--- a/contrib/grey.py Tue Oct 29 10:43:47 2019 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,4094 +0,0 @@
-# no-check-code because 3rd party
-import ast
-import asyncio
-from concurrent.futures import Executor, ProcessPoolExecutor
-from contextlib import contextmanager
-from datetime import datetime
-from enum import Enum
-from functools import lru_cache, partial, wraps
-import io
-import itertools
-import logging
-from multiprocessing import Manager, freeze_support
-import os
-from pathlib import Path
-import pickle
-import re
-import signal
-import sys
-import tempfile
-import tokenize
-import traceback
-from typing import (
- Any,
- Callable,
- Collection,
- Dict,
- Generator,
- Generic,
- Iterable,
- Iterator,
- List,
- Optional,
- Pattern,
- Sequence,
- Set,
- Tuple,
- TypeVar,
- Union,
- cast,
-)
-
-from appdirs import user_cache_dir
-from attr import dataclass, evolve, Factory
-import click
-import toml
-from typed_ast import ast3, ast27
-
-# lib2to3 fork
-from blib2to3.pytree import Node, Leaf, type_repr
-from blib2to3 import pygram, pytree
-from blib2to3.pgen2 import driver, token
-from blib2to3.pgen2.grammar import Grammar
-from blib2to3.pgen2.parse import ParseError
-
-__version__ = '19.3b1.dev95+gdc1add6.d20191005'
-
-DEFAULT_LINE_LENGTH = 88
-DEFAULT_EXCLUDES = (
- r"/(\.eggs|\.git|\.hg|\.mypy_cache|\.nox|\.tox|\.venv|_build|buck-out|build|dist)/"
-)
-DEFAULT_INCLUDES = r"\.pyi?$"
-CACHE_DIR = Path(user_cache_dir("black", version=__version__))
-
-
-# types
-FileContent = str
-Encoding = str
-NewLine = str
-Depth = int
-NodeType = int
-LeafID = int
-Priority = int
-Index = int
-LN = Union[Leaf, Node]
-SplitFunc = Callable[["Line", Collection["Feature"]], Iterator["Line"]]
-Timestamp = float
-FileSize = int
-CacheInfo = Tuple[Timestamp, FileSize]
-Cache = Dict[Path, CacheInfo]
-out = partial(click.secho, bold=True, err=True)
-err = partial(click.secho, fg="red", err=True)
-
-pygram.initialize(CACHE_DIR)
-syms = pygram.python_symbols
-
-
-class NothingChanged(UserWarning):
- """Raised when reformatted code is the same as source."""
-
-
-class CannotSplit(Exception):
- """A readable split that fits the allotted line length is impossible."""
-
-
-class InvalidInput(ValueError):
- """Raised when input source code fails all parse attempts."""
-
-
-class WriteBack(Enum):
- NO = 0
- YES = 1
- DIFF = 2
- CHECK = 3
-
- @classmethod
- def from_configuration(cls, *, check: bool, diff: bool) -> "WriteBack":
- if check and not diff:
- return cls.CHECK
-
- return cls.DIFF if diff else cls.YES
-
-
-class Changed(Enum):
- NO = 0
- CACHED = 1
- YES = 2
-
-
-class TargetVersion(Enum):
- PY27 = 2
- PY33 = 3
- PY34 = 4
- PY35 = 5
- PY36 = 6
- PY37 = 7
- PY38 = 8
-
- def is_python2(self) -> bool:
- return self is TargetVersion.PY27
-
-
-PY36_VERSIONS = {TargetVersion.PY36, TargetVersion.PY37, TargetVersion.PY38}
-
-
-class Feature(Enum):
- # All string literals are unicode
- UNICODE_LITERALS = 1
- F_STRINGS = 2
- NUMERIC_UNDERSCORES = 3
- TRAILING_COMMA_IN_CALL = 4
- TRAILING_COMMA_IN_DEF = 5
- # The following two feature-flags are mutually exclusive, and exactly one should be
- # set for every version of python.
- ASYNC_IDENTIFIERS = 6
- ASYNC_KEYWORDS = 7
- ASSIGNMENT_EXPRESSIONS = 8
- POS_ONLY_ARGUMENTS = 9
-
-
-VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = {
- TargetVersion.PY27: {Feature.ASYNC_IDENTIFIERS},
- TargetVersion.PY33: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
- TargetVersion.PY34: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
- TargetVersion.PY35: {
- Feature.UNICODE_LITERALS,
- Feature.TRAILING_COMMA_IN_CALL,
- Feature.ASYNC_IDENTIFIERS,
- },
- TargetVersion.PY36: {
- Feature.UNICODE_LITERALS,
- Feature.F_STRINGS,
- Feature.NUMERIC_UNDERSCORES,
- Feature.TRAILING_COMMA_IN_CALL,
- Feature.TRAILING_COMMA_IN_DEF,
- Feature.ASYNC_IDENTIFIERS,
- },
- TargetVersion.PY37: {
- Feature.UNICODE_LITERALS,
- Feature.F_STRINGS,
- Feature.NUMERIC_UNDERSCORES,
- Feature.TRAILING_COMMA_IN_CALL,
- Feature.TRAILING_COMMA_IN_DEF,
- Feature.ASYNC_KEYWORDS,
- },
- TargetVersion.PY38: {
- Feature.UNICODE_LITERALS,
- Feature.F_STRINGS,
- Feature.NUMERIC_UNDERSCORES,
- Feature.TRAILING_COMMA_IN_CALL,
- Feature.TRAILING_COMMA_IN_DEF,
- Feature.ASYNC_KEYWORDS,
- Feature.ASSIGNMENT_EXPRESSIONS,
- Feature.POS_ONLY_ARGUMENTS,
- },
-}
-
-
-@dataclass
-class FileMode:
- target_versions: Set[TargetVersion] = Factory(set)
- line_length: int = DEFAULT_LINE_LENGTH
- string_normalization: bool = True
- is_pyi: bool = False
-
- def get_cache_key(self) -> str:
- if self.target_versions:
- version_str = ",".join(
- str(version.value)
- for version in sorted(self.target_versions, key=lambda v: v.value)
- )
- else:
- version_str = "-"
- parts = [
- version_str,
- str(self.line_length),
- str(int(self.string_normalization)),
- str(int(self.is_pyi)),
- ]
- return ".".join(parts)
-
-
-def supports_feature(target_versions: Set[TargetVersion], feature: Feature) -> bool:
- return all(feature in VERSION_TO_FEATURES[version] for version in target_versions)
-
-
-def read_pyproject_toml(
- ctx: click.Context, param: click.Parameter, value: Union[str, int, bool, None]
-) -> Optional[str]:
- """Inject Black configuration from "pyproject.toml" into defaults in `ctx`.
-
- Returns the path to a successfully found and read configuration file, None
- otherwise.
- """
- assert not isinstance(value, (int, bool)), "Invalid parameter type passed"
- if not value:
- root = find_project_root(ctx.params.get("src", ()))
- path = root / "pyproject.toml"
- if path.is_file():
- value = str(path)
- else:
- return None
-
- try:
- pyproject_toml = toml.load(value)
- config = pyproject_toml.get("tool", {}).get("black", {})
- except (toml.TomlDecodeError, OSError) as e:
- raise click.FileError(
- filename=value, hint=f"Error reading configuration file: {e}"
- )
-
- if not config:
- return None
-
- if ctx.default_map is None:
- ctx.default_map = {}
- ctx.default_map.update( # type: ignore # bad types in .pyi
- {k.replace("--", "").replace("-", "_"): v for k, v in config.items()}
- )
- return value
-
-
-@click.command(context_settings=dict(help_option_names=["-h", "--help"]))
-@click.option("-c", "--code", type=str, help="Format the code passed in as a string.")
-@click.option(
- "-l",
- "--line-length",
- type=int,
- default=DEFAULT_LINE_LENGTH,
- help="How many characters per line to allow.",
- show_default=True,
-)
-@click.option(
- "-t",
- "--target-version",
- type=click.Choice([v.name.lower() for v in TargetVersion]),
- callback=lambda c, p, v: [TargetVersion[val.upper()] for val in v],
- multiple=True,
- help=(
- "Python versions that should be supported by Black's output. [default: "
- "per-file auto-detection]"
- ),
-)
-@click.option(
- "--py36",
- is_flag=True,
- help=(
- "Allow using Python 3.6-only syntax on all input files. This will put "
- "trailing commas in function signatures and calls also after *args and "
- "**kwargs. Deprecated; use --target-version instead. "
- "[default: per-file auto-detection]"
- ),
-)
-@click.option(
- "--pyi",
- is_flag=True,
- help=(
- "Format all input files like typing stubs regardless of file extension "
- "(useful when piping source on standard input)."
- ),
-)
-@click.option(
- "-S",
- "--skip-string-normalization",
- is_flag=True,
- help="Don't normalize string quotes or prefixes.",
-)
-@click.option(
- "--check",
- is_flag=True,
- help=(
- "Don't write the files back, just return the status. Return code 0 "
- "means nothing would change. Return code 1 means some files would be "
- "reformatted. Return code 123 means there was an internal error."
- ),
-)
-@click.option(
- "--diff",
- is_flag=True,
- help="Don't write the files back, just output a diff for each file on stdout.",
-)
-@click.option(
- "--fast/--safe",
- is_flag=True,
- help="If --fast given, skip temporary sanity checks. [default: --safe]",
-)
-@click.option(
- "--include",
- type=str,
- default=DEFAULT_INCLUDES,
- help=(
- "A regular expression that matches files and directories that should be "
- "included on recursive searches. An empty value means all files are "
- "included regardless of the name. Use forward slashes for directories on "
- "all platforms (Windows, too). Exclusions are calculated first, inclusions "
- "later."
- ),
- show_default=True,
-)
-@click.option(
- "--exclude",
- type=str,
- default=DEFAULT_EXCLUDES,
- help=(
- "A regular expression that matches files and directories that should be "
- "excluded on recursive searches. An empty value means no paths are excluded. "
- "Use forward slashes for directories on all platforms (Windows, too). "
- "Exclusions are calculated first, inclusions later."
- ),
- show_default=True,
-)
-@click.option(
- "-q",
- "--quiet",
- is_flag=True,
- help=(
- "Don't emit non-error messages to stderr. Errors are still emitted; "
- "silence those with 2>/dev/null."
- ),
-)
-@click.option(
- "-v",
- "--verbose",
- is_flag=True,
- help=(
- "Also emit messages to stderr about files that were not changed or were "
- "ignored due to --exclude=."
- ),
-)
-@click.version_option(version=__version__)
-@click.argument(
- "src",
- nargs=-1,
- type=click.Path(
- exists=True, file_okay=True, dir_okay=True, readable=True, allow_dash=True
- ),
- is_eager=True,
-)
-@click.option(
- "--config",
- type=click.Path(
- exists=False, file_okay=True, dir_okay=False, readable=True, allow_dash=False
- ),
- is_eager=True,
- callback=read_pyproject_toml,
- help="Read configuration from PATH.",
-)
-@click.pass_context
-def main(
- ctx: click.Context,
- code: Optional[str],
- line_length: int,
- target_version: List[TargetVersion],
- check: bool,
- diff: bool,
- fast: bool,
- pyi: bool,
- py36: bool,
- skip_string_normalization: bool,
- quiet: bool,
- verbose: bool,
- include: str,
- exclude: str,
- src: Tuple[str],
- config: Optional[str],
-) -> None:
- """The uncompromising code formatter."""
- write_back = WriteBack.from_configuration(check=check, diff=diff)
- if target_version:
- if py36:
- err(f"Cannot use both --target-version and --py36")
- ctx.exit(2)
- else:
- versions = set(target_version)
- elif py36:
- err(
- "--py36 is deprecated and will be removed in a future version. "
- "Use --target-version py36 instead."
- )
- versions = PY36_VERSIONS
- else:
- # We'll autodetect later.
- versions = set()
- mode = FileMode(
- target_versions=versions,
- line_length=line_length,
- is_pyi=pyi,
- string_normalization=not skip_string_normalization,
- )
- if config and verbose:
- out(f"Using configuration from {config}.", bold=False, fg="blue")
- if code is not None:
- print(format_str(code, mode=mode))
- ctx.exit(0)
- try:
- include_regex = re_compile_maybe_verbose(include)
- except re.error:
- err(f"Invalid regular expression for include given: {include!r}")
- ctx.exit(2)
- try:
- exclude_regex = re_compile_maybe_verbose(exclude)
- except re.error:
- err(f"Invalid regular expression for exclude given: {exclude!r}")
- ctx.exit(2)
- report = Report(check=check, quiet=quiet, verbose=verbose)
- root = find_project_root(src)
- sources: Set[Path] = set()
- path_empty(src, quiet, verbose, ctx)
- for s in src:
- p = Path(s)
- if p.is_dir():
- sources.update(
- gen_python_files_in_dir(p, root, include_regex, exclude_regex, report)
- )
- elif p.is_file() or s == "-":
- # if a file was explicitly given, we don't care about its extension
- sources.add(p)
- else:
- err(f"invalid path: {s}")
- if len(sources) == 0:
- if verbose or not quiet:
- out("No Python files are present to be formatted. Nothing to do 😴")
- ctx.exit(0)
-
- if len(sources) == 1:
- reformat_one(
- src=sources.pop(),
- fast=fast,
- write_back=write_back,
- mode=mode,
- report=report,
- )
- else:
- reformat_many(
- sources=sources, fast=fast, write_back=write_back, mode=mode, report=report
- )
-
- if verbose or not quiet:
- out("Oh no! 💥 💔 💥" if report.return_code else "All done! ✨ 🍰 ✨")
- click.secho(str(report), err=True)
- ctx.exit(report.return_code)
-
-
-def path_empty(src: Tuple[str], quiet: bool, verbose: bool, ctx: click.Context) -> None:
- """
- Exit if there is no `src` provided for formatting
- """
- if not src:
- if verbose or not quiet:
- out("No Path provided. Nothing to do 😴")
- ctx.exit(0)
-
-
-def reformat_one(
- src: Path, fast: bool, write_back: WriteBack, mode: FileMode, report: "Report"
-) -> None:
- """Reformat a single file under `src` without spawning child processes.
-
- `fast`, `write_back`, and `mode` options are passed to
- :func:`format_file_in_place` or :func:`format_stdin_to_stdout`.
- """
- try:
- changed = Changed.NO
- if not src.is_file() and str(src) == "-":
- if format_stdin_to_stdout(fast=fast, write_back=write_back, mode=mode):
- changed = Changed.YES
- else:
- cache: Cache = {}
- if write_back != WriteBack.DIFF:
- cache = read_cache(mode)
- res_src = src.resolve()
- if res_src in cache and cache[res_src] == get_cache_info(res_src):
- changed = Changed.CACHED
- if changed is not Changed.CACHED and format_file_in_place(
- src, fast=fast, write_back=write_back, mode=mode
- ):
- changed = Changed.YES
- if (write_back is WriteBack.YES and changed is not Changed.CACHED) or (
- write_back is WriteBack.CHECK and changed is Changed.NO
- ):
- write_cache(cache, [src], mode)
- report.done(src, changed)
- except Exception as exc:
- report.failed(src, str(exc))
-
-
-def reformat_many(
- sources: Set[Path],
- fast: bool,
- write_back: WriteBack,
- mode: FileMode,
- report: "Report",
-) -> None:
- """Reformat multiple files using a ProcessPoolExecutor."""
