ) -> Union[str, PromptResult]:
-        opts = [opt[0] for opt in opt_strs]
+            opt_strs: tuple[str, ...],
+    ) -> str | PromptResult:
+        opts = {opt[0] for opt in opt_strs}
         while True:
             x = 0
             prompt_line = self.margin.lines - 1
@@ -298,18 +309,18 @@ class Screen:
                 self.resize()
             elif key.keyname == b'^C':
                 return self.status.cancelled()
-            elif isinstance(key.wch, str) and key.wch in opts:
-                return key.wch
+            elif isinstance(key.wch, str) and key.wch.lower() in opts:
+                return key.wch.lower()
 
     def prompt(
             self,
             prompt: str,
             *,
             allow_empty: bool = False,
-            history: Optional[str] = None,
+            history: str | None = None,
             default_prev: bool = False,
-            default: Optional[str] = None,
-    ) -> Union[str, PromptResult]:
+            default: str | None = None,
+    ) -> str | PromptResult:
         default = default or ''
         self.status.clear()
         if history is not None:
@@ -366,7 +377,7 @@ class Screen:
         else:
             self.file.uncut(self.cut_buffer, self.margin)
 
-    def _get_search_re(self, prompt: str) -> Union[Pattern[str], PromptResult]:
+    def _get_search_re(self, prompt: str) -> Pattern[str] | PromptResult:
         response = self.prompt(prompt, history='search', default_prev=True)
         if response is PromptResult.CANCELLED:
             return response
@@ -379,8 +390,8 @@ class Screen:
     def _undo_redo(
             self,
             op: str,
-            from_stack: List[Action],
-            to_stack: List[Action],
+            from_stack: list[Action],
+            to_stack: list[Action],
     ) -> None:
         if not from_stack:
             self.status.update(f'nothing to {op}!')
@@ -409,11 +420,18 @@ class Screen:
                 'replace with', history='replace', allow_empty=True,
             )
             if response is not PromptResult.CANCELLED:
-                self.file.replace(self, search_response, response)
+                try:
+                    sre_parse.parse_template(response, search_response)
+                except re.error:
+                    self.status.update('invalid replacement string')
+                else:
+                    self.file.replace(self, search_response, response)
 
-    def command(self) -> Optional[EditResult]:
+    def command(self) -> EditResult | None:
         response = self.prompt('', history='command')
-        if response == ':q':
+        if response is PromptResult.CANCELLED:
+            pass
+        elif response == ':q':
             return self.quit_save_modified()
         elif response == ':q!':
             return EditResult.EXIT
@@ -428,11 +446,45 @@ class Screen:
             else:
                 self.file.sort(self.margin)
             self.status.update('sorted!')
-        elif response is not PromptResult.CANCELLED:
+        elif response == ':sort!':
+            if self.file.selection.start:
+                self.file.sort_selection(self.margin, reverse=True)
+            else:
+                self.file.sort(self.margin, reverse=True)
+            self.status.update('sorted!')
+        elif response.startswith((':tabstop ', ':tabsize ')):
+            _, _, tab_size = response.partition(' ')
+            try:
+                parsed_tab_size = int(tab_size)
+            except ValueError:
+                self.status.update(f'invalid size: {tab_size}')
+            else:
+                if parsed_tab_size <= 0:
+                    self.status.update(f'invalid size: {parsed_tab_size}')
+                else:
+                    for file in self.files:
+                        file.buf.set_tab_size(parsed_tab_size)
+                    self.status.update('updated!')
+        elif response.startswith(':expandtabs'):
+            for file in self.files:
+                file.buf.expandtabs = True
+            self.status.update('updated!')
+        elif response.startswith(':noexpandtabs'):
+            for file in self.files:
+                file.buf.expandtabs = False
+            self.status.update('updated!')
+        elif response == ':comment' or response.startswith(':comment '):
+            _, _, comment = response.partition(' ')
+            comment = (comment or '#').strip()
+            if self.file.selection.start:
+                self.file.toggle_comment_selection(comment)
+            else:
+                self.file.toggle_comment(comment)
+        else:
             self.status.update(f'invalid command: {response}')
         return None
 
-    def save(self) -> Optional[PromptResult]:
+    def save(self) -> PromptResult | None:
         self.file.finalize_previous_action()
 
         # TODO: make directories if they don't exist
@@ -446,22 +498,28 @@ class Screen:
             else:
                 self.file.filename = filename
 
-        if os.path.isfile(self.file.filename):
-            with open(self.file.filename, newline='') as f:
-                *_, sha256 = get_lines(f)
+        if not os.path.isfile(self.file.filename):
+            sha256: str | None = None
         else:
-            sha256 = hashlib.sha256(b'').hexdigest()
+            with open(self.file.filename, encoding='UTF-8', newline='') as f:
+                *_, sha256 = get_lines(f)
 
         contents = self.file.nl.join(self.file.buf)
         sha256_to_save = hashlib.sha256(contents.encode()).hexdigest()
 
         # the file on disk is the same as when we opened it
-        if sha256 not in (self.file.sha256, sha256_to_save):
+        if sha256 not in (None, self.file.sha256, sha256_to_save):
             self.status.update('(file changed on disk, not implemented)')
             return PromptResult.CANCELLED
 