- loop = asyncio.get_event_loop()
- worker_count = os.cpu_count()
- if sys.platform == "win32":
- # Work around https://bugs.python.org/issue26903
- worker_count = min(worker_count, 61)
- executor = ProcessPoolExecutor(max_workers=worker_count)
- try:
- loop.run_until_complete(
- schedule_formatting(
- sources=sources,
- fast=fast,
- write_back=write_back,
- mode=mode,
- report=report,
- loop=loop,
- executor=executor,
- )
- )
- finally:
- shutdown(loop)
- executor.shutdown()
-
-
-async def schedule_formatting(
- sources: Set[Path],
- fast: bool,
- write_back: WriteBack,
- mode: FileMode,
- report: "Report",
- loop: asyncio.AbstractEventLoop,
- executor: Executor,
-) -> None:
- """Run formatting of `sources` in parallel using the provided `executor`.
-
- (Use ProcessPoolExecutors for actual parallelism.)
-
- `write_back`, `fast`, and `mode` options are passed to
- :func:`format_file_in_place`.
- """
- cache: Cache = {}
- if write_back != WriteBack.DIFF:
- cache = read_cache(mode)
- sources, cached = filter_cached(cache, sources)
- for src in sorted(cached):
- report.done(src, Changed.CACHED)
- if not sources:
- return
-
- cancelled = []
- sources_to_cache = []
- lock = None
- if write_back == WriteBack.DIFF:
- # For diff output, we need locks to ensure we don't interleave output
- # from different processes.
- manager = Manager()
- lock = manager.Lock()
- tasks = {
- asyncio.ensure_future(
- loop.run_in_executor(
- executor, format_file_in_place, src, fast, mode, write_back, lock
- )
- ): src
- for src in sorted(sources)
- }
- pending: Iterable[asyncio.Future] = tasks.keys()
- try:
- loop.add_signal_handler(signal.SIGINT, cancel, pending)
- loop.add_signal_handler(signal.SIGTERM, cancel, pending)
- except NotImplementedError:
- # There are no good alternatives for these on Windows.
- pass
- while pending:
- done, _ = await asyncio.wait(pending, return_when=asyncio.FIRST_COMPLETED)
- for task in done:
- src = tasks.pop(task)
- if task.cancelled():
- cancelled.append(task)
- elif task.exception():
- report.failed(src, str(task.exception()))
- else:
- changed = Changed.YES if task.result() else Changed.NO
- # If the file was written back or was successfully checked as
- # well-formatted, store this information in the cache.
- if write_back is WriteBack.YES or (
- write_back is WriteBack.CHECK and changed is Changed.NO
- ):
- sources_to_cache.append(src)
- report.done(src, changed)
- if cancelled:
- await asyncio.gather(*cancelled, loop=loop, return_exceptions=True)
- if sources_to_cache:
- write_cache(cache, sources_to_cache, mode)
-
-
-def format_file_in_place(
- src: Path,
- fast: bool,
- mode: FileMode,
- write_back: WriteBack = WriteBack.NO,
- lock: Any = None, # multiprocessing.Manager().Lock() is some crazy proxy
-) -> bool:
- """Format file under `src` path. Return True if changed.
-
- If `write_back` is DIFF, write a diff to stdout. If it is YES, write reformatted
- code to the file.
- `mode` and `fast` options are passed to :func:`format_file_contents`.
- """
- if src.suffix == ".pyi":
- mode = evolve(mode, is_pyi=True)
-
- then = datetime.utcfromtimestamp(src.stat().st_mtime)
- with open(src, "rb") as buf:
- src_contents, encoding, newline = decode_bytes(buf.read())
- try:
- dst_contents = format_file_contents(src_contents, fast=fast, mode=mode)
- except NothingChanged:
- return False
-
- if write_back == write_back.YES:
- with open(src, "w", encoding=encoding, newline=newline) as f:
- f.write(dst_contents)
- elif write_back == write_back.DIFF:
- now = datetime.utcnow()
- src_name = f"{src}\t{then} +0000"
- dst_name = f"{src}\t{now} +0000"
- diff_contents = diff(src_contents, dst_contents, src_name, dst_name)
-
- with lock or nullcontext():
- f = io.TextIOWrapper(
- sys.stdout.buffer,
- encoding=encoding,
- newline=newline,
- write_through=True,
- )
- f.write(diff_contents)
- f.detach()
-
- return True
-
-
-def format_stdin_to_stdout(
- fast: bool, *, write_back: WriteBack = WriteBack.NO, mode: FileMode
-) -> bool:
- """Format file on stdin. Return True if changed.
-
- If `write_back` is YES, write reformatted code back to stdout. If it is DIFF,
- write a diff to stdout. The `mode` argument is passed to
- :func:`format_file_contents`.
- """
- then = datetime.utcnow()
- src, encoding, newline = decode_bytes(sys.stdin.buffer.read())
- dst = src
- try:
- dst = format_file_contents(src, fast=fast, mode=mode)
- return True
-
- except NothingChanged:
- return False
-
- finally:
- f = io.TextIOWrapper(
- sys.stdout.buffer, encoding=encoding, newline=newline, write_through=True
- )
- if write_back == WriteBack.YES:
- f.write(dst)
- elif write_back == WriteBack.DIFF:
- now = datetime.utcnow()
- src_name = f"STDIN\t{then} +0000"
- dst_name = f"STDOUT\t{now} +0000"
- f.write(diff(src, dst, src_name, dst_name))
- f.detach()
-
-
-def format_file_contents(
- src_contents: str, *, fast: bool, mode: FileMode
-) -> FileContent:
- """Reformat contents a file and return new contents.
-
- If `fast` is False, additionally confirm that the reformatted code is
- valid by calling :func:`assert_equivalent` and :func:`assert_stable` on it.
- `mode` is passed to :func:`format_str`.
- """
- if src_contents.strip() == "":
- raise NothingChanged
-
- dst_contents = format_str(src_contents, mode=mode)
- if src_contents == dst_contents:
- raise NothingChanged
-
- if not fast:
- assert_equivalent(src_contents, dst_contents)
- assert_stable(src_contents, dst_contents, mode=mode)
- return dst_contents
-
-
-def format_str(src_contents: str, *, mode: FileMode) -> FileContent:
- """Reformat a string and return new contents.
-
- `mode` determines formatting options, such as how many characters per line are
- allowed.
- """
- src_node = lib2to3_parse(src_contents.lstrip(), mode.target_versions)
- dst_contents = []
- future_imports = get_future_imports(src_node)
- if mode.target_versions:
- versions = mode.target_versions
- else:
- versions = detect_target_versions(src_node)
- normalize_fmt_off(src_node)
- lines = LineGenerator(
- remove_u_prefix="unicode_literals" in future_imports
- or supports_feature(versions, Feature.UNICODE_LITERALS),
- is_pyi=mode.is_pyi,
- normalize_strings=mode.string_normalization,
- )
- elt = EmptyLineTracker(is_pyi=mode.is_pyi)
- empty_line = Line()
- after = 0
- split_line_features = {
- feature
- for feature in {Feature.TRAILING_COMMA_IN_CALL, Feature.TRAILING_COMMA_IN_DEF}
- if supports_feature(versions, feature)
- }
- for current_line in lines.visit(src_node):
- for _ in range(after):
- dst_contents.append(str(empty_line))
- before, after = elt.maybe_empty_lines(current_line)
- for _ in range(before):
- dst_contents.append(str(empty_line))
- for line in split_line(
- current_line, line_length=mode.line_length, features=split_line_features
- ):
- dst_contents.append(str(line))
- return "".join(dst_contents)
-
-
-def decode_bytes(src: bytes) -> Tuple[FileContent, Encoding, NewLine]:
- """Return a tuple of (decoded_contents, encoding, newline).
-
- `newline` is either CRLF or LF but `decoded_contents` is decoded with
- universal newlines (i.e. only contains LF).
- """
- srcbuf = io.BytesIO(src)
- encoding, lines = tokenize.detect_encoding(srcbuf.readline)
- if not lines:
- return "", encoding, "\n"
-
- newline = "\r\n" if b"\r\n" == lines[0][-2:] else "\n"
- srcbuf.seek(0)
- with io.TextIOWrapper(srcbuf, encoding) as tiow:
- return tiow.read(), encoding, newline
-
-
-def get_grammars(target_versions: Set[TargetVersion]) -> List[Grammar]:
- if not target_versions:
- # No target_version specified, so try all grammars.
- return [
- # Python 3.7+
- pygram.python_grammar_no_print_statement_no_exec_statement_async_keywords,
- # Python 3.0-3.6
- pygram.python_grammar_no_print_statement_no_exec_statement,
- # Python 2.7 with future print_function import
- pygram.python_grammar_no_print_statement,
- # Python 2.7
- pygram.python_grammar,
- ]
- elif all(version.is_python2() for version in target_versions):
- # Python 2-only code, so try Python 2 grammars.
- return [
- # Python 2.7 with future print_function import
- pygram.python_grammar_no_print_statement,
- # Python 2.7
- pygram.python_grammar,
- ]
- else:
- # Python 3-compatible code, so only try Python 3 grammar.
- grammars = []
- # If we have to parse both, try to parse async as a keyword first
- if not supports_feature(target_versions, Feature.ASYNC_IDENTIFIERS):
- # Python 3.7+
- grammars.append(
- pygram.python_grammar_no_print_statement_no_exec_statement_async_keywords # noqa: B950
- )
- if not supports_feature(target_versions, Feature.ASYNC_KEYWORDS):
- # Python 3.0-3.6
- grammars.append(pygram.python_grammar_no_print_statement_no_exec_statement)
- # At least one of the above branches must have been taken, because every Python
- # version has exactly one of the two 'ASYNC_*' flags
- return grammars
-
-
-def lib2to3_parse(src_txt: str, target_versions: Iterable[TargetVersion] = ()) -> Node:
- """Given a string with source, return the lib2to3 Node."""
- if src_txt[-1:] != "\n":
- src_txt += "\n"
-
- for grammar in get_grammars(set(target_versions)):
- drv = driver.Driver(grammar, pytree.convert)
- try:
- result = drv.parse_string(src_txt, True)
- break
-
- except ParseError as pe:
- lineno, column = pe.context[1]
- lines = src_txt.splitlines()
- try:
- faulty_line = lines[lineno - 1]
- except IndexError:
- faulty_line = "<line number missing in source>"
- exc = InvalidInput(f"Cannot parse: {lineno}:{column}: {faulty_line}")
- else:
- raise exc from None
-
- if isinstance(result, Leaf):
- result = Node(syms.file_input, [result])
- return result
-
-
-def lib2to3_unparse(node: Node) -> str:
- """Given a lib2to3 node, return its string representation."""
- code = str(node)
- return code
-
-
-T = TypeVar("T")
-
-
-class Visitor(Generic[T]):
- """Basic lib2to3 visitor that yields things of type `T` on `visit()`."""
-
- def visit(self, node: LN) -> Iterator[T]:
- """Main method to visit `node` and its children.
-
- It tries to find a `visit_*()` method for the given `node.type`, like
- `visit_simple_stmt` for Node objects or `visit_INDENT` for Leaf objects.
- If no dedicated `visit_*()` method is found, chooses `visit_default()`
- instead.
-
- Then yields objects of type `T` from the selected visitor.
- """
- if node.type < 256:
- name = token.tok_name[node.type]
- else:
- name = type_repr(node.type)
- yield from getattr(self, f"visit_{name}", self.visit_default)(node)
-
- def visit_default(self, node: LN) -> Iterator[T]:
- """Default `visit_*()` implementation. Recurses to children of `node`."""
- if isinstance(node, Node):
- for child in node.children:
- yield from self.visit(child)
-
-
-@dataclass
-class DebugVisitor(Visitor[T]):
- tree_depth: int = 0
-
- def visit_default(self, node: LN) -> Iterator[T]:
- indent = " " * (2 * self.tree_depth)
- if isinstance(node, Node):
- _type = type_repr(node.type)
- out(f"{indent}{_type}", fg="yellow")
- self.tree_depth += 1
- for child in node.children:
- yield from self.visit(child)
-
- self.tree_depth -= 1
- out(f"{indent}/{_type}", fg="yellow", bold=False)
- else:
- _type = token.tok_name.get(node.type, str(node.type))
- out(f"{indent}{_type}", fg="blue", nl=False)
- if node.prefix:
- # We don't have to handle prefixes for `Node` objects since
- # that delegates to the first child anyway.
- out(f" {node.prefix!r}", fg="green", bold=False, nl=False)
- out(f" {node.value!r}", fg="blue", bold=False)
-
- @classmethod
- def show(cls, code: Union[str, Leaf, Node]) -> None:
- """Pretty-print the lib2to3 AST of a given string of `code`.
-
- Convenience method for debugging.
- """
- v: DebugVisitor[None] = DebugVisitor()
- if isinstance(code, str):
- code = lib2to3_parse(code)
- list(v.visit(code))
-
-
-WHITESPACE = {token.DEDENT, token.INDENT, token.NEWLINE}
-STATEMENT = {
- syms.if_stmt,
- syms.while_stmt,
- syms.for_stmt,
- syms.try_stmt,
- syms.except_clause,
- syms.with_stmt,
- syms.funcdef,
- syms.classdef,
-}
-STANDALONE_COMMENT = 153
-token.tok_name[STANDALONE_COMMENT] = "STANDALONE_COMMENT"
-LOGIC_OPERATORS = {"and", "or"}
-COMPARATORS = {
- token.LESS,
- token.GREATER,
- token.EQEQUAL,
- token.NOTEQUAL,
- token.LESSEQUAL,
- token.GREATEREQUAL,
-}
-MATH_OPERATORS = {
- token.VBAR,
- token.CIRCUMFLEX,
- token.AMPER,
- token.LEFTSHIFT,
- token.RIGHTSHIFT,
- token.PLUS,
- token.MINUS,
- token.STAR,
- token.SLASH,
- token.DOUBLESLASH,
- token.PERCENT,
- token.AT,
- token.TILDE,
- token.DOUBLESTAR,
-}
-STARS = {token.STAR, token.DOUBLESTAR}
-VARARGS_SPECIALS = STARS | {token.SLASH}
-VARARGS_PARENTS = {
- syms.arglist,
- syms.argument, # double star in arglist
- syms.trailer, # single argument to call
- syms.typedargslist,
- syms.varargslist, # lambdas
-}
-UNPACKING_PARENTS = {
- syms.atom, # single element of a list or set literal
- syms.dictsetmaker,
- syms.listmaker,
- syms.testlist_gexp,
- syms.testlist_star_expr,
-}
-TEST_DESCENDANTS = {
- syms.test,
- syms.lambdef,
- syms.or_test,
- syms.and_test,
- syms.not_test,
- syms.comparison,
- syms.star_expr,
- syms.expr,
- syms.xor_expr,
- syms.and_expr,
- syms.shift_expr,
- syms.arith_expr,
- syms.trailer,
- syms.term,
- syms.power,
-}
-ASSIGNMENTS = {
- "=",
- "+=",
- "-=",
- "*=",
- "@=",
- "/=",
- "%=",
- "&=",
- "|=",
- "^=",
- "<<=",
- ">>=",
- "**=",
- "//=",
-}
-COMPREHENSION_PRIORITY = 20
-COMMA_PRIORITY = 18
-TERNARY_PRIORITY = 16
-LOGIC_PRIORITY = 14
-STRING_PRIORITY = 12
-COMPARATOR_PRIORITY = 10
-MATH_PRIORITIES = {
- token.VBAR: 9,
- token.CIRCUMFLEX: 8,
- token.AMPER: 7,
- token.LEFTSHIFT: 6,
- token.RIGHTSHIFT: 6,
- token.PLUS: 5,
- token.MINUS: 5,
- token.STAR: 4,
- token.SLASH: 4,
- token.DOUBLESLASH: 4,
- token.PERCENT: 4,
- token.AT: 4,
- token.TILDE: 3,
- token.DOUBLESTAR: 2,
-}
-DOT_PRIORITY = 1
-
-
-@dataclass
-class BracketTracker:
- """Keeps track of brackets on a line."""
-
- depth: int = 0
- bracket_match: Dict[Tuple[Depth, NodeType], Leaf] = Factory(dict)
- delimiters: Dict[LeafID, Priority] = Factory(dict)
- previous: Optional[Leaf] = None
- _for_loop_depths: List[int] = Factory(list)
- _lambda_argument_depths: List[int] = Factory(list)
-
- def mark(self, leaf: Leaf) -> None:
- """Mark `leaf` with bracket-related metadata. Keep track of delimiters.
-
- All leaves receive an int `bracket_depth` field that stores how deep
- within brackets a given leaf is. 0 means there are no enclosing brackets
- that started on this line.
-
- If a leaf is itself a closing bracket, it receives an `opening_bracket`
- field that it forms a pair with. This is a one-directional link to
- avoid reference cycles.
-
- If a leaf is a delimiter (a token on which Black can split the line if
- needed) and it's on depth 0, its `id()` is stored in the tracker's
- `delimiters` field.
- """
- if leaf.type == token.COMMENT:
- return
-
- self.maybe_decrement_after_for_loop_variable(leaf)
- self.maybe_decrement_after_lambda_arguments(leaf)
- if leaf.type in CLOSING_BRACKETS:
- self.depth -= 1
- opening_bracket = self.bracket_match.pop((self.depth, leaf.type))
- leaf.opening_bracket = opening_bracket
- leaf.bracket_depth = self.depth
- if self.depth == 0:
- delim = is_split_before_delimiter(leaf, self.previous)
- if delim and self.previous is not None:
- self.delimiters[id(self.previous)] = delim
- else:
- delim = is_split_after_delimiter(leaf, self.previous)
- if delim:
- self.delimiters[id(leaf)] = delim
- if leaf.type in OPENING_BRACKETS:
- self.bracket_match[self.depth, BRACKET[leaf.type]] = leaf
- self.depth += 1
- self.previous = leaf
- self.maybe_increment_lambda_arguments(leaf)
- self.maybe_increment_for_loop_variable(leaf)
-
- def any_open_brackets(self) -> bool:
- """Return True if there is an yet unmatched open bracket on the line."""
- return bool(self.bracket_match)
-
- def max_delimiter_priority(self, exclude: Iterable[LeafID] = ()) -> Priority:
- """Return the highest priority of a delimiter found on the line.
-
- Values are consistent with what `is_split_*_delimiter()` return.
- Raises ValueError on no delimiters.
- """
- return max(v for k, v in self.delimiters.items() if k not in exclude)
-
- def delimiter_count_with_priority(self, priority: Priority = 0) -> int:
- """Return the number of delimiters with the given `priority`.
-
- If no `priority` is passed, defaults to max priority on the line.
- """
- if not self.delimiters:
- return 0
-
- priority = priority or self.max_delimiter_priority()
- return sum(1 for p in self.delimiters.values() if p == priority)
-
- def maybe_increment_for_loop_variable(self, leaf: Leaf) -> bool:
- """In a for loop, or comprehension, the variables are often unpacks.
-
- To avoid splitting on the comma in this situation, increase the depth of
- tokens between `for` and `in`.
- """
- if leaf.type == token.NAME and leaf.value == "for":
- self.depth += 1
- self._for_loop_depths.append(self.depth)
- return True
-
- return False
-
- def maybe_decrement_after_for_loop_variable(self, leaf: Leaf) -> bool:
- """See `maybe_increment_for_loop_variable` above for explanation."""
- if (
- self._for_loop_depths
- and self._for_loop_depths[-1] == self.depth
- and leaf.type == token.NAME
- and leaf.value == "in"
- ):
- self.depth -= 1
- self._for_loop_depths.pop()
- return True
-
- return False
-
- def maybe_increment_lambda_arguments(self, leaf: Leaf) -> bool:
- """In a lambda expression, there might be more than one argument.
-
- To avoid splitting on the comma in this situation, increase the depth of
- tokens between `lambda` and `:`.
- """
- if leaf.type == token.NAME and leaf.value == "lambda":
- self.depth += 1
- self._lambda_argument_depths.append(self.depth)
- return True
-
- return False
-
- def maybe_decrement_after_lambda_arguments(self, leaf: Leaf) -> bool:
- """See `maybe_increment_lambda_arguments` above for explanation."""
- if (
- self._lambda_argument_depths
- and self._lambda_argument_depths[-1] == self.depth
- and leaf.type == token.COLON
- ):
- self.depth -= 1
- self._lambda_argument_depths.pop()
- return True
-
- return False
-
- def get_open_lsqb(self) -> Optional[Leaf]:
- """Return the most recent opening square bracket (if any)."""
- return self.bracket_match.get((self.depth - 1, token.RSQB))
-
-
-@dataclass
-class Line:
- """Holds leaves and comments. Can be printed with `str(line)`."""
-
- depth: int = 0
- leaves: List[Leaf] = Factory(list)
- comments: Dict[LeafID, List[Leaf]] = Factory(dict) # keys ordered like `leaves`
- bracket_tracker: BracketTracker = Factory(BracketTracker)
- inside_brackets: bool = False
- should_explode: bool = False
-
- def append(self, leaf: Leaf, preformatted: bool = False) -> None:
- """Add a new `leaf` to the end of the line.
-
- Unless `preformatted` is True, the `leaf` will receive a new consistent
- whitespace prefix and metadata applied by :class:`BracketTracker`.
- Trailing commas are maybe removed, unpacked for loop variables are
- demoted from being delimiters.
-
- Inline comments are put aside.
- """
- has_value = leaf.type in BRACKETS or bool(leaf.value.strip())
- if not has_value:
- return
-
- if token.COLON == leaf.type and self.is_class_paren_empty:
- del self.leaves[-2:]
- if self.leaves and not preformatted:
- # Note: at this point leaf.prefix should be empty except for
- # imports, for which we only preserve newlines.
- leaf.prefix += whitespace(
- leaf, complex_subscript=self.is_complex_subscript(leaf)
- )
- if self.inside_brackets or not preformatted:
- self.bracket_tracker.mark(leaf)
- self.maybe_remove_trailing_comma(leaf)
- if not self.append_comment(leaf):
- self.leaves.append(leaf)
-
- def append_safe(self, leaf: Leaf, preformatted: bool = False) -> None:
- """Like :func:`append()` but disallow invalid standalone comment structure.
-
- Raises ValueError when any `leaf` is appended after a standalone comment
- or when a standalone comment is not the first leaf on the line.
- """
- if self.bracket_tracker.depth == 0:
- if self.is_comment:
- raise ValueError("cannot append to standalone comments")
-
- if self.leaves and leaf.type == STANDALONE_COMMENT:
- raise ValueError(
- "cannot append standalone comments to a populated line"
- )
-
- self.append(leaf, preformatted=preformatted)
-
- @property
- def is_comment(self) -> bool:
- """Is this line a standalone comment?"""
- return len(self.leaves) == 1 and self.leaves[0].type == STANDALONE_COMMENT
-
- @property
- def is_decorator(self) -> bool:
- """Is this line a decorator?"""
- return bool(self) and self.leaves[0].type == token.AT
-
- @property
- def is_import(self) -> bool:
- """Is this an import line?"""
- return bool(self) and is_import(self.leaves[0])
-
- @property
- def is_class(self) -> bool:
- """Is this line a class definition?"""
- return (
- bool(self)
- and self.leaves[0].type == token.NAME
- and self.leaves[0].value == "class"
- )
-
- @property
- def is_stub_class(self) -> bool:
- """Is this line a class definition with a body consisting only of "..."?"""
- return self.is_class and self.leaves[-3:] == [
- Leaf(token.DOT, ".") for _ in range(3)
- ]
-
- @property
- def is_collection_with_optional_trailing_comma(self) -> bool:
- """Is this line a collection literal with a trailing comma that's optional?
-
- Note that the trailing comma in a 1-tuple is not optional.
- """
- if not self.leaves or len(self.leaves) < 4:
- return False
- # Look for and address a trailing colon.
- if self.leaves[-1].type == token.COLON:
- closer = self.leaves[-2]
- close_index = -2
- else:
- closer = self.leaves[-1]
- close_index = -1
- if closer.type not in CLOSING_BRACKETS or self.inside_brackets:
- return False
- if closer.type == token.RPAR:
- # Tuples require an extra check, because if there's only
- # one element in the tuple removing the comma unmakes the
- # tuple.
- #
- # We also check for parens before looking for the trailing
- # comma because in some cases (eg assigning a dict
- # literal) the literal gets wrapped in temporary parens
- # during parsing. This case is covered by the
- # collections.py test data.
- opener = closer.opening_bracket
- for _open_index, leaf in enumerate(self.leaves):
- if leaf is opener:
- break
- else:
- # Couldn't find the matching opening paren, play it safe.
- return False
- commas = 0
- comma_depth = self.leaves[close_index - 1].bracket_depth
- for leaf in self.leaves[_open_index + 1 : close_index]:
- if leaf.bracket_depth == comma_depth and leaf.type == token.COMMA:
- commas += 1
- if commas > 1:
- # We haven't looked yet for the trailing comma because
- # we might also have caught noop parens.
- return self.leaves[close_index - 1].type == token.COMMA
- elif commas == 1:
- return False # it's either a one-tuple or didn't have a trailing comma
- if self.leaves[close_index - 1].type in CLOSING_BRACKETS:
- close_index -= 1
- closer = self.leaves[close_index]
- if closer.type == token.RPAR:
- # TODO: this is a gut feeling. Will we ever see this?
- return False
- if self.leaves[close_index - 1].type != token.COMMA:
- return False
- return True
-
- @property
- def is_def(self) -> bool:
- """Is this a function definition? (Also returns True for async defs.)"""
- try:
- first_leaf = self.leaves[0]
- except IndexError:
- return False
-
- try:
- second_leaf: Optional[Leaf] = self.leaves[1]
- except IndexError:
- second_leaf = None
- return (first_leaf.type == token.NAME and first_leaf.value == "def") or (
- first_leaf.type == token.ASYNC
- and second_leaf is not None
- and second_leaf.type == token.NAME
- and second_leaf.value == "def"
- )
-
- @property
- def is_class_paren_empty(self) -> bool:
- """Is this a class with no base classes but using parentheses?
-
- Those are unnecessary and should be removed.
- """
- return (
- bool(self)
- and len(self.leaves) == 4
- and self.is_class
- and self.leaves[2].type == token.LPAR
- and self.leaves[2].value == "("
- and self.leaves[3].type == token.RPAR
- and self.leaves[3].value == ")"
- )
-
- @property
- def is_triple_quoted_string(self) -> bool:
- """Is the line a triple quoted string?"""
- return (
- bool(self)
- and self.leaves[0].type == token.STRING
- and self.leaves[0].value.startswith(('"""', "'''"))
- )
-
- def contains_standalone_comments(self, depth_limit: int = sys.maxsize) -> bool:
- """If so, needs to be split before emitting."""
- for leaf in self.leaves:
- if leaf.type == STANDALONE_COMMENT:
- if leaf.bracket_depth <= depth_limit:
- return True
- return False
-
- def contains_uncollapsable_type_comments(self) -> bool:
- ignored_ids = set()
- try:
- last_leaf = self.leaves[-1]
- ignored_ids.add(id(last_leaf))
- if last_leaf.type == token.COMMA or (
- last_leaf.type == token.RPAR and not last_leaf.value
- ):
- # When trailing commas or optional parens are inserted by Black for
- # consistency, comments after the previous last element are not moved
- # (they don't have to, rendering will still be correct). So we ignore
- # trailing commas and invisible.
- last_leaf = self.leaves[-2]
- ignored_ids.add(id(last_leaf))
- except IndexError:
- return False
-
- # A type comment is uncollapsable if it is attached to a leaf
- # that isn't at the end of the line (since that could cause it
- # to get associated to a different argument) or if there are
- # comments before it (since that could cause it to get hidden
- # behind a comment.
- comment_seen = False
- for leaf_id, comments in self.comments.items():
- for comment in comments:
- if is_type_comment(comment):
- if leaf_id not in ignored_ids or comment_seen:
- return True
-
- comment_seen = True
-
- return False
-
- def contains_unsplittable_type_ignore(self) -> bool:
- if not self.leaves:
- return False
-
- # If a 'type: ignore' is attached to the end of a line, we
- # can't split the line, because we can't know which of the
- # subexpressions the ignore was meant to apply to.
- #
- # We only want this to apply to actual physical lines from the
- # original source, though: we don't want the presence of a
- # 'type: ignore' at the end of a multiline expression to
- # justify pushing it all onto one line. Thus we
- # (unfortunately) need to check the actual source lines and
- # only report an unsplittable 'type: ignore' if this line was
- # one line in the original code.
- if self.leaves[0].lineno == self.leaves[-1].lineno:
- for comment in self.comments.get(id(self.leaves[-1]), []):
- if is_type_comment(comment, " ignore"):
- return True
-
- return False
-
- def contains_multiline_strings(self) -> bool:
- for leaf in self.leaves:
- if is_multiline_string(leaf):
- return True
-
- return False
-
- def maybe_remove_trailing_comma(self, closing: Leaf) -> bool:
- """Remove trailing comma if there is one and it's safe."""
- if not (self.leaves and self.leaves[-1].type == token.COMMA):
- return False
- # We remove trailing commas only in the case of importing a
- # single name from a module.