-        with open(self.file.filename, 'w', newline='') as f:
-            f.write(contents)
+        try:
+            with open(
+                self.file.filename, 'w', encoding='UTF-8', newline='',
+            ) as f:
+                f.write(contents)
+        except OSError as e:
+            self.status.update(f'cannot save file: {e}')
+            return PromptResult.CANCELLED
 
         self.file.modified = False
         self.file.sha256 = sha256_to_save
@@ -478,7 +536,7 @@ class Screen:
                 first = False
         return None
 
-    def save_filename(self) -> Optional[PromptResult]:
+    def save_filename(self) -> PromptResult | None:
         response = self.prompt('enter filename', default=self.file.filename)
         if response is PromptResult.CANCELLED:
             return PromptResult.CANCELLED
@@ -486,16 +544,16 @@ class Screen:
             self.file.filename = response
             return self.save()
 
-    def open_file(self) -> Optional[EditResult]:
+    def open_file(self) -> EditResult | None:
         response = self.prompt('enter filename', history='open')
         if response is not PromptResult.CANCELLED:
-            opened = File(response, self.color_manager, self.hl_factories)
+            opened = File(response, 0, self.color_manager, self.hl_factories)
             self.files.append(opened)
             return EditResult.OPEN
         else:
             return None
 
-    def quit_save_modified(self) -> Optional[EditResult]:
+    def quit_save_modified(self) -> EditResult | None:
         if self.file.modified:
             response = self.quick_prompt(
                 'file is modified - save', ('yes', 'no'),
@@ -513,10 +571,13 @@ class Screen:
         return EditResult.EXIT
 
     def background(self) -> None:
-        curses.endwin()
-        os.kill(os.getpid(), signal.SIGSTOP)
-        self.stdscr = _init_screen()
-        self.resize()
+        if sys.platform == 'win32':  # pragma: win32 cover
+            self.status.update('cannot run babi in background on Windows')
+        else:  # pragma: win32 no cover
+            curses.endwin()
+            os.kill(os.getpid(), signal.SIGSTOP)
+            self.stdscr = _init_screen()
+            self.resize()
 
     DISPATCH = {
         b'KEY_RESIZE': resize,
@@ -526,6 +587,7 @@ class Screen:
         b'^U': uncut,
         b'M-u': undo,
         b'M-U': redo,
+        b'M-e': redo,
         b'^W': search,
         b'^\\': replace,
         b'^[': command,
@@ -539,9 +601,12 @@ class Screen:
     }
 
 
-def _init_screen() -> 'curses._CursesWindow':
+def _init_screen() -> curses._CursesWindow:
     # set the escape delay so curses does not pause waiting for sequences
-    if sys.version_info >= (3, 9):  # pragma: no cover
+    if (
+            sys.version_info >= (3, 9) and
+            hasattr(curses, 'set_escdelay')
+    ):  # pragma: no cover
         curses.set_escdelay(25)
     else:  # pragma: no cover
         os.environ.setdefault('ESCDELAY', '25')
@@ -562,7 +627,7 @@ def _init_screen() -> 'curses._CursesWindow':
 
 
 @contextlib.contextmanager
-def make_stdscr() -> Generator['curses._CursesWindow', None, None]:
+def make_stdscr() -> Generator[curses._CursesWindow, None, None]:
     """essentially `curses.wrapper` but split out to implement ^Z"""
     try:
         yield _init_screen()

babi/status.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import curses
 
 from babi.margin import Margin
@@ -16,7 +18,7 @@ class Status:
     def clear(self) -> None:
         self._status = ''
 
-    def draw(self, stdscr: 'curses._CursesWindow', margin: Margin) -> None:
+    def draw(self, stdscr: curses._CursesWindow, margin: Margin) -> None:
         if margin.footer or self._status:
             stdscr.insstr(margin.lines - 1, 0, ' ' * margin.cols)
             if self._status:

babi/textmate_demo.py

@@ -1,5 +1,6 @@
+from __future__ import annotations
+
 import argparse
-from typing import Optional
 from typing import Sequence
 
 from babi.highlight import Compiler
@@ -37,7 +38,7 @@ def _highlight_output(theme: Theme, compiler: Compiler, filename: str) -> int:
 
     if theme.default.bg is not None:
         print('\x1b[48;2;{r};{g};{b}m'.format(**theme.default.bg._asdict()))
-    with open(filename) as f:
+    with open(filename, encoding='UTF-8') as f:
         for line_idx, line in enumerate(f):
             first_line = line_idx == 0
             state, regions = highlight_line(compiler, state, line, first_line)
@@ -47,14 +48,14 @@ def _highlight_output(theme: Theme, compiler: Compiler, filename: str) -> int:
     return 0
 
 
-def main(argv: Optional[Sequence[str]] = None) -> int:
+def main(argv: Sequence[str] | None = None) -> int:
     parser = argparse.ArgumentParser()
     parser.add_argument('--theme', default=xdg_config('theme.json'))
     parser.add_argument('--grammar-dir', default=prefix_data('grammar_v1'))
     parser.add_argument('filename')
     args = parser.parse_args(argv)
 