- if not (
- self.leaves
- and self.is_import
- and len(self.leaves) > 4
- and self.leaves[-1].type == token.COMMA
- and closing.type in CLOSING_BRACKETS
- and self.leaves[-4].type == token.NAME
- and (
- # regular `from foo import bar,`
- self.leaves[-4].value == "import"
- # `from foo import (bar as baz,)
- or (
- len(self.leaves) > 6
- and self.leaves[-6].value == "import"
- and self.leaves[-3].value == "as"
- )
- # `from foo import bar as baz,`
- or (
- len(self.leaves) > 5
- and self.leaves[-5].value == "import"
- and self.leaves[-3].value == "as"
- )
- )
- and closing.type == token.RPAR
- ):
- return False
-
- self.remove_trailing_comma()
- return True
-
- def append_comment(self, comment: Leaf) -> bool:
- """Add an inline or standalone comment to the line."""
- if (
- comment.type == STANDALONE_COMMENT
- and self.bracket_tracker.any_open_brackets()
- ):
- comment.prefix = ""
- return False
-
- if comment.type != token.COMMENT:
- return False
-
- if not self.leaves:
- comment.type = STANDALONE_COMMENT
- comment.prefix = ""
- return False
-
- last_leaf = self.leaves[-1]
- if (
- last_leaf.type == token.RPAR
- and not last_leaf.value
- and last_leaf.parent
- and len(list(last_leaf.parent.leaves())) <= 3
- and not is_type_comment(comment)
- ):
- # Comments on an optional parens wrapping a single leaf should belong to
- # the wrapped node except if it's a type comment. Pinning the comment like
- # this avoids unstable formatting caused by comment migration.
- if len(self.leaves) < 2:
- comment.type = STANDALONE_COMMENT
- comment.prefix = ""
- return False
- last_leaf = self.leaves[-2]
- self.comments.setdefault(id(last_leaf), []).append(comment)
- return True
-
- def comments_after(self, leaf: Leaf) -> List[Leaf]:
- """Generate comments that should appear directly after `leaf`."""
- return self.comments.get(id(leaf), [])
-
- def remove_trailing_comma(self) -> None:
- """Remove the trailing comma and moves the comments attached to it."""
- trailing_comma = self.leaves.pop()
- trailing_comma_comments = self.comments.pop(id(trailing_comma), [])
- self.comments.setdefault(id(self.leaves[-1]), []).extend(
- trailing_comma_comments
- )
-
- def is_complex_subscript(self, leaf: Leaf) -> bool:
- """Return True iff `leaf` is part of a slice with non-trivial exprs."""
- open_lsqb = self.bracket_tracker.get_open_lsqb()
- if open_lsqb is None:
- return False
-
- subscript_start = open_lsqb.next_sibling
-
- if isinstance(subscript_start, Node):
- if subscript_start.type == syms.listmaker:
- return False
-
- if subscript_start.type == syms.subscriptlist:
- subscript_start = child_towards(subscript_start, leaf)
- return subscript_start is not None and any(
- n.type in TEST_DESCENDANTS for n in subscript_start.pre_order()
- )
-
- def __str__(self) -> str:
- """Render the line."""
- if not self:
- return "\n"
-
- indent = " " * self.depth
- leaves = iter(self.leaves)
- first = next(leaves)
- res = f"{first.prefix}{indent}{first.value}"
- for leaf in leaves:
- res += str(leaf)
- for comment in itertools.chain.from_iterable(self.comments.values()):
- res += str(comment)
- return res + "\n"
-
- def __bool__(self) -> bool:
- """Return True if the line has leaves or comments."""
- return bool(self.leaves or self.comments)
-
-
-@dataclass
-class EmptyLineTracker:
- """Provides a stateful method that returns the number of potential extra
- empty lines needed before and after the currently processed line.
-
- Note: this tracker works on lines that haven't been split yet. It assumes
- the prefix of the first leaf consists of optional newlines. Those newlines
- are consumed by `maybe_empty_lines()` and included in the computation.
- """
-
- is_pyi: bool = False
- previous_line: Optional[Line] = None
- previous_after: int = 0
- previous_defs: List[int] = Factory(list)
-
- def maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
- """Return the number of extra empty lines before and after the `current_line`.
-
- This is for separating `def`, `async def` and `class` with extra empty
- lines (two on module-level).
- """
- before, after = self._maybe_empty_lines(current_line)
- before = (
- # Black should not insert empty lines at the beginning
- # of the file
- 0
- if self.previous_line is None
- else before - self.previous_after
- )
- self.previous_after = after
- self.previous_line = current_line
- return before, after
-
- def _maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
- max_allowed = 1
- if current_line.depth == 0:
- max_allowed = 1 if self.is_pyi else 2
- if current_line.leaves:
- # Consume the first leaf's extra newlines.
- first_leaf = current_line.leaves[0]
- before = first_leaf.prefix.count("\n")
- before = min(before, max_allowed)
- first_leaf.prefix = ""
- else:
- before = 0
- depth = current_line.depth
- while self.previous_defs and self.previous_defs[-1] >= depth:
- self.previous_defs.pop()
- if self.is_pyi:
- before = 0 if depth else 1
- else:
- before = 1 if depth else 2
- if current_line.is_decorator or current_line.is_def or current_line.is_class:
- return self._maybe_empty_lines_for_class_or_def(current_line, before)
-
- if (
- self.previous_line
- and self.previous_line.is_import
- and not current_line.is_import
- and depth == self.previous_line.depth
- ):
- return (before or 1), 0
-
- if (
- self.previous_line
- and self.previous_line.is_class
- and current_line.is_triple_quoted_string
- ):
- return before, 1
-
- return before, 0
-
- def _maybe_empty_lines_for_class_or_def(
- self, current_line: Line, before: int
- ) -> Tuple[int, int]:
- if not current_line.is_decorator:
- self.previous_defs.append(current_line.depth)
- if self.previous_line is None:
- # Don't insert empty lines before the first line in the file.
- return 0, 0
-
- if self.previous_line.is_decorator:
- return 0, 0
-
- if self.previous_line.depth < current_line.depth and (
- self.previous_line.is_class or self.previous_line.is_def
- ):
- return 0, 0
-
- if (
- self.previous_line.is_comment
- and self.previous_line.depth == current_line.depth
- and before == 0
- ):
- return 0, 0
-
- if self.is_pyi:
- if self.previous_line.depth > current_line.depth:
- newlines = 1
- elif current_line.is_class or self.previous_line.is_class:
- if current_line.is_stub_class and self.previous_line.is_stub_class:
- # No blank line between classes with an empty body
- newlines = 0
- else:
- newlines = 1
- elif current_line.is_def and not self.previous_line.is_def:
- # Blank line between a block of functions and a block of non-functions
- newlines = 1
- else:
- newlines = 0
- else:
- newlines = 2
- if current_line.depth and newlines:
- newlines -= 1
- return newlines, 0
-
-
-@dataclass
-class LineGenerator(Visitor[Line]):
- """Generates reformatted Line objects. Empty lines are not emitted.
-
- Note: destroys the tree it's visiting by mutating prefixes of its leaves
- in ways that will no longer stringify to valid Python code on the tree.
- """
-
- is_pyi: bool = False
- normalize_strings: bool = True
- current_line: Line = Factory(Line)
- remove_u_prefix: bool = False
-
- def line(self, indent: int = 0) -> Iterator[Line]:
- """Generate a line.
-
- If the line is empty, only emit if it makes sense.
- If the line is too long, split it first and then generate.
-
- If any lines were generated, set up a new current_line.
- """
- if not self.current_line:
- self.current_line.depth += indent
- return # Line is empty, don't emit. Creating a new one unnecessary.
-
- complete_line = self.current_line
- self.current_line = Line(depth=complete_line.depth + indent)
- yield complete_line
-
- def visit_default(self, node: LN) -> Iterator[Line]:
- """Default `visit_*()` implementation. Recurses to children of `node`."""
- if isinstance(node, Leaf):
- any_open_brackets = self.current_line.bracket_tracker.any_open_brackets()
- for comment in generate_comments(node):
- if any_open_brackets:
- # any comment within brackets is subject to splitting
- self.current_line.append(comment)
- elif comment.type == token.COMMENT:
- # regular trailing comment
- self.current_line.append(comment)
- yield from self.line()
-
- else:
- # regular standalone comment
- yield from self.line()
-
- self.current_line.append(comment)
- yield from self.line()
-
- normalize_prefix(node, inside_brackets=any_open_brackets)
- if self.normalize_strings and node.type == token.STRING:
- normalize_string_prefix(node, remove_u_prefix=self.remove_u_prefix)
- normalize_string_quotes(node)
- if node.type == token.NUMBER:
- normalize_numeric_literal(node)
- if node.type not in WHITESPACE:
- self.current_line.append(node)
- yield from super().visit_default(node)
-
- def visit_atom(self, node: Node) -> Iterator[Line]:
- # Always make parentheses invisible around a single node, because it should
- # not be needed (except in the case of yield, where removing the parentheses
- # produces a SyntaxError).
- if (
- len(node.children) == 3
- and isinstance(node.children[0], Leaf)
- and node.children[0].type == token.LPAR
- and isinstance(node.children[2], Leaf)
- and node.children[2].type == token.RPAR
- and isinstance(node.children[1], Leaf)
- and not (
- node.children[1].type == token.NAME
- and node.children[1].value == "yield"
- )
- ):
- node.children[0].value = ""
- node.children[2].value = ""
- yield from super().visit_default(node)
-
- def visit_factor(self, node: Node) -> Iterator[Line]:
- """Force parentheses between a unary op and a binary power:
-
- -2 ** 8 -> -(2 ** 8)
- """
- child = node.children[1]
- if child.type == syms.power and len(child.children) == 3:
- lpar = Leaf(token.LPAR, "(")
- rpar = Leaf(token.RPAR, ")")
- index = child.remove() or 0
- node.insert_child(index, Node(syms.atom, [lpar, child, rpar]))
- yield from self.visit_default(node)
-
- def visit_INDENT(self, node: Node) -> Iterator[Line]:
- """Increase indentation level, maybe yield a line."""
- # In blib2to3 INDENT never holds comments.
- yield from self.line(+1)
- yield from self.visit_default(node)
-
- def visit_DEDENT(self, node: Node) -> Iterator[Line]:
- """Decrease indentation level, maybe yield a line."""
- # The current line might still wait for trailing comments. At DEDENT time
- # there won't be any (they would be prefixes on the preceding NEWLINE).
- # Emit the line then.
- yield from self.line()
-
- # While DEDENT has no value, its prefix may contain standalone comments
- # that belong to the current indentation level. Get 'em.
- yield from self.visit_default(node)
-
- # Finally, emit the dedent.
- yield from self.line(-1)
-
- def visit_stmt(
- self, node: Node, keywords: Set[str], parens: Set[str]
- ) -> Iterator[Line]:
- """Visit a statement.
-
- This implementation is shared for `if`, `while`, `for`, `try`, `except`,
- `def`, `with`, `class`, `assert` and assignments.
-
- The relevant Python language `keywords` for a given statement will be
- NAME leaves within it. This methods puts those on a separate line.
-
- `parens` holds a set of string leaf values immediately after which
- invisible parens should be put.
- """
- normalize_invisible_parens(node, parens_after=parens)
- for child in node.children:
- if child.type == token.NAME and child.value in keywords: # type: ignore
- yield from self.line()
-
- yield from self.visit(child)
-
- def visit_suite(self, node: Node) -> Iterator[Line]:
- """Visit a suite."""
- if self.is_pyi and is_stub_suite(node):
- yield from self.visit(node.children[2])
- else:
- yield from self.visit_default(node)
-
- def visit_simple_stmt(self, node: Node) -> Iterator[Line]:
- """Visit a statement without nested statements."""
- is_suite_like = node.parent and node.parent.type in STATEMENT
- if is_suite_like:
- if self.is_pyi and is_stub_body(node):
- yield from self.visit_default(node)
- else:
- yield from self.line(+1)
- yield from self.visit_default(node)
- yield from self.line(-1)
-
- else:
- if not self.is_pyi or not node.parent or not is_stub_suite(node.parent):
- yield from self.line()
- yield from self.visit_default(node)
-
- def visit_async_stmt(self, node: Node) -> Iterator[Line]:
- """Visit `async def`, `async for`, `async with`."""
- yield from self.line()
-
- children = iter(node.children)
- for child in children:
- yield from self.visit(child)
-
- if child.type == token.ASYNC:
- break
-
- internal_stmt = next(children)
- for child in internal_stmt.children:
- yield from self.visit(child)
-
- def visit_decorators(self, node: Node) -> Iterator[Line]:
- """Visit decorators."""
- for child in node.children:
- yield from self.line()
- yield from self.visit(child)
-
- def visit_SEMI(self, leaf: Leaf) -> Iterator[Line]:
- """Remove a semicolon and put the other statement on a separate line."""
- yield from self.line()
-
- def visit_ENDMARKER(self, leaf: Leaf) -> Iterator[Line]:
- """End of file. Process outstanding comments and end with a newline."""
- yield from self.visit_default(leaf)
- yield from self.line()
-
- def visit_STANDALONE_COMMENT(self, leaf: Leaf) -> Iterator[Line]:
- if not self.current_line.bracket_tracker.any_open_brackets():
- yield from self.line()
- yield from self.visit_default(leaf)
-
- def __attrs_post_init__(self) -> None:
- """You are in a twisty little maze of passages."""
- v = self.visit_stmt
- Ø: Set[str] = set()
- self.visit_assert_stmt = partial(v, keywords={"assert"}, parens={"assert", ","})
- self.visit_if_stmt = partial(
- v, keywords={"if", "else", "elif"}, parens={"if", "elif"}
- )
- self.visit_while_stmt = partial(v, keywords={"while", "else"}, parens={"while"})
- self.visit_for_stmt = partial(v, keywords={"for", "else"}, parens={"for", "in"})
- self.visit_try_stmt = partial(
- v, keywords={"try", "except", "else", "finally"}, parens=Ø
- )
- self.visit_except_clause = partial(v, keywords={"except"}, parens=Ø)
- self.visit_with_stmt = partial(v, keywords={"with"}, parens=Ø)
- self.visit_funcdef = partial(v, keywords={"def"}, parens=Ø)
- self.visit_classdef = partial(v, keywords={"class"}, parens=Ø)
- self.visit_expr_stmt = partial(v, keywords=Ø, parens=ASSIGNMENTS)
- self.visit_return_stmt = partial(v, keywords={"return"}, parens={"return"})
- self.visit_import_from = partial(v, keywords=Ø, parens={"import"})
- self.visit_del_stmt = partial(v, keywords=Ø, parens={"del"})
- self.visit_async_funcdef = self.visit_async_stmt
- self.visit_decorated = self.visit_decorators
-
-
-IMPLICIT_TUPLE = {syms.testlist, syms.testlist_star_expr, syms.exprlist}
-BRACKET = {token.LPAR: token.RPAR, token.LSQB: token.RSQB, token.LBRACE: token.RBRACE}
-OPENING_BRACKETS = set(BRACKET.keys())
-CLOSING_BRACKETS = set(BRACKET.values())
-BRACKETS = OPENING_BRACKETS | CLOSING_BRACKETS
-ALWAYS_NO_SPACE = CLOSING_BRACKETS | {token.COMMA, STANDALONE_COMMENT}
-
-
-def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str: # noqa: C901
- """Return whitespace prefix if needed for the given `leaf`.
-
- `complex_subscript` signals whether the given leaf is part of a subscription
- which has non-trivial arguments, like arithmetic expressions or function calls.
- """
- NO = ""
- SPACE = " "
- DOUBLESPACE = " "
- t = leaf.type
- p = leaf.parent
- v = leaf.value
- if t in ALWAYS_NO_SPACE:
- return NO
-
- if t == token.COMMENT:
- return DOUBLESPACE
-
- assert p is not None, f"INTERNAL ERROR: hand-made leaf without parent: {leaf!r}"
- if t == token.COLON and p.type not in {
- syms.subscript,
- syms.subscriptlist,
- syms.sliceop,
- }:
- return NO
-
- prev = leaf.prev_sibling
- if not prev:
- prevp = preceding_leaf(p)
- if not prevp or prevp.type in OPENING_BRACKETS:
- return NO
-
- if t == token.COLON:
- if prevp.type == token.COLON:
- return NO
-
- elif prevp.type != token.COMMA and not complex_subscript:
- return NO
-
- return SPACE
-
- if prevp.type == token.EQUAL:
- if prevp.parent:
- if prevp.parent.type in {
- syms.arglist,
- syms.argument,
- syms.parameters,
- syms.varargslist,
- }:
- return NO
-
- elif prevp.parent.type == syms.typedargslist:
- # A bit hacky: if the equal sign has whitespace, it means we
- # previously found it's a typed argument. So, we're using
- # that, too.
- return prevp.prefix
-
- elif prevp.type in VARARGS_SPECIALS:
- if is_vararg(prevp, within=VARARGS_PARENTS | UNPACKING_PARENTS):
- return NO
-
- elif prevp.type == token.COLON:
- if prevp.parent and prevp.parent.type in {syms.subscript, syms.sliceop}:
- return SPACE if complex_subscript else NO
-
- elif (
- prevp.parent
- and prevp.parent.type == syms.factor
- and prevp.type in MATH_OPERATORS
- ):
- return NO
-
- elif (
- prevp.type == token.RIGHTSHIFT
- and prevp.parent
- and prevp.parent.type == syms.shift_expr
- and prevp.prev_sibling
- and prevp.prev_sibling.type == token.NAME
- and prevp.prev_sibling.value == "print" # type: ignore
- ):
- # Python 2 print chevron
- return NO
-
- elif prev.type in OPENING_BRACKETS:
- return NO
-
- if p.type in {syms.parameters, syms.arglist}:
- # untyped function signatures or calls
- if not prev or prev.type != token.COMMA:
- return NO
-
- elif p.type == syms.varargslist:
- # lambdas
- if prev and prev.type != token.COMMA:
- return NO
-
- elif p.type == syms.typedargslist:
- # typed function signatures
- if not prev:
- return NO
-
- if t == token.EQUAL:
- if prev.type != syms.tname:
- return NO
-
- elif prev.type == token.EQUAL:
- # A bit hacky: if the equal sign has whitespace, it means we
- # previously found it's a typed argument. So, we're using that, too.
- return prev.prefix
-
- elif prev.type != token.COMMA:
- return NO
-
- elif p.type == syms.tname:
- # type names
- if not prev:
- prevp = preceding_leaf(p)
- if not prevp or prevp.type != token.COMMA:
- return NO
-
- elif p.type == syms.trailer:
- # attributes and calls
- if t == token.LPAR or t == token.RPAR:
- return NO
-
- if not prev:
- if t == token.DOT:
- prevp = preceding_leaf(p)
- if not prevp or prevp.type != token.NUMBER:
- return NO
-
- elif t == token.LSQB:
- return NO
-
- elif prev.type != token.COMMA:
- return NO
-
- elif p.type == syms.argument:
- # single argument
- if t == token.EQUAL:
- return NO
-
- if not prev:
- prevp = preceding_leaf(p)
- if not prevp or prevp.type == token.LPAR:
- return NO
-
- elif prev.type in {token.EQUAL} | VARARGS_SPECIALS:
- return NO
-
- elif p.type == syms.decorator:
- # decorators
- return NO
-
- elif p.type == syms.dotted_name:
- if prev:
- return NO
-
- prevp = preceding_leaf(p)
- if not prevp or prevp.type == token.AT or prevp.type == token.DOT:
- return NO
-
- elif p.type == syms.classdef:
- if t == token.LPAR:
- return NO
-
- if prev and prev.type == token.LPAR:
- return NO
-
- elif p.type in {syms.subscript, syms.sliceop}:
- # indexing
- if not prev:
- assert p.parent is not None, "subscripts are always parented"
- if p.parent.type == syms.subscriptlist:
- return SPACE
-
- return NO
-
- elif not complex_subscript:
- return NO
-
- elif p.type == syms.atom:
- if prev and t == token.DOT:
- # dots, but not the first one.
- return NO
-
- elif p.type == syms.dictsetmaker:
- # dict unpacking
- if prev and prev.type == token.DOUBLESTAR:
- return NO
-
- elif p.type in {syms.factor, syms.star_expr}:
- # unary ops
- if not prev:
- prevp = preceding_leaf(p)
- if not prevp or prevp.type in OPENING_BRACKETS:
- return NO
-
- prevp_parent = prevp.parent
- assert prevp_parent is not None
- if prevp.type == token.COLON and prevp_parent.type in {
- syms.subscript,
- syms.sliceop,
- }:
- return NO
-
- elif prevp.type == token.EQUAL and prevp_parent.type == syms.argument:
- return NO
-
- elif t in {token.NAME, token.NUMBER, token.STRING}:
- return NO
-
- elif p.type == syms.import_from:
- if t == token.DOT:
- if prev and prev.type == token.DOT:
- return NO
-
- elif t == token.NAME:
- if v == "import":
- return SPACE
-
- if prev and prev.type == token.DOT:
- return NO
-
- elif p.type == syms.sliceop:
- return NO
-
- return SPACE
-
-
-def preceding_leaf(node: Optional[LN]) -> Optional[Leaf]:
- """Return the first leaf that precedes `node`, if any."""
- while node:
- res = node.prev_sibling
- if res:
- if isinstance(res, Leaf):
- return res
-
- try:
- return list(res.leaves())[-1]
-
- except IndexError:
- return None
-
- node = node.parent
- return None
-
-
-def child_towards(ancestor: Node, descendant: LN) -> Optional[LN]:
- """Return the child of `ancestor` that contains `descendant`."""
- node: Optional[LN] = descendant
- while node and node.parent != ancestor:
- node = node.parent
- return node
-
-
-def container_of(leaf: Leaf) -> LN:
- """Return `leaf` or one of its ancestors that is the topmost container of it.
-
- By "container" we mean a node where `leaf` is the very first child.
- """
- same_prefix = leaf.prefix
- container: LN = leaf
- while container:
- parent = container.parent
- if parent is None:
- break
-
- if parent.children[0].prefix != same_prefix:
- break
-
- if parent.type == syms.file_input:
- break
-
- if parent.prev_sibling is not None and parent.prev_sibling.type in BRACKETS:
- break
-
- container = parent
- return container
-
-
-def is_split_after_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> Priority:
- """Return the priority of the `leaf` delimiter, given a line break after it.
-
- The delimiter priorities returned here are from those delimiters that would
- cause a line break after themselves.
-
- Higher numbers are higher priority.
- """
- if leaf.type == token.COMMA:
- return COMMA_PRIORITY
-
- return 0
-
-
-def is_split_before_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> Priority:
- """Return the priority of the `leaf` delimiter, given a line break before it.
-
- The delimiter priorities returned here are from those delimiters that would
- cause a line break before themselves.
-
- Higher numbers are higher priority.
- """
- if is_vararg(leaf, within=VARARGS_PARENTS | UNPACKING_PARENTS):
- # * and ** might also be MATH_OPERATORS but in this case they are not.
- # Don't treat them as a delimiter.
- return 0
-
- if (
- leaf.type == token.DOT
- and leaf.parent
- and leaf.parent.type not in {syms.import_from, syms.dotted_name}
- and (previous is None or previous.type in CLOSING_BRACKETS)
- ):
- return DOT_PRIORITY
-
- if (
- leaf.type in MATH_OPERATORS
- and leaf.parent
- and leaf.parent.type not in {syms.factor, syms.star_expr}
- ):
- return MATH_PRIORITIES[leaf.type]
-
- if leaf.type in COMPARATORS:
- return COMPARATOR_PRIORITY
-
- if (
- leaf.type == token.STRING
- and previous is not None
- and previous.type == token.STRING
- ):
- return STRING_PRIORITY
-
- if leaf.type not in {token.NAME, token.ASYNC}:
- return 0
-
- if (
- leaf.value == "for"
- and leaf.parent
- and leaf.parent.type in {syms.comp_for, syms.old_comp_for}
- or leaf.type == token.ASYNC
- ):
- if (
- not isinstance(leaf.prev_sibling, Leaf)
- or leaf.prev_sibling.value != "async"
- ):
- return COMPREHENSION_PRIORITY
-
- if (
- leaf.value == "if"
- and leaf.parent
- and leaf.parent.type in {syms.comp_if, syms.old_comp_if}
- ):
- return COMPREHENSION_PRIORITY
-
- if leaf.value in {"if", "else"} and leaf.parent and leaf.parent.type == syms.test:
- return TERNARY_PRIORITY
-
- if leaf.value == "is":
- return COMPARATOR_PRIORITY
-
- if (
- leaf.value == "in"
- and leaf.parent
- and leaf.parent.type in {syms.comp_op, syms.comparison}
- and not (
- previous is not None
- and previous.type == token.NAME
- and previous.value == "not"
- )
- ):
- return COMPARATOR_PRIORITY
-
- if (
- leaf.value == "not"
- and leaf.parent
- and leaf.parent.type == syms.comp_op
- and not (
- previous is not None
- and previous.type == token.NAME
- and previous.value == "is"
- )
- ):
- return COMPARATOR_PRIORITY
-
- if leaf.value in LOGIC_OPERATORS and leaf.parent:
- return LOGIC_PRIORITY
-
- return 0
-
-
-FMT_OFF = {"# fmt: off", "# fmt:off", "# yapf: disable"}
-FMT_ON = {"# fmt: on", "# fmt:on", "# yapf: enable"}
-
-
-def generate_comments(leaf: LN) -> Iterator[Leaf]:
- """Clean the prefix of the `leaf` and generate comments from it, if any.
-
- Comments in lib2to3 are shoved into the whitespace prefix. This happens
- in `pgen2/driver.py:Driver.parse_tokens()`. This was a brilliant implementation
- move because it does away with modifying the grammar to include all the
- possible places in which comments can be placed.
-
- The sad consequence for us though is that comments don't "belong" anywhere.
- This is why this function generates simple parentless Leaf objects for
- comments. We simply don't know what the correct parent should be.
-
- No matter though, we can live without this. We really only need to
- differentiate between inline and standalone comments. The latter don't
- share the line with any code.
-
- Inline comments are emitted as regular token.COMMENT leaves. Standalone
- are emitted with a fake STANDALONE_COMMENT token identifier.
- """
- for pc in list_comments(leaf.prefix, is_endmarker=leaf.type == token.ENDMARKER):
- yield Leaf(pc.type, pc.value, prefix="\n" * pc.newlines)
-
-
-@dataclass
-class ProtoComment:
- """Describes a piece of syntax that is a comment.
-
- It's not a :class:`blib2to3.pytree.Leaf` so that:
-
- * it can be cached (`Leaf` objects should not be reused more than once as
- they store their lineno, column, prefix, and parent information);
- * `newlines` and `consumed` fields are kept separate from the `value`. This
- simplifies handling of special marker comments like ``# fmt: off/on``.
- """
-
- type: int # token.COMMENT or STANDALONE_COMMENT
- value: str # content of the comment
- newlines: int # how many newlines before the comment
- consumed: int # how many characters of the original leaf's prefix did we consume
-
-
-@lru_cache(maxsize=4096)
-def list_comments(prefix: str, *, is_endmarker: bool) -> List[ProtoComment]:
- """Return a list of :class:`ProtoComment` objects parsed from the given `prefix`."""
- result: List[ProtoComment] = []
- if not prefix or "#" not in prefix:
- return result
-
- consumed = 0
- nlines = 0
- ignored_lines = 0
- for index, line in enumerate(prefix.split("\n")):
- consumed += len(line) + 1 # adding the length of the split '\n'
- line = line.lstrip()
- if not line:
- nlines += 1
- if not line.startswith("#"):
- # Escaped newlines outside of a comment are not really newlines at
- # all. We treat a single-line comment following an escaped newline
- # as a simple trailing comment.
- if line.endswith("\\"):
- ignored_lines += 1
- continue
-
- if index == ignored_lines and not is_endmarker:
- comment_type = token.COMMENT # simple trailing comment
- else:
- comment_type = STANDALONE_COMMENT
- comment = make_comment(line)
- result.append(
- ProtoComment(
- type=comment_type, value=comment, newlines=nlines, consumed=consumed
- )
- )
- nlines = 0
- return result
-
-
-def make_comment(content: str) -> str:
- """Return a consistently formatted comment from the given `content` string.
-
- All comments (except for "##", "#!", "#:", '#'", "#%%") should have a single
- space between the hash sign and the content.
-
- If `content` didn't start with a hash sign, one is provided.
- """
- content = content.rstrip()
- if not content:
- return "#"
-
- if content[0] == "#":
- content = content[1:]
- if content and content[0] not in " !:#'%":
- content = " " + content
- return "#" + content
-
-
-def split_line(
- line: Line,
- line_length: int,
- inner: bool = False,
- features: Collection[Feature] = (),
-) -> Iterator[Line]:
- """Split a `line` into potentially many lines.
-
- They should fit in the allotted `line_length` but might not be able to.
- `inner` signifies that there were a pair of brackets somewhere around the
- current `line`, possibly transitively. This means we can fallback to splitting
- by delimiters if the LHS/RHS don't yield any results.
-
- `features` are syntactical features that may be used in the output.
- """
- if line.is_comment:
- yield line
- return
-
- line_str = str(line).strip("\n")
-
- if (
- not line.contains_uncollapsable_type_comments()
- and not line.should_explode
- and not line.is_collection_with_optional_trailing_comma
- and (
- is_line_short_enough(line, line_length=line_length, line_str=line_str)
- or line.contains_unsplittable_type_ignore()
- )
- ):
- yield line
- return
-
- split_funcs: List[SplitFunc]
- if line.is_def:
- split_funcs = [left_hand_split]
- else:
-
- def rhs(line: Line, features: Collection[Feature]) -> Iterator[Line]:
- for omit in generate_trailers_to_omit(line, line_length):
- lines = list(right_hand_split(line, line_length, features, omit=omit))
- if is_line_short_enough(lines[0], line_length=line_length):
- yield from lines
- return
-
- # All splits failed, best effort split with no omits.