-    with open(args.filename) as f:
+    with open(args.filename, encoding='UTF-8') as f:
         first_line = next(f, '')
 
     theme = Theme.from_filename(args.theme)
@@ -66,4 +67,4 @@ def main(argv: Optional[Sequence[str]] = None) -> int:
 
 
 if __name__ == '__main__':
-    exit(main())
+    raise SystemExit(main())

babi/theme.py

@@ -1,11 +1,10 @@
+from __future__ import annotations
+
 import functools
 import json
 import os.path
 from typing import Any
-from typing import Dict
 from typing import NamedTuple
-from typing import Optional
-from typing import Tuple
 
 from babi._types import Protocol
 from babi.color import Color
@@ -13,32 +12,32 @@ from babi.fdict import FDict
 
 
 class Style(NamedTuple):
-    fg: Optional[Color]
-    bg: Optional[Color]
+    fg: Color | None
+    bg: Color | None
     b: bool
     i: bool
     u: bool
 
     @classmethod
-    def blank(cls) -> 'Style':
+    def blank(cls) -> Style:
         return cls(fg=None, bg=None, b=False, i=False, u=False)
 
 
 class PartialStyle(NamedTuple):
-    fg: Optional[Color] = None
-    bg: Optional[Color] = None
-    b: Optional[bool] = None
-    i: Optional[bool] = None
-    u: Optional[bool] = None
+    fg: Color | None = None
+    bg: Color | None = None
+    b: bool | None = None
+    i: bool | None = None
+    u: bool | None = None
 
-    def overlay_on(self, dct: Dict[str, Any]) -> None:
+    def overlay_on(self, dct: dict[str, Any]) -> None:
         for attr in self._fields:
             value = getattr(self, attr)
             if value is not None:
                 dct[attr] = value
 
     @classmethod
-    def from_dct(cls, dct: Dict[str, Any]) -> 'PartialStyle':
+    def from_dct(cls, dct: dict[str, Any]) -> PartialStyle:
         kv = cls()._asdict()
         if 'foreground' in dct:
             kv['fg'] = Color.parse(dct['foreground'])
@@ -57,7 +56,7 @@ class _TrieNode(Protocol):
     @property
     def style(self) -> PartialStyle: ...
     @property
-    def children(self) -> FDict[str, '_TrieNode']: ...
+    def children(self) -> FDict[str, _TrieNode]: ...
 
 
 class TrieNode(NamedTuple):
@@ -65,7 +64,7 @@ class TrieNode(NamedTuple):
     children: FDict[str, _TrieNode]
 
     @classmethod
-    def from_dct(cls, dct: Dict[str, Any]) -> _TrieNode:
+    def from_dct(cls, dct: dict[str, Any]) -> _TrieNode:
         children = FDict({
             k: TrieNode.from_dct(v) for k, v in dct['children'].items()
         })
@@ -77,7 +76,7 @@ class Theme(NamedTuple):
     rules: _TrieNode
 
     @functools.lru_cache(maxsize=None)
-    def select(self, scope: Tuple[str, ...]) -> Style:
+    def select(self, scope: tuple[str, ...]) -> Style:
         if not scope:
             return self.default
         else:
@@ -92,7 +91,7 @@ class Theme(NamedTuple):
             return Style(**style)
 
     @classmethod
-    def from_dct(cls, data: Dict[str, Any]) -> 'Theme':
+    def from_dct(cls, data: dict[str, Any]) -> Theme:
         default = Style.blank()._asdict()
 
         for k in ('foreground', 'editor.foreground'):
@@ -105,7 +104,7 @@ class Theme(NamedTuple):
                 default['bg'] = Color.parse(data['colors'][k])
                 break
 
-        root: Dict[str, Any] = {'children': {}}
+        root: dict[str, Any] = {'children': {}}
         rules = data.get('tokenColors', []) + data.get('settings', [])
         for rule in rules:
             if 'scope' not in rule:
@@ -139,13 +138,13 @@ class Theme(NamedTuple):
         return cls(Style(**default), TrieNode.from_dct(root))
 
     @classmethod
-    def blank(cls) -> 'Theme':
+    def blank(cls) -> Theme:
         return cls(Style.blank(), TrieNode.from_dct({'children': {}}))
 
     @classmethod
-    def from_filename(cls, filename: str) -> 'Theme':
+    def from_filename(cls, filename: str) -> Theme:
         if not os.path.exists(filename):
             return cls.blank()
         else:
-            with open(filename) as f:
+            with open(filename, encoding='UTF-8') as f:
                 return cls.from_dct(json.load(f))

babi/user_data.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import os.path
 import sys
 

bin/download-theme

@@ -1,4 +1,6 @@
 #!/usr/bin/env python3
+from __future__ import annotations
+
 import argparse
 import io
 import json

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = babi
-version = 0.0.7
+version = 0.0.24
 description = a text editor
 long_description = file: README.md
 long_description_content_type = text/markdown
@@ -13,9 +13,10 @@ classifiers =
     License :: OSI Approved :: MIT License
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3 :: Only
-    Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
+    Programming Language :: Python :: 3.9
+    Programming Language :: Python :: 3.10
     Programming Language :: Python :: Implementation :: CPython
     Programming Language :: Python :: Implementation :: PyPy
 