- # This mostly happens to multiline strings that are by definition
- # reported as not fitting a single line.
- yield from right_hand_split(line, line_length, features=features)
-
- if line.inside_brackets:
- split_funcs = [delimiter_split, standalone_comment_split, rhs]
- else:
- split_funcs = [rhs]
- for split_func in split_funcs:
- # We are accumulating lines in `result` because we might want to abort
- # mission and return the original line in the end, or attempt a different
- # split altogether.
- result: List[Line] = []
- try:
- for l in split_func(line, features):
- if str(l).strip("\n") == line_str:
- raise CannotSplit("Split function returned an unchanged result")
-
- result.extend(
- split_line(
- l, line_length=line_length, inner=True, features=features
- )
- )
- except CannotSplit:
- continue
-
- else:
- yield from result
- break
-
- else:
- yield line
-
-
-def left_hand_split(line: Line, features: Collection[Feature] = ()) -> Iterator[Line]:
- """Split line into many lines, starting with the first matching bracket pair.
-
- Note: this usually looks weird, only use this for function definitions.
- Prefer RHS otherwise. This is why this function is not symmetrical with
- :func:`right_hand_split` which also handles optional parentheses.
- """
- tail_leaves: List[Leaf] = []
- body_leaves: List[Leaf] = []
- head_leaves: List[Leaf] = []
- current_leaves = head_leaves
- matching_bracket = None
- for leaf in line.leaves:
- if (
- current_leaves is body_leaves
- and leaf.type in CLOSING_BRACKETS
- and leaf.opening_bracket is matching_bracket
- ):
- current_leaves = tail_leaves if body_leaves else head_leaves
- current_leaves.append(leaf)
- if current_leaves is head_leaves:
- if leaf.type in OPENING_BRACKETS:
- matching_bracket = leaf
- current_leaves = body_leaves
- if not matching_bracket:
- raise CannotSplit("No brackets found")
-
- head = bracket_split_build_line(head_leaves, line, matching_bracket)
- body = bracket_split_build_line(body_leaves, line, matching_bracket, is_body=True)
- tail = bracket_split_build_line(tail_leaves, line, matching_bracket)
- bracket_split_succeeded_or_raise(head, body, tail)
- for result in (head, body, tail):
- if result:
- yield result
-
-
-def right_hand_split(
- line: Line,
- line_length: int,
- features: Collection[Feature] = (),
- omit: Collection[LeafID] = (),
-) -> Iterator[Line]:
- """Split line into many lines, starting with the last matching bracket pair.
-
- If the split was by optional parentheses, attempt splitting without them, too.
- `omit` is a collection of closing bracket IDs that shouldn't be considered for
- this split.
-
- Note: running this function modifies `bracket_depth` on the leaves of `line`.
- """
- tail_leaves: List[Leaf] = []
- body_leaves: List[Leaf] = []
- head_leaves: List[Leaf] = []
- current_leaves = tail_leaves
- opening_bracket = None
- closing_bracket = None
- for leaf in reversed(line.leaves):
- if current_leaves is body_leaves:
- if leaf is opening_bracket:
- current_leaves = head_leaves if body_leaves else tail_leaves
- current_leaves.append(leaf)
- if current_leaves is tail_leaves:
- if leaf.type in CLOSING_BRACKETS and id(leaf) not in omit:
- opening_bracket = leaf.opening_bracket
- closing_bracket = leaf
- current_leaves = body_leaves
- if not (opening_bracket and closing_bracket and head_leaves):
- # If there is no opening or closing_bracket that means the split failed and
- # all content is in the tail. Otherwise, if `head_leaves` are empty, it means
- # the matching `opening_bracket` wasn't available on `line` anymore.
- raise CannotSplit("No brackets found")
-
- tail_leaves.reverse()
- body_leaves.reverse()
- head_leaves.reverse()
- head = bracket_split_build_line(head_leaves, line, opening_bracket)
- body = bracket_split_build_line(body_leaves, line, opening_bracket, is_body=True)
- tail = bracket_split_build_line(tail_leaves, line, opening_bracket)
- bracket_split_succeeded_or_raise(head, body, tail)
- if (
- # the body shouldn't be exploded
- not body.should_explode
- # the opening bracket is an optional paren
- and opening_bracket.type == token.LPAR
- and not opening_bracket.value
- # the closing bracket is an optional paren
- and closing_bracket.type == token.RPAR
- and not closing_bracket.value
- # it's not an import (optional parens are the only thing we can split on
- # in this case; attempting a split without them is a waste of time)
- and not line.is_import
- # there are no standalone comments in the body
- and not body.contains_standalone_comments(0)
- # and we can actually remove the parens
- and can_omit_invisible_parens(body, line_length)
- ):
- omit = {id(closing_bracket), *omit}
- try:
- yield from right_hand_split(line, line_length, features=features, omit=omit)
- return
-
- except CannotSplit:
- if not (
- can_be_split(body)
- or is_line_short_enough(body, line_length=line_length)
- ):
- raise CannotSplit(
- "Splitting failed, body is still too long and can't be split."
- )
-
- elif head.contains_multiline_strings() or tail.contains_multiline_strings():
- raise CannotSplit(
- "The current optional pair of parentheses is bound to fail to "
- "satisfy the splitting algorithm because the head or the tail "
- "contains multiline strings which by definition never fit one "
- "line."
- )
-
- ensure_visible(opening_bracket)
- ensure_visible(closing_bracket)
- for result in (head, body, tail):
- if result:
- yield result
-
-
-def bracket_split_succeeded_or_raise(head: Line, body: Line, tail: Line) -> None:
- """Raise :exc:`CannotSplit` if the last left- or right-hand split failed.
-
- Do nothing otherwise.
-
- A left- or right-hand split is based on a pair of brackets. Content before
- (and including) the opening bracket is left on one line, content inside the
- brackets is put on a separate line, and finally content starting with and
- following the closing bracket is put on a separate line.
-
- Those are called `head`, `body`, and `tail`, respectively. If the split
- produced the same line (all content in `head`) or ended up with an empty `body`
- and the `tail` is just the closing bracket, then it's considered failed.
- """
- tail_len = len(str(tail).strip())
- if not body:
- if tail_len == 0:
- raise CannotSplit("Splitting brackets produced the same line")
-
- elif tail_len < 3:
- raise CannotSplit(
- f"Splitting brackets on an empty body to save "
- f"{tail_len} characters is not worth it"
- )
-
-
-def bracket_split_build_line(
- leaves: List[Leaf], original: Line, opening_bracket: Leaf, *, is_body: bool = False
-) -> Line:
- """Return a new line with given `leaves` and respective comments from `original`.
-
- If `is_body` is True, the result line is one-indented inside brackets and as such
- has its first leaf's prefix normalized and a trailing comma added when expected.
- """
- result = Line(depth=original.depth)
- if is_body:
- result.inside_brackets = True
- result.depth += 1
- if leaves:
- # Since body is a new indent level, remove spurious leading whitespace.
- normalize_prefix(leaves[0], inside_brackets=True)
- # Ensure a trailing comma for imports and standalone function arguments, but
- # be careful not to add one after any comments.
- no_commas = original.is_def and not any(
- l.type == token.COMMA for l in leaves
- )
-
- if original.is_import or no_commas:
- for i in range(len(leaves) - 1, -1, -1):
- if leaves[i].type == STANDALONE_COMMENT:
- continue
- elif leaves[i].type == token.COMMA:
- break
- else:
- leaves.insert(i + 1, Leaf(token.COMMA, ","))
- break
- # Populate the line
- for leaf in leaves:
- result.append(leaf, preformatted=True)
- for comment_after in original.comments_after(leaf):
- result.append(comment_after, preformatted=True)
- if is_body:
- result.should_explode = should_explode(result, opening_bracket)
- return result
-
-
-def dont_increase_indentation(split_func: SplitFunc) -> SplitFunc:
- """Normalize prefix of the first leaf in every line returned by `split_func`.
-
- This is a decorator over relevant split functions.
- """
-
- @wraps(split_func)
- def split_wrapper(line: Line, features: Collection[Feature] = ()) -> Iterator[Line]:
- for l in split_func(line, features):
- normalize_prefix(l.leaves[0], inside_brackets=True)
- yield l
-
- return split_wrapper
-
-
-@dont_increase_indentation
-def delimiter_split(line: Line, features: Collection[Feature] = ()) -> Iterator[Line]:
- """Split according to delimiters of the highest priority.
-
- If the appropriate Features are given, the split will add trailing commas
- also in function signatures and calls that contain `*` and `**`.
- """
- try:
- last_leaf = line.leaves[-1]
- except IndexError:
- raise CannotSplit("Line empty")
-
- bt = line.bracket_tracker
- try:
- delimiter_priority = bt.max_delimiter_priority(exclude={id(last_leaf)})
- except ValueError:
- raise CannotSplit("No delimiters found")
-
- if delimiter_priority == DOT_PRIORITY:
- if bt.delimiter_count_with_priority(delimiter_priority) == 1:
- raise CannotSplit("Splitting a single attribute from its owner looks wrong")
-
- current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
- lowest_depth = sys.maxsize
- trailing_comma_safe = True
-
- def append_to_line(leaf: Leaf) -> Iterator[Line]:
- """Append `leaf` to current line or to new line if appending impossible."""
- nonlocal current_line
- try:
- current_line.append_safe(leaf, preformatted=True)
- except ValueError:
- yield current_line
-
- current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
- current_line.append(leaf)
-
- for leaf in line.leaves:
- yield from append_to_line(leaf)
-
- for comment_after in line.comments_after(leaf):
- yield from append_to_line(comment_after)
-
- lowest_depth = min(lowest_depth, leaf.bracket_depth)
- if leaf.bracket_depth == lowest_depth:
- if is_vararg(leaf, within={syms.typedargslist}):
- trailing_comma_safe = (
- trailing_comma_safe and Feature.TRAILING_COMMA_IN_DEF in features
- )
- elif is_vararg(leaf, within={syms.arglist, syms.argument}):
- trailing_comma_safe = (
- trailing_comma_safe and Feature.TRAILING_COMMA_IN_CALL in features
- )
-
- leaf_priority = bt.delimiters.get(id(leaf))
- if leaf_priority == delimiter_priority:
- yield current_line
-
- current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
- if current_line:
- if (
- trailing_comma_safe
- and delimiter_priority == COMMA_PRIORITY
- and current_line.leaves[-1].type != token.COMMA
- and current_line.leaves[-1].type != STANDALONE_COMMENT
- ):
- current_line.append(Leaf(token.COMMA, ","))
- yield current_line
-
-
-@dont_increase_indentation
-def standalone_comment_split(
- line: Line, features: Collection[Feature] = ()
-) -> Iterator[Line]:
- """Split standalone comments from the rest of the line."""
- if not line.contains_standalone_comments(0):
- raise CannotSplit("Line does not have any standalone comments")
-
- current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
-
- def append_to_line(leaf: Leaf) -> Iterator[Line]:
- """Append `leaf` to current line or to new line if appending impossible."""
- nonlocal current_line
- try:
- current_line.append_safe(leaf, preformatted=True)
- except ValueError:
- yield current_line
-
- current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
- current_line.append(leaf)
-
- for leaf in line.leaves:
- yield from append_to_line(leaf)
-
- for comment_after in line.comments_after(leaf):
- yield from append_to_line(comment_after)
-
- if current_line:
- yield current_line
-
-
-def is_import(leaf: Leaf) -> bool:
- """Return True if the given leaf starts an import statement."""
- p = leaf.parent
- t = leaf.type
- v = leaf.value
- return bool(
- t == token.NAME
- and (
- (v == "import" and p and p.type == syms.import_name)
- or (v == "from" and p and p.type == syms.import_from)
- )
- )
-
-
-def is_type_comment(leaf: Leaf, suffix: str = "") -> bool:
- """Return True if the given leaf is a special comment.
- Only returns true for type comments for now."""
- t = leaf.type
- v = leaf.value
- return t in {token.COMMENT, t == STANDALONE_COMMENT} and v.startswith(
- "# type:" + suffix
- )
-
-
-def normalize_prefix(leaf: Leaf, *, inside_brackets: bool) -> None:
- """Leave existing extra newlines if not `inside_brackets`. Remove everything
- else.
-
- Note: don't use backslashes for formatting or you'll lose your voting rights.
- """
- if not inside_brackets:
- spl = leaf.prefix.split("#")
- if "\\" not in spl[0]:
- nl_count = spl[-1].count("\n")
- if len(spl) > 1:
- nl_count -= 1
- leaf.prefix = "\n" * nl_count
- return
-
- leaf.prefix = ""
-
-
-def normalize_string_prefix(leaf: Leaf, remove_u_prefix: bool = False) -> None:
- """Make all string prefixes lowercase.
-
- If remove_u_prefix is given, also removes any u prefix from the string.
-
- Note: Mutates its argument.
- """
- match = re.match(r"^([furbFURB]*)(.*)$", leaf.value, re.DOTALL)
- assert match is not None, f"failed to match string {leaf.value!r}"
- orig_prefix = match.group(1)
- new_prefix = orig_prefix.lower()
- if remove_u_prefix:
- new_prefix = new_prefix.replace("u", "")
- leaf.value = f"{new_prefix}{match.group(2)}"
-
-
-def normalize_string_quotes(leaf: Leaf) -> None:
- """Prefer double quotes but only if it doesn't cause more escaping.
-
- Adds or removes backslashes as appropriate. Doesn't parse and fix
- strings nested in f-strings (yet).
-
- Note: Mutates its argument.
- """
- value = leaf.value.lstrip("furbFURB")
- if value[:3] == '"""':
- return
-
- elif value[:3] == "'''":
- orig_quote = "'''"
- new_quote = '"""'
- elif value[0] == '"':
- orig_quote = '"'
- new_quote = "'"
- else:
- orig_quote = "'"
- new_quote = '"'
- first_quote_pos = leaf.value.find(orig_quote)
- if first_quote_pos == -1:
- return # There's an internal error
-
- prefix = leaf.value[:first_quote_pos]
- unescaped_new_quote = re.compile(rf"(([^\\]|^)(\\\\)*){new_quote}")
- escaped_new_quote = re.compile(rf"([^\\]|^)\\((?:\\\\)*){new_quote}")
- escaped_orig_quote = re.compile(rf"([^\\]|^)\\((?:\\\\)*){orig_quote}")
- body = leaf.value[first_quote_pos + len(orig_quote) : -len(orig_quote)]
- if "r" in prefix.casefold():
- if unescaped_new_quote.search(body):
- # There's at least one unescaped new_quote in this raw string
- # so converting is impossible
- return
-
- # Do not introduce or remove backslashes in raw strings
- new_body = body
- else:
- # remove unnecessary escapes
- new_body = sub_twice(escaped_new_quote, rf"\1\2{new_quote}", body)
- if body != new_body:
- # Consider the string without unnecessary escapes as the original
- body = new_body
- leaf.value = f"{prefix}{orig_quote}{body}{orig_quote}"
- new_body = sub_twice(escaped_orig_quote, rf"\1\2{orig_quote}", new_body)
- new_body = sub_twice(unescaped_new_quote, rf"\1\\{new_quote}", new_body)
- if "f" in prefix.casefold():
- matches = re.findall(
- r"""
- (?:[^{]|^)\{ # start of the string or a non-{ followed by a single {
- ([^{].*?) # contents of the brackets except if begins with {{
- \}(?:[^}]|$) # A } followed by end of the string or a non-}
- """,
- new_body,
- re.VERBOSE,
- )
- for m in matches:
- if "\\" in str(m):
- # Do not introduce backslashes in interpolated expressions
- return
- if new_quote == '"""' and new_body[-1:] == '"':
- # edge case:
- new_body = new_body[:-1] + '\\"'
- orig_escape_count = body.count("\\")
- new_escape_count = new_body.count("\\")
- if new_escape_count > orig_escape_count:
- return # Do not introduce more escaping
-
- if new_escape_count == orig_escape_count and orig_quote == '"':
- return # Prefer double quotes
-
- leaf.value = f"{prefix}{new_quote}{new_body}{new_quote}"
-
-
-def normalize_numeric_literal(leaf: Leaf) -> None:
- """Normalizes numeric (float, int, and complex) literals.