@@ -24,21 +25,21 @@ packages = find:
 install_requires =
     babi-grammars
     identify
-    onigurumacffi>=0.0.10
+    onigurumacffi>=0.0.18
     importlib_metadata>=1;python_version<"3.8"
     windows-curses;sys_platform=="win32"
-python_requires = >=3.6.1
-
-[options.entry_points]
-console_scripts =
-    babi = babi.main:main
-    babi-textmate-demo = babi.textmate_demo:main
+python_requires = >=3.7
 
 [options.packages.find]
 exclude =
     tests*
     testing*
 
+[options.entry_points]
+console_scripts =
+    babi = babi.main:main
+    babi-textmate-demo = babi.textmate_demo:main
+
 [bdist_wheel]
 universal = True
 
@@ -52,6 +53,8 @@ disallow_any_generics = true
 disallow_incomplete_defs = true
 disallow_untyped_defs = true
 no_implicit_optional = true
+warn_redundant_casts = true
+warn_unused_ignores = true
 
 [mypy-testing.*]
 disallow_untyped_defs = false

setup.py

@@ -1,2 +1,4 @@
+from __future__ import annotations
+
 from setuptools import setup
 setup()

testing/runner.py

@@ -1,9 +1,9 @@
+from __future__ import annotations
+
 import contextlib
 import curses
 import enum
 import re
-from typing import List
-from typing import Tuple
 
 from hecate import Runner
 
@@ -34,7 +34,7 @@ def to_attrs(screen, width):
     fg = bg = -1
     attr = 0
     idx = 0
-    ret: List[List[Tuple[int, int, int]]]
+    ret: list[list[tuple[int, int, int]]]
     ret = [[] for _ in range(len(screen.splitlines()))]
 
     for tp, match in tokenize_colors(screen):

tests/buf_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from babi.buf import Buf

tests/color_kd_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from babi import color_kd
 from babi.color import Color
 

tests/color_manager_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from babi.color import Color

tests/color_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from babi.color import Color

tests/conftest.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import json
 
 import pytest

tests/fdict_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from babi.fdict import FChainMap

tests/features/command_mode_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from testing.runner import and_exit

tests/features/comment_test.py

@@ -0,0 +1,207 @@
+from __future__ import annotations
+
+import pytest
+
+from testing.runner import and_exit
+from testing.runner import trigger_command_mode
+
+
+@pytest.fixture
+def three_lines_with_indentation(tmpdir):
+    f = tmpdir.join('f')
+    f.write('line_0\n    line_1\n    line_2')
+    return f
+
+
+def test_comment_some_code(run, ten_lines):
+    with run(str(ten_lines)) as h, and_exit(h):
+        h.press('S-Down')
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_text('# line_0\n# line_1\nline_2\n')
+
+
+def test_comment_empty_line_trailing_whitespace(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('1\n\n2\n')
+
+    with run(str(f)) as h, and_exit(h):
+        h.press('S-Down')
+        h.press('S-Down')
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_text('# 1\n#\n# 2')
+
+
+def test_comment_some_code_with_alternate_comment_character(run, ten_lines):
+    with run(str(ten_lines)) as h, and_exit(h):
+        h.press('S-Down')
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment //')
+
+        h.await_text('// line_0\n// line_1\nline_2\n')
+
+
+def test_comment_partially_commented(run, ten_lines):
+    with run(str(ten_lines)) as h, and_exit(h):
+        h.press('#')
+        h.press('S-Down')
+        h.await_text('#line_0\nline_1\nline_2')
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_text('line_0\nline_1\nline_2\n')
+
+
+def test_comment_partially_uncommented(run, ten_lines):
+    with run(str(ten_lines)) as h, and_exit(h):
+        h.press('Down')
+        h.press('#')
+        h.press('Up')
+        h.press('S-Down')
+        h.await_text('line_0\n#line_1\nline_2')
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_text('# line_0\n# #line_1\nline_2\n')
+
+
+def test_comment_single_line(run, ten_lines):
+    with run(str(ten_lines)) as h, and_exit(h):
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_text('# line_0\nline_1\n')
+
+
+def test_uncomment_single_line(run, ten_lines):
+    with run(str(ten_lines)) as h, and_exit(h):
+        h.press('#')
+        h.await_text('#line_0\nline_1\n')
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_text('line_0\nline_1\n')
+
+
+def test_comment_with_trailing_whitespace(run, ten_lines):
+    with run(str(ten_lines)) as h, and_exit(h):
+        trigger_command_mode(h)
+        h.press_and_enter(':comment //   ')
+
+        h.await_text('// line_0\nline_1\n')
+
+
+def test_comment_some_code_with_indentation(run, three_lines_with_indentation):
+    with run(str(three_lines_with_indentation)) as h, and_exit(h):
+        h.press('S-Down')
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_text('# line_0\n#     line_1\n    line_2\n')
+
+        h.press('S-Up')
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_text('line_0\n    line_1\n    line_2\n')
+
+
+def test_comment_some_code_on_indent_part(run, three_lines_with_indentation):
+    with run(str(three_lines_with_indentation)) as h, and_exit(h):
+        h.press('Down')
+        h.press('S-Down')
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_text('line_0\n    # line_1\n    # line_2\n')
+
+        h.press('S-Up')
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_text('line_0\n    line_1\n    line_2\n')
+
+
+def test_comment_some_code_on_tabs_part(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('line_0\n\tline_1\n\t\tline_2')
+
+    with run(str(f)) as h, and_exit(h):
+        h.await_text('line_0\n    line_1\n        line_2')
+        h.press('Down')
+        h.press('S-Down')
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_text('line_0\n    # line_1\n    #   line_2')
+
+        h.press('S-Up')
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_text('line_0\n    line_1\n        line_2')
+
+
+def test_comment_cursor_at_end_of_line(run, ten_lines):
+    with run(str(ten_lines)) as h, and_exit(h):
+        h.press('# ')
+        h.press('End')
+        h.await_cursor_position(x=8, y=1)
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_cursor_position(x=6, y=1)
+
+
+def test_add_comment_moves_cursor(run, ten_lines):
+    with run(str(ten_lines)) as h, and_exit(h):
+        h.press('End')
+
+        h.await_cursor_position(x=6, y=1)
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_cursor_position(x=8, y=1)
+
+
+def test_do_not_move_if_cursor_before_comment(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('\t\tfoo')
+
+    with run(str(f)) as h, and_exit(h):
+        h.press('Right')
+
+        h.await_cursor_position(x=4, y=1)
+
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_cursor_position(x=4, y=1)
+
+
+@pytest.mark.parametrize('comment', ('# ', '#'))
+def test_remove_comment_with_comment_elsewhere_in_line(run, tmpdir, comment):
+    f = tmpdir.join('f')
+    f.write(f'{comment}print("not a # comment here!")\n')
+
+    with run(str(f)) as h, and_exit(h):
+        trigger_command_mode(h)
+        h.press_and_enter(':comment')
+
+        h.await_text('\nprint("not a # comment here!")\n')

tests/features/conftest.py

@@ -1,11 +1,10 @@
+from __future__ import annotations
+
 import contextlib
 import curses
 import os
 import sys
-from typing import List
 from typing import NamedTuple
-from typing import Tuple
-from typing import Union
 from unittest import mock
 
 import pytest
@@ -148,7 +147,7 @@ class AssertScreenLineEquals(NamedTuple):
 
 class AssertScreenAttrEquals(NamedTuple):
     n: int
-    attr: List[Tuple[int, int, int]]
+    attr: list[tuple[int, int, int]]
 
     def __call__(self, screen: Screen) -> None:
         assert screen.attrs[self.n] == self.attr
@@ -170,7 +169,7 @@ class Resize(NamedTuple):
 
 
 class KeyPress(NamedTuple):
-    wch: Union[int, str]
+    wch: int | str
 
     def __call__(self, screen: Screen) -> None:
         raise AssertionError('unreachable')
@@ -236,7 +235,7 @@ class CursesScreen:
 class Key(NamedTuple):
     tmux: str
     curses: bytes
-    wch: Union[int, str]
+    wch: int | str
 
     @property
     def value(self) -> int:
@@ -290,6 +289,7 @@ KEYS = [
     Key('^_', b'^_', '\x1f'),
     Key('^\\', b'^\\', '\x1c'),
     Key('!resize', b'KEY_RESIZE', curses.KEY_RESIZE),
+    Key('^D', b'^D', '\x04'),
 ]
 KEYS_TMUX = {k.tmux: k.wch for k in KEYS}
 KEYS_CURSES = {k.value: k.curses for k in KEYS}
@@ -299,10 +299,11 @@ class DeferredRunner:
     def __init__(self, command, width=80, height=24, term='screen'):
         self.command = command
         self._i = 0
-        self._ops: List[Op] = []
+        self._ops: list[Op] = []
         self.color_pairs = {0: (7, 0)}
         self.screen = Screen(width, height)
         self._n_colors, self._can_change_color = {
+            'xterm-mono': (0, False),
             'screen': (8, False),
             'screen-256color': (256, False),
             'xterm-256color': (256, True),
@@ -391,6 +392,7 @@ class DeferredRunner:
 
     _curses_cbreak = _curses_endwin = _curses_noecho = _curses__noop
     _curses_nonl = _curses_raw = _curses_use_default_colors = _curses__noop
+    _curses_set_escdelay = _curses__noop
 
     _curses_error = curses.error  # so we don't mock the exception
 

tests/features/current_position_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from testing.runner import and_exit
 
 

tests/features/cut_uncut_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from testing.runner import and_exit
 