-
- All letters used in the representation are normalized to lowercase (except
- in Python 2 long literals).
- """
- text = leaf.value.lower()
- if text.startswith(("0o", "0b")):
- # Leave octal and binary literals alone.
- pass
- elif text.startswith("0x"):
- # Change hex literals to upper case.
- before, after = text[:2], text[2:]
- text = f"{before}{after.upper()}"
- elif "e" in text:
- before, after = text.split("e")
- sign = ""
- if after.startswith("-"):
- after = after[1:]
- sign = "-"
- elif after.startswith("+"):
- after = after[1:]
- before = format_float_or_int_string(before)
- text = f"{before}e{sign}{after}"
- elif text.endswith(("j", "l")):
- number = text[:-1]
- suffix = text[-1]
- # Capitalize in "2L" because "l" looks too similar to "1".
- if suffix == "l":
- suffix = "L"
- text = f"{format_float_or_int_string(number)}{suffix}"
- else:
- text = format_float_or_int_string(text)
- leaf.value = text
-
-
-def format_float_or_int_string(text: str) -> str:
- """Formats a float string like "1.0"."""
- if "." not in text:
- return text
-
- before, after = text.split(".")
- return f"{before or 0}.{after or 0}"
-
-
-def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None:
- """Make existing optional parentheses invisible or create new ones.
-
- `parens_after` is a set of string leaf values immediately after which parens
- should be put.
-
- Standardizes on visible parentheses for single-element tuples, and keeps
- existing visible parentheses for other tuples and generator expressions.
- """
- for pc in list_comments(node.prefix, is_endmarker=False):
- if pc.value in FMT_OFF:
- # This `node` has a prefix with `# fmt: off`, don't mess with parens.
- return
-
- check_lpar = False
- for index, child in enumerate(list(node.children)):
- # Add parentheses around long tuple unpacking in assignments.
- if (
- index == 0
- and isinstance(child, Node)
- and child.type == syms.testlist_star_expr
- ):
- check_lpar = True
-
- if check_lpar:
- if is_walrus_assignment(child):
- continue
- if child.type == syms.atom:
- # Determines if the underlying atom should be surrounded with
- # invisible params - also makes parens invisible recursively
- # within the atom and removes repeated invisible parens within
- # the atom
- should_surround_with_parens = maybe_make_parens_invisible_in_atom(
- child, parent=node
- )
-
- if should_surround_with_parens:
- lpar = Leaf(token.LPAR, "")
- rpar = Leaf(token.RPAR, "")
- index = child.remove() or 0
- node.insert_child(index, Node(syms.atom, [lpar, child, rpar]))
- elif is_one_tuple(child):
- # wrap child in visible parentheses
- lpar = Leaf(token.LPAR, "(")
- rpar = Leaf(token.RPAR, ")")
- child.remove()
- node.insert_child(index, Node(syms.atom, [lpar, child, rpar]))
- elif node.type == syms.import_from:
- # "import from" nodes store parentheses directly as part of
- # the statement
- if child.type == token.LPAR:
- # make parentheses invisible
- child.value = "" # type: ignore
- node.children[-1].value = "" # type: ignore
- elif child.type != token.STAR:
- # insert invisible parentheses
- node.insert_child(index, Leaf(token.LPAR, ""))
- node.append_child(Leaf(token.RPAR, ""))
- break
-
- elif not (isinstance(child, Leaf) and is_multiline_string(child)):
- # wrap child in invisible parentheses
- lpar = Leaf(token.LPAR, "")
- rpar = Leaf(token.RPAR, "")
- index = child.remove() or 0
- prefix = child.prefix
- child.prefix = ""
- new_child = Node(syms.atom, [lpar, child, rpar])
- new_child.prefix = prefix
- node.insert_child(index, new_child)
-
- check_lpar = isinstance(child, Leaf) and child.value in parens_after
-
-
-def normalize_fmt_off(node: Node) -> None:
- """Convert content between `# fmt: off`/`# fmt: on` into standalone comments."""
- try_again = True
- while try_again:
- try_again = convert_one_fmt_off_pair(node)
-
-
-def convert_one_fmt_off_pair(node: Node) -> bool:
- """Convert content of a single `# fmt: off`/`# fmt: on` into a standalone comment.
-
- Returns True if a pair was converted.
- """
- for leaf in node.leaves():
- previous_consumed = 0
- for comment in list_comments(leaf.prefix, is_endmarker=False):
- if comment.value in FMT_OFF:
- # We only want standalone comments. If there's no previous leaf or
- # the previous leaf is indentation, it's a standalone comment in
- # disguise.
- if comment.type != STANDALONE_COMMENT:
- prev = preceding_leaf(leaf)
- if prev and prev.type not in WHITESPACE:
- continue
-
- ignored_nodes = list(generate_ignored_nodes(leaf))
- if not ignored_nodes:
- continue
-
- first = ignored_nodes[0] # Can be a container node with the `leaf`.
- parent = first.parent
- prefix = first.prefix
- first.prefix = prefix[comment.consumed :]
- hidden_value = (
- comment.value + "\n" + "".join(str(n) for n in ignored_nodes)
- )
- if hidden_value.endswith("\n"):
- # That happens when one of the `ignored_nodes` ended with a NEWLINE
- # leaf (possibly followed by a DEDENT).
- hidden_value = hidden_value[:-1]
- first_idx = None
- for ignored in ignored_nodes:
- index = ignored.remove()
- if first_idx is None:
- first_idx = index
- assert parent is not None, "INTERNAL ERROR: fmt: on/off handling (1)"
- assert first_idx is not None, "INTERNAL ERROR: fmt: on/off handling (2)"
- parent.insert_child(
- first_idx,
- Leaf(
- STANDALONE_COMMENT,
- hidden_value,
- prefix=prefix[:previous_consumed] + "\n" * comment.newlines,
- ),
- )
- return True
-
- previous_consumed = comment.consumed
-
- return False
-
-
-def generate_ignored_nodes(leaf: Leaf) -> Iterator[LN]:
- """Starting from the container of `leaf`, generate all leaves until `# fmt: on`.
-
- Stops at the end of the block.
- """
- container: Optional[LN] = container_of(leaf)
- while container is not None and container.type != token.ENDMARKER:
- for comment in list_comments(container.prefix, is_endmarker=False):
- if comment.value in FMT_ON:
- return
-
- yield container
-
- container = container.next_sibling
-
-
-def maybe_make_parens_invisible_in_atom(node: LN, parent: LN) -> bool:
- """If it's safe, make the parens in the atom `node` invisible, recursively.
- Additionally, remove repeated, adjacent invisible parens from the atom `node`
- as they are redundant.
-
- Returns whether the node should itself be wrapped in invisible parentheses.
-
- """
- if (
- node.type != syms.atom
- or is_empty_tuple(node)
- or is_one_tuple(node)
- or (is_yield(node) and parent.type != syms.expr_stmt)
- or max_delimiter_priority_in_atom(node) >= COMMA_PRIORITY
- ):
- return False
-
- first = node.children[0]
- last = node.children[-1]
- if first.type == token.LPAR and last.type == token.RPAR:
- middle = node.children[1]
- # make parentheses invisible
- first.value = "" # type: ignore
- last.value = "" # type: ignore
- maybe_make_parens_invisible_in_atom(middle, parent=parent)
-
- if is_atom_with_invisible_parens(middle):
- # Strip the invisible parens from `middle` by replacing
- # it with the child in-between the invisible parens
- middle.replace(middle.children[1])
-
- return False
-
- return True
-
-
-def is_atom_with_invisible_parens(node: LN) -> bool:
- """Given a `LN`, determines whether it's an atom `node` with invisible
- parens. Useful in dedupe-ing and normalizing parens.
- """
- if isinstance(node, Leaf) or node.type != syms.atom:
- return False
-
- first, last = node.children[0], node.children[-1]
- return (
- isinstance(first, Leaf)
- and first.type == token.LPAR
- and first.value == ""
- and isinstance(last, Leaf)
- and last.type == token.RPAR
- and last.value == ""
- )
-
-
-def is_empty_tuple(node: LN) -> bool:
- """Return True if `node` holds an empty tuple."""
- return (
- node.type == syms.atom
- and len(node.children) == 2
- and node.children[0].type == token.LPAR
- and node.children[1].type == token.RPAR
- )
-
-
-def unwrap_singleton_parenthesis(node: LN) -> Optional[LN]:
- """Returns `wrapped` if `node` is of the shape ( wrapped ).
-
- Parenthesis can be optional. Returns None otherwise"""
- if len(node.children) != 3:
- return None
- lpar, wrapped, rpar = node.children
- if not (lpar.type == token.LPAR and rpar.type == token.RPAR):
- return None
-
- return wrapped
-
-
-def is_one_tuple(node: LN) -> bool:
- """Return True if `node` holds a tuple with one element, with or without parens."""
- if node.type == syms.atom:
- gexp = unwrap_singleton_parenthesis(node)
- if gexp is None or gexp.type != syms.testlist_gexp:
- return False
-
- return len(gexp.children) == 2 and gexp.children[1].type == token.COMMA
-
- return (
- node.type in IMPLICIT_TUPLE
- and len(node.children) == 2
- and node.children[1].type == token.COMMA
- )
-
-
-def is_walrus_assignment(node: LN) -> bool:
- """Return True iff `node` is of the shape ( test := test )"""
- inner = unwrap_singleton_parenthesis(node)
- return inner is not None and inner.type == syms.namedexpr_test
-
-
-def is_yield(node: LN) -> bool:
- """Return True if `node` holds a `yield` or `yield from` expression."""
- if node.type == syms.yield_expr:
- return True
-
- if node.type == token.NAME and node.value == "yield": # type: ignore
- return True
-
- if node.type != syms.atom:
- return False
-
- if len(node.children) != 3:
- return False
-
- lpar, expr, rpar = node.children
- if lpar.type == token.LPAR and rpar.type == token.RPAR:
- return is_yield(expr)
-
- return False
-
-
-def is_vararg(leaf: Leaf, within: Set[NodeType]) -> bool:
- """Return True if `leaf` is a star or double star in a vararg or kwarg.
-
- If `within` includes VARARGS_PARENTS, this applies to function signatures.
- If `within` includes UNPACKING_PARENTS, it applies to right hand-side
- extended iterable unpacking (PEP 3132) and additional unpacking
- generalizations (PEP 448).
- """
- if leaf.type not in VARARGS_SPECIALS or not leaf.parent:
- return False
-
- p = leaf.parent
- if p.type == syms.star_expr:
- # Star expressions are also used as assignment targets in extended
- # iterable unpacking (PEP 3132). See what its parent is instead.
- if not p.parent:
- return False
-
- p = p.parent
-
- return p.type in within
-
-
-def is_multiline_string(leaf: Leaf) -> bool:
- """Return True if `leaf` is a multiline string that actually spans many lines."""
- value = leaf.value.lstrip("furbFURB")
- return value[:3] in {'"""', "'''"} and "\n" in value
-
-
-def is_stub_suite(node: Node) -> bool:
- """Return True if `node` is a suite with a stub body."""
- if (
- len(node.children) != 4
- or node.children[0].type != token.NEWLINE
- or node.children[1].type != token.INDENT
- or node.children[3].type != token.DEDENT
- ):
- return False
-
- return is_stub_body(node.children[2])
-
-
-def is_stub_body(node: LN) -> bool:
- """Return True if `node` is a simple statement containing an ellipsis."""
- if not isinstance(node, Node) or node.type != syms.simple_stmt:
- return False
-
- if len(node.children) != 2:
- return False
-
- child = node.children[0]
- return (
- child.type == syms.atom
- and len(child.children) == 3
- and all(leaf == Leaf(token.DOT, ".") for leaf in child.children)
- )
-
-
-def max_delimiter_priority_in_atom(node: LN) -> Priority:
- """Return maximum delimiter priority inside `node`.
-
- This is specific to atoms with contents contained in a pair of parentheses.
- If `node` isn't an atom or there are no enclosing parentheses, returns 0.
- """
- if node.type != syms.atom:
- return 0
-
- first = node.children[0]
- last = node.children[-1]
- if not (first.type == token.LPAR and last.type == token.RPAR):
- return 0
-
- bt = BracketTracker()
- for c in node.children[1:-1]:
- if isinstance(c, Leaf):
- bt.mark(c)
- else:
- for leaf in c.leaves():
- bt.mark(leaf)
- try:
- return bt.max_delimiter_priority()
-
- except ValueError:
- return 0
-
-
-def ensure_visible(leaf: Leaf) -> None:
- """Make sure parentheses are visible.
-
- They could be invisible as part of some statements (see
- :func:`normalize_invisible_parens` and :func:`visit_import_from`).
- """
- if leaf.type == token.LPAR:
- leaf.value = "("
- elif leaf.type == token.RPAR:
- leaf.value = ")"
-
-
-def should_explode(line: Line, opening_bracket: Leaf) -> bool:
- """Should `line` immediately be split with `delimiter_split()` after RHS?"""
-
- if not (
- opening_bracket.parent
- and opening_bracket.parent.type in {syms.atom, syms.import_from}
- and opening_bracket.value in "[{("
- ):
- return False
-
- try:
- last_leaf = line.leaves[-1]
- exclude = {id(last_leaf)} if last_leaf.type == token.COMMA else set()
- max_priority = line.bracket_tracker.max_delimiter_priority(exclude=exclude)
- except (IndexError, ValueError):
- return False
-
- return max_priority == COMMA_PRIORITY
-
-
-def get_features_used(node: Node) -> Set[Feature]:
- """Return a set of (relatively) new Python features used in this file.