 

tests/features/expandtabs_test.py

@@ -0,0 +1,47 @@
+from __future__ import annotations
+
+from testing.runner import and_exit
+from testing.runner import trigger_command_mode
+
+
+def test_set_expandtabs(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('a')
+
+    with run(str(f)) as h, and_exit(h):
+        h.press('Left')
+        trigger_command_mode(h)
+        h.press_and_enter(':expandtabs')
+        h.await_text('updated!')
+        h.press('Tab')
+        h.press('^S')
+    assert f.read() == '    a\n'
+
+
+def test_set_noexpandtabs(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('a')
+
+    with run(str(f)) as h, and_exit(h):
+        h.press('Left')
+        trigger_command_mode(h)
+        h.press_and_enter(':noexpandtabs')
+        h.await_text('updated!')
+        h.press('Tab')
+        h.press('^S')
+    assert f.read() == '\ta\n'
+
+
+def test_indent_with_expandtabs(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('a\nb\nc')
+
+    with run(str(f)) as h, and_exit(h):
+        trigger_command_mode(h)
+        h.press_and_enter(':noexpandtabs')
+        h.await_text('updated!')
+        for _ in range(3):
+            h.press('S-Down')
+        h.press('Tab')
+        h.press('^S')
+    assert f.read() == '\ta\n\tb\n\tc\n'

tests/features/go_to_line_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from testing.runner import and_exit

tests/features/indent_test.py

@@ -1,4 +1,7 @@
+from __future__ import annotations
+
 from testing.runner import and_exit
+from testing.runner import trigger_command_mode
 
 
 def test_indent_at_beginning_of_line(run):
@@ -12,11 +15,12 @@ def test_indent_at_beginning_of_line(run):
 
 def test_indent_not_full_tab(run):
     with run() as h, and_exit(h):
-        h.press('h')
+        h.press('hello')
+        h.press('Home')
+        h.press('Right')
         h.press('Tab')
-        h.press('ello')
         h.await_text('h   ello')
-        h.await_cursor_position(x=8, y=1)
+        h.await_cursor_position(x=4, y=1)
 
 
 def test_indent_fixes_eof(run):
@@ -86,6 +90,20 @@ def test_dedent_selection(run, tmpdir):
         h.await_text('\n1\n2\n    3\n')
 
 
+def test_dedent_selection_with_noexpandtabs(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('1\n\t2\n\t\t3\n')
+    with run(str(f)) as h, and_exit(h):
+        trigger_command_mode(h)
+        h.press_and_enter(':noexpandtabs')
+        h.await_text('updated!')
+        for _ in range(3):
+            h.press('S-Down')
+        h.press('BTab')
+        h.press('^S')
+    assert f.read() == '1\n2\n\t3\n'
+
+
 def test_dedent_beginning_of_line(run, tmpdir):
     f = tmpdir.join('f')
     f.write('    hi\n')

tests/features/initial_position_test.py

@@ -0,0 +1,30 @@
+from __future__ import annotations
+
+from testing.runner import and_exit
+
+
+def test_open_file_named_plus_something(run):
+    with run('+3') as h, and_exit(h):
+        h.await_text(' +3')
+
+
+def test_initial_position_one_file(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('hello\nworld\n')
+
+    with run('+2', str(f)) as h, and_exit(h):
+        h.await_cursor_position(x=0, y=2)
+
+
+def test_initial_position_multiple_files(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('1\n2\n3\n4\n')
+    g = tmpdir.join('g')
+    g.write('5\n6\n7\n8\n')
+
+    with run('+2', str(f), '+3', str(g)) as h, and_exit(h):
+        h.await_cursor_position(x=0, y=2)
+
+        h.press('^X')
+
+        h.await_cursor_position(x=0, y=3)

tests/features/key_debug_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import curses
 
 from babi.screen import VERSION_STR

tests/features/movement_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from testing.runner import and_exit

tests/features/multiple_files_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 

tests/features/open_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from testing.runner import and_exit
 
 

tests/features/perf_log_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from testing.runner import and_exit
 
 

tests/features/replace_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from testing.runner import and_exit
@@ -20,6 +22,16 @@ def test_replace_invalid_regex(run):
         h.await_text("invalid regex: '('")
 
 
+def test_replace_invalid_replacement(run, ten_lines):
+    with run(str(ten_lines)) as h, and_exit(h):
+        h.press('^\\')
+        h.await_text('search (to replace):')
+        h.press_and_enter('line_0')
+        h.await_text('replace with:')
+        h.press_and_enter('\\')
+        h.await_text('invalid replacement string')
+
+
 def test_replace_cancel_at_replace_string(run):
     with run() as h, and_exit(h):
         h.press('^\\')
@@ -30,7 +42,8 @@ def test_replace_cancel_at_replace_string(run):
         h.await_text('cancelled')
 
 
-def test_replace_actual_contents(run, ten_lines):
+@pytest.mark.parametrize('key', ('y', 'Y'))
+def test_replace_actual_contents(run, ten_lines, key):
     with run(str(ten_lines)) as h, and_exit(h):
         h.press('^\\')
         h.await_text('search (to replace):')
@@ -38,7 +51,7 @@ def test_replace_actual_contents(run, ten_lines):
         h.await_text('replace with:')
         h.press_and_enter('ohai')
         h.await_text('replace [yes, no, all]?')
-        h.press('y')
+        h.press(key)
         h.await_text_missing('line_0')
         h.await_text('ohai')
         h.await_text(' *')

tests/features/resize_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from babi.screen import VERSION_STR
 from testing.runner import and_exit
 

tests/features/save_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from testing.runner import and_exit
@@ -128,12 +130,24 @@ def test_save_file_when_it_did_not_exist(run, tmpdir):
     assert f.read() == 'hello world\n'
 
 
+def test_saving_file_permission_denied(run, tmpdir):
+    f = tmpdir.join('f').ensure()
+    f.chmod(0o400)
+
+    with run(str(f)) as h, and_exit(h):
+        h.press('hello world')
+        h.press('^S')
+        # the filename message is missing as it is too long to be captured
+        h.await_text('cannot save file: [Errno 13] Permission denied:')
+        h.await_text(' *')
+
+
 def test_save_via_ctrl_o(run, tmpdir):
     f = tmpdir.join('f')
     with run(str(f)) as h, and_exit(h):
         h.press('hello world')
         h.press('^O')
-        h.await_text(f'enter filename: ')
+        h.await_text('enter filename: ')
         h.press('Enter')
         h.await_text('saved! (1 line written)')
     assert f.read() == 'hello world\n'
@@ -150,6 +164,18 @@ def test_save_via_ctrl_o_set_filename(run, tmpdir):
     assert f.read() == 'hello world\n'
 
 
+def test_save_via_ctrl_o_new_filename(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('wat\n')
+    with run(str(f)) as h, and_exit(h):
+        h.press('^O')
+        h.await_text('enter filename: ')
+        h.press_and_enter('new')
+        h.await_text('saved! (1 line written)')
+    assert f.read() == 'wat\n'
+    assert tmpdir.join('fnew').read() == 'wat\n'
+
+
 @pytest.mark.parametrize('key', ('^C', 'Enter'))
 def test_save_via_ctrl_o_cancelled(run, key):
     with run() as h, and_exit(h):
@@ -237,7 +263,7 @@ def test_vim_save_on_exit(run, tmpdir):
         h.press_and_enter(':q')
         h.await_text('file is modified - save [yes, no]?')
         h.press('y')
-        h.await_text(f'enter filename: ')
+        h.await_text('enter filename: ')
         h.press('Enter')
         h.await_exit()
 

tests/features/search_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from testing.runner import and_exit

tests/features/sort_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from testing.runner import and_exit
@@ -21,6 +23,16 @@ def test_sort_entire_file(run, unsorted):
     assert unsorted.read() == 'a\nb\nc\nd\n'
 
 
+def test_reverse_sort_entire_file(run, unsorted):
+    with run(str(unsorted)) as h, and_exit(h):
+        trigger_command_mode(h)
+        h.press_and_enter(':sort!')
+        h.await_text('sorted!')
+        h.await_cursor_position(x=0, y=1)
+        h.press('^S')
+    assert unsorted.read() == 'd\nc\nb\na\n'
+
+
 def test_sort_selection(run, unsorted):
     with run(str(unsorted)) as h, and_exit(h):
         h.press('S-Down')
@@ -32,6 +44,18 @@ def test_sort_selection(run, unsorted):
     assert unsorted.read() == 'b\nd\nc\na\n'
 
 
+def test_reverse_sort_selection(run, unsorted):
+    with run(str(unsorted)) as h, and_exit(h):
+        h.press('Down')
+        h.press('S-Down')
+        trigger_command_mode(h)
+        h.press_and_enter(':sort!')
+        h.await_text('sorted!')
+        h.await_cursor_position(x=0, y=2)
+        h.press('^S')
+    assert unsorted.read() == 'd\nc\nb\na\n'
+
+
 def test_sort_selection_does_not_include_eof(run, unsorted):
     with run(str(unsorted)) as h, and_exit(h):
         for _ in range(5):

tests/features/status_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from testing.runner import and_exit
 
 

tests/features/stdin_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import shlex
 import sys
 

tests/features/suspend_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import shlex
 import sys
 

tests/features/syntax_highlight_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import curses
 import json
 
@@ -153,3 +155,8 @@ def test_syntax_highlighting_tabs_after_line_creation(run, tmpdir):
         h.press('Enter')
 
         h.await_text('foo\n    x\nx\ny\n')
+
+
+def test_does_not_crash_with_no_color_support(run):
+    with run(term='xterm-mono') as h, and_exit(h):
+        pass

tests/features/tabsize_test.py

@@ -0,0 +1,32 @@
+from __future__ import annotations
+
+import pytest
+
+from testing.runner import and_exit
+from testing.runner import trigger_command_mode
+
+
+@pytest.mark.parametrize('setting', ('tabsize', 'tabstop'))
+def test_set_tabstop(run, setting):
+    with run() as h, and_exit(h):
+        h.press('a')
+        h.press('Left')
+        trigger_command_mode(h)
+        h.press_and_enter(f':{setting} 2')
+        h.await_text('updated!')
+        h.press('Tab')
+        h.await_text('\n  a')
+        h.await_cursor_position(x=2, y=1)
+
+
+@pytest.mark.parametrize('tabsize', ('-1', '0', 'wat'))
+def test_set_invalid_tabstop(run, tabsize):
+    with run() as h, and_exit(h):
+        h.press('a')
+        h.press('Left')
+        trigger_command_mode(h)
+        h.press_and_enter(f':tabstop {tabsize}')
+        h.await_text(f'invalid size: {tabsize}')
+        h.press('Tab')
+        h.await_text('    a')
+        h.await_cursor_position(x=4, y=1)

tests/features/text_editing_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from testing.runner import and_exit
@@ -50,6 +52,18 @@ def test_backspace_at_end_of_file_still_allows_scrolling_down(run, tmpdir):
         h.await_text_missing('*')
 
 
+def test_backspace_deletes_newline_at_end_of_file(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('foo\n\n')
+
+    with run(str(f)) as h, and_exit(h):
+        h.press('^End')
+        h.press('BSpace')
+        h.press('^S')
+
+    assert f.read() == 'foo\n'
+
+
 @pytest.mark.parametrize('key', ('BSpace', '^H'))
 def test_backspace_deletes_text(run, tmpdir, key):
     f = tmpdir.join('f')
@@ -72,14 +86,15 @@ def test_delete_at_end_of_file(run, tmpdir):
         h.await_text_missing('*')
 
 
-def test_delete_removes_character_afterwards(run, tmpdir):
+@pytest.mark.parametrize('key', ('DC', '^D'))
+def test_delete_removes_character_afterwards(run, tmpdir, key):
     f = tmpdir.join('f')
     f.write('hello world')
 
     with run(str(f)) as h, and_exit(h):
         h.await_text('hello world')
         h.press('Right')
-        h.press('DC')
+        h.press(key)
         h.await_text('hllo world')
         h.await_text('f *')
 

tests/features/trailing_whitespace_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import curses
 
 from testing.runner import and_exit

tests/features/undo_redo_test.py

@@ -1,3 +1,7 @@
+from __future__ import annotations
+
+import pytest
+
 from testing.runner import and_exit
 
 
@@ -9,7 +13,8 @@ def test_nothing_to_undo_redo(run):
         h.await_text('nothing to redo!')
 
 
-def test_undo_redo(run):
+@pytest.mark.parametrize('r', ('M-U', 'M-e'))
+def test_undo_redo(run, r):
     with run() as h, and_exit(h):
         h.press('hello')
         h.await_text('hello')
@@ -17,7 +22,7 @@ def test_undo_redo(run):
         h.await_text('undo: text')
         h.await_text_missing('hello')
         h.await_text_missing(' *')
-        h.press('M-U')
+        h.press(r)
         h.await_text('redo: text')
         h.await_text('hello')
         h.await_text(' *')

tests/file_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import io
 
 import pytest
@@ -8,7 +10,7 @@ from babi.file import get_lines
 
 
 def test_position_repr():
-    ret = repr(File('f.txt', ColorManager.make(), ()))
+    ret = repr(File('f.txt', 0, ColorManager.make(), ()))
     assert ret == "<File 'f.txt'>"
 
 

tests/highlight_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from babi.highlight import highlight_line
@@ -637,3 +639,25 @@ def test_backslash_z(compiler_state):
     assert regions2 == (
         Region(0, 6, ('test', 'comment')),
     )
+
+
+def test_buggy_begin_end_grammar(compiler_state):
+    # before this would result in an infinite loop of start / end
+    compiler, state = compiler_state({
+        'scopeName': 'test',
+        'patterns': [
+            {
+                'begin': '(?=</style)',
+                'end': '(?=</style)',
+                'name': 'css',
+            },
+        ],
+    })
+
+    state, regions = highlight_line(compiler, state, 'test </style', True)
+
+    assert regions == (
+        Region(0, 5, ('test',)),
+        Region(5, 6, ('test', 'css')),
+        Region(6, 12, ('test',)),
+    )

tests/hl/syntax_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import contextlib
 import curses
 from unittest import mock

tests/main_test.py

@@ -0,0 +1,21 @@
+from __future__ import annotations
+
+import pytest
+
+from babi import main
+
+
+@pytest.mark.parametrize(
+    ('in_filenames', 'expected_filenames', 'expected_positions'),
+    (
+        ([], [None], [0]),
+        (['+3'], ['+3'], [0]),
+        (['f'], ['f'], [0]),
+        (['+3', 'f'], ['f'], [3]),
+        (['+-3', 'f'], ['f'], [-3]),
+        (['+3', '+3'], ['+3'], [3]),
+        (['+2', 'f', '+5', 'g'], ['f', 'g'], [2, 5]),
+    ),
+)
+def test_filenames(in_filenames, expected_filenames, expected_positions):
+    filenames, positions = main._filenames(in_filenames)

tests/reg_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import onigurumacffi
 import pytest
 
@@ -35,9 +37,8 @@ def test_reg_other_escapes_left_untouched():
 def test_reg_not_out_of_bounds_at_end():
     # the only way this is triggerable is with an illegal regex, we'd rather
     # produce an error about the regex being wrong than an IndexError
-    reg = _Reg('\\A\\')
     with pytest.raises(onigurumacffi.OnigError) as excinfo:
-        reg.search('\\', 0, first_line=False, boundary=False)
+        _Reg('\\A\\')
     msg, = excinfo.value.args
     assert msg == 'end pattern at escape'
 

tests/textmate_demo_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import json
 
 import pytest

tests/theme_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import pytest
 
 from babi.color import Color

tests/user_data_test.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import os
 from unittest import mock
 

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py36,py37,pre-commit
+envlist = py37,pre-commit
 
 [testenv]
 deps = -rrequirements-dev.txt