-
- Currently looking for:
- - f-strings;
- - underscores in numeric literals;
- - trailing commas after * or ** in function signatures and calls;
- - positional only arguments in function signatures and lambdas;
- """
- features: Set[Feature] = set()
- for n in node.pre_order():
- if n.type == token.STRING:
- value_head = n.value[:2] # type: ignore
- if value_head in {'f"', 'F"', "f'", "F'", "rf", "fr", "RF", "FR"}:
- features.add(Feature.F_STRINGS)
-
- elif n.type == token.NUMBER:
- if "_" in n.value: # type: ignore
- features.add(Feature.NUMERIC_UNDERSCORES)
-
- elif n.type == token.SLASH:
- if n.parent and n.parent.type in {syms.typedargslist, syms.arglist}:
- features.add(Feature.POS_ONLY_ARGUMENTS)
-
- elif n.type == token.COLONEQUAL:
- features.add(Feature.ASSIGNMENT_EXPRESSIONS)
-
- elif (
- n.type in {syms.typedargslist, syms.arglist}
- and n.children
- and n.children[-1].type == token.COMMA
- ):
- if n.type == syms.typedargslist:
- feature = Feature.TRAILING_COMMA_IN_DEF
- else:
- feature = Feature.TRAILING_COMMA_IN_CALL
-
- for ch in n.children:
- if ch.type in STARS:
- features.add(feature)
-
- if ch.type == syms.argument:
- for argch in ch.children:
- if argch.type in STARS:
- features.add(feature)
-
- return features
-
-
-def detect_target_versions(node: Node) -> Set[TargetVersion]:
- """Detect the version to target based on the nodes used."""
- features = get_features_used(node)
- return {
- version for version in TargetVersion if features <= VERSION_TO_FEATURES[version]
- }
-
-
-def generate_trailers_to_omit(line: Line, line_length: int) -> Iterator[Set[LeafID]]:
- """Generate sets of closing bracket IDs that should be omitted in a RHS.
-
- Brackets can be omitted if the entire trailer up to and including
- a preceding closing bracket fits in one line.
-
- Yielded sets are cumulative (contain results of previous yields, too). First
- set is empty.
- """
-
- omit: Set[LeafID] = set()
- yield omit
-
- length = 4 * line.depth
- opening_bracket = None
- closing_bracket = None
- inner_brackets: Set[LeafID] = set()
- for index, leaf, leaf_length in enumerate_with_length(line, reversed=True):
- length += leaf_length
- if length > line_length:
- break
-
- has_inline_comment = leaf_length > len(leaf.value) + len(leaf.prefix)
- if leaf.type == STANDALONE_COMMENT or has_inline_comment:
- break
-
- if opening_bracket:
- if leaf is opening_bracket:
- opening_bracket = None
- elif leaf.type in CLOSING_BRACKETS:
- inner_brackets.add(id(leaf))
- elif leaf.type in CLOSING_BRACKETS:
- if index > 0 and line.leaves[index - 1].type in OPENING_BRACKETS:
- # Empty brackets would fail a split so treat them as "inner"
- # brackets (e.g. only add them to the `omit` set if another
- # pair of brackets was good enough.
- inner_brackets.add(id(leaf))
- continue
-
- if closing_bracket:
- omit.add(id(closing_bracket))
- omit.update(inner_brackets)
- inner_brackets.clear()
- yield omit
-
- if leaf.value:
- opening_bracket = leaf.opening_bracket
- closing_bracket = leaf
-
-
-def get_future_imports(node: Node) -> Set[str]:
- """Return a set of __future__ imports in the file."""
- imports: Set[str] = set()
-
- def get_imports_from_children(children: List[LN]) -> Generator[str, None, None]:
- for child in children:
- if isinstance(child, Leaf):
- if child.type == token.NAME:
- yield child.value
- elif child.type == syms.import_as_name:
- orig_name = child.children[0]
- assert isinstance(orig_name, Leaf), "Invalid syntax parsing imports"
- assert orig_name.type == token.NAME, "Invalid syntax parsing imports"
- yield orig_name.value
- elif child.type == syms.import_as_names:
- yield from get_imports_from_children(child.children)
- else:
- raise AssertionError("Invalid syntax parsing imports")
-
- for child in node.children:
- if child.type != syms.simple_stmt:
- break
- first_child = child.children[0]
- if isinstance(first_child, Leaf):
- # Continue looking if we see a docstring; otherwise stop.
- if (
- len(child.children) == 2
- and first_child.type == token.STRING
- and child.children[1].type == token.NEWLINE
- ):
- continue
- else:
- break
- elif first_child.type == syms.import_from:
- module_name = first_child.children[1]
- if not isinstance(module_name, Leaf) or module_name.value != "__future__":
- break
- imports |= set(get_imports_from_children(first_child.children[3:]))
- else:
- break
- return imports
-
-
-def gen_python_files_in_dir(
- path: Path,
- root: Path,
- include: Pattern[str],
- exclude: Pattern[str],
- report: "Report",
-) -> Iterator[Path]:
- """Generate all files under `path` whose paths are not excluded by the
- `exclude` regex, but are included by the `include` regex.
-
- Symbolic links pointing outside of the `root` directory are ignored.
-
- `report` is where output about exclusions goes.
- """
- assert root.is_absolute(), f"INTERNAL ERROR: `root` must be absolute but is {root}"
- for child in path.iterdir():
- try:
- normalized_path = "/" + child.resolve().relative_to(root).as_posix()
- except ValueError:
- if child.is_symlink():
- report.path_ignored(
- child, f"is a symbolic link that points outside {root}"
- )
- continue
-
- raise
-
- if child.is_dir():
- normalized_path += "/"
- exclude_match = exclude.search(normalized_path)
- if exclude_match and exclude_match.group(0):
- report.path_ignored(child, f"matches the --exclude regular expression")
- continue
-
- if child.is_dir():
- yield from gen_python_files_in_dir(child, root, include, exclude, report)
-
- elif child.is_file():
- include_match = include.search(normalized_path)
- if include_match:
- yield child
-
-
-@lru_cache()
-def find_project_root(srcs: Iterable[str]) -> Path:
- """Return a directory containing .git, .hg, or pyproject.toml.
-
- That directory can be one of the directories passed in `srcs` or their
- common parent.
-
- If no directory in the tree contains a marker that would specify it's the
- project root, the root of the file system is returned.
- """
- if not srcs:
- return Path("/").resolve()
-
- common_base = min(Path(src).resolve() for src in srcs)
- if common_base.is_dir():
- # Append a fake file so `parents` below returns `common_base_dir`, too.
- common_base /= "fake-file"
- for directory in common_base.parents:
- if (directory / ".git").is_dir():
- return directory
-
- if (directory / ".hg").is_dir():
- return directory
-
- if (directory / "pyproject.toml").is_file():
- return directory
-
- return directory
-
-
-@dataclass
-class Report:
- """Provides a reformatting counter. Can be rendered with `str(report)`."""
-
- check: bool = False
- quiet: bool = False
- verbose: bool = False
- change_count: int = 0
- same_count: int = 0
- failure_count: int = 0
-
- def done(self, src: Path, changed: Changed) -> None:
- """Increment the counter for successful reformatting. Write out a message."""
- if changed is Changed.YES:
- reformatted = "would reformat" if self.check else "reformatted"
- if self.verbose or not self.quiet:
- out(f"{reformatted} {src}")
- self.change_count += 1
- else:
- if self.verbose:
- if changed is Changed.NO:
- msg = f"{src} already well formatted, good job."
- else:
- msg = f"{src} wasn't modified on disk since last run."
- out(msg, bold=False)
- self.same_count += 1
-
- def failed(self, src: Path, message: str) -> None:
- """Increment the counter for failed reformatting. Write out a message."""
- err(f"error: cannot format {src}: {message}")
- self.failure_count += 1
-
- def path_ignored(self, path: Path, message: str) -> None:
- if self.verbose:
- out(f"{path} ignored: {message}", bold=False)
-
- @property
- def return_code(self) -> int:
- """Return the exit code that the app should use.
-
- This considers the current state of changed files and failures:
- - if there were any failures, return 123;
- - if any files were changed and --check is being used, return 1;
- - otherwise return 0.
- """
- # According to http://tldp.org/LDP/abs/html/exitcodes.html starting with
- # 126 we have special return codes reserved by the shell.
- if self.failure_count:
- return 123
-
- elif self.change_count and self.check:
- return 1
-
- return 0
-
- def __str__(self) -> str:
- """Render a color report of the current state.
-
- Use `click.unstyle` to remove colors.
- """
- if self.check:
- reformatted = "would be reformatted"
- unchanged = "would be left unchanged"
- failed = "would fail to reformat"
- else:
- reformatted = "reformatted"
- unchanged = "left unchanged"
- failed = "failed to reformat"
- report = []
- if self.change_count:
- s = "s" if self.change_count > 1 else ""
- report.append(
- click.style(f"{self.change_count} file{s} {reformatted}", bold=True)
- )
- if self.same_count:
- s = "s" if self.same_count > 1 else ""
- report.append(f"{self.same_count} file{s} {unchanged}")
- if self.failure_count:
- s = "s" if self.failure_count > 1 else ""
- report.append(
- click.style(f"{self.failure_count} file{s} {failed}", fg="red")
- )
- return ", ".join(report) + "."
-
-
-def parse_ast(src: str) -> Union[ast.AST, ast3.AST, ast27.AST]:
- filename = "<unknown>"
- if sys.version_info >= (3, 8):
- # TODO: support Python 4+ ;)
- for minor_version in range(sys.version_info[1], 4, -1):
- try:
- return ast.parse(src, filename, feature_version=(3, minor_version))
- except SyntaxError:
- continue
- else:
- for feature_version in (7, 6):
- try:
- return ast3.parse(src, filename, feature_version=feature_version)
- except SyntaxError:
- continue
-
- return ast27.parse(src)
-
-
-def _fixup_ast_constants(
- node: Union[ast.AST, ast3.AST, ast27.AST]
-) -> Union[ast.AST, ast3.AST, ast27.AST]:
- """Map ast nodes deprecated in 3.8 to Constant."""
- # casts are required until this is released:
- # https://github.com/python/typeshed/pull/3142
- if isinstance(node, (ast.Str, ast3.Str, ast27.Str, ast.Bytes, ast3.Bytes)):
- return cast(ast.AST, ast.Constant(value=node.s))
- elif isinstance(node, (ast.Num, ast3.Num, ast27.Num)):
- return cast(ast.AST, ast.Constant(value=node.n))
- elif isinstance(node, (ast.NameConstant, ast3.NameConstant)):
- return cast(ast.AST, ast.Constant(value=node.value))
- return node
-
-
-def assert_equivalent(src: str, dst: str) -> None:
- """Raise AssertionError if `src` and `dst` aren't equivalent."""
-
- def _v(node: Union[ast.AST, ast3.AST, ast27.AST], depth: int = 0) -> Iterator[str]:
- """Simple visitor generating strings to compare ASTs by content."""
-
- node = _fixup_ast_constants(node)
-
- yield f"{' ' * depth}{node.__class__.__name__}("
-
- for field in sorted(node._fields):
- # TypeIgnore has only one field 'lineno' which breaks this comparison
- type_ignore_classes = (ast3.TypeIgnore, ast27.TypeIgnore)
- if sys.version_info >= (3, 8):
- type_ignore_classes += (ast.TypeIgnore,)
- if isinstance(node, type_ignore_classes):
- break
-
- try:
- value = getattr(node, field)
- except AttributeError:
- continue
-
- yield f"{' ' * (depth+1)}{field}="
-
- if isinstance(value, list):
- for item in value:
- # Ignore nested tuples within del statements, because we may insert
- # parentheses and they change the AST.
- if (
- field == "targets"
- and isinstance(node, (ast.Delete, ast3.Delete, ast27.Delete))
- and isinstance(item, (ast.Tuple, ast3.Tuple, ast27.Tuple))
- ):
- for item in item.elts:
- yield from _v(item, depth + 2)
- elif isinstance(item, (ast.AST, ast3.AST, ast27.AST)):
- yield from _v(item, depth + 2)
-
- elif isinstance(value, (ast.AST, ast3.AST, ast27.AST)):
- yield from _v(value, depth + 2)
-
- else:
- yield f"{' ' * (depth+2)}{value!r}, # {value.__class__.__name__}"
-
- yield f"{' ' * depth}) # /{node.__class__.__name__}"
-
- try:
- src_ast = parse_ast(src)
- except Exception as exc:
- raise AssertionError(
- f"cannot use --safe with this file; failed to parse source file. "
- f"AST error message: {exc}"
- )
-
- try:
- dst_ast = parse_ast(dst)
- except Exception as exc:
- log = dump_to_file("".join(traceback.format_tb(exc.__traceback__)), dst)
- raise AssertionError(
- f"INTERNAL ERROR: Black produced invalid code: {exc}. "
- f"Please report a bug on https://github.com/psf/black/issues. "
- f"This invalid output might be helpful: {log}"
- ) from None
-
- src_ast_str = "\n".join(_v(src_ast))
- dst_ast_str = "\n".join(_v(dst_ast))
- if src_ast_str != dst_ast_str:
- log = dump_to_file(diff(src_ast_str, dst_ast_str, "src", "dst"))
- raise AssertionError(
- f"INTERNAL ERROR: Black produced code that is not equivalent to "
- f"the source. "
- f"Please report a bug on https://github.com/psf/black/issues. "
- f"This diff might be helpful: {log}"
- ) from None
-
-
-def assert_stable(src: str, dst: str, mode: FileMode) -> None:
- """Raise AssertionError if `dst` reformats differently the second time."""
- newdst = format_str(dst, mode=mode)
- if dst != newdst:
- log = dump_to_file(
- diff(src, dst, "source", "first pass"),
- diff(dst, newdst, "first pass", "second pass"),
- )
- raise AssertionError(
- f"INTERNAL ERROR: Black produced different code on the second pass "
- f"of the formatter. "
- f"Please report a bug on https://github.com/psf/black/issues. "
- f"This diff might be helpful: {log}"
- ) from None
-
-
-def dump_to_file(*output: str) -> str:
- """Dump `output` to a temporary file. Return path to the file."""
- with tempfile.NamedTemporaryFile(
- mode="w", prefix="blk_", suffix=".log", delete=False, encoding="utf8"
- ) as f:
- for lines in output:
- f.write(lines)
- if lines and lines[-1] != "\n":
- f.write("\n")
- return f.name
-
-
-@contextmanager
-def nullcontext() -> Iterator[None]:
- """Return context manager that does nothing.
- Similar to `nullcontext` from python 3.7"""
- yield
-
-
-def diff(a: str, b: str, a_name: str, b_name: str) -> str:
- """Return a unified diff string between strings `a` and `b`."""
- import difflib
-
- a_lines = [line + "\n" for line in a.split("\n")]
- b_lines = [line + "\n" for line in b.split("\n")]
- return "".join(
- difflib.unified_diff(a_lines, b_lines, fromfile=a_name, tofile=b_name, n=5)
- )
-
-
-def cancel(tasks: Iterable[asyncio.Task]) -> None:
- """asyncio signal handler that cancels all `tasks` and reports to stderr."""
- err("Aborted!")
- for task in tasks:
- task.cancel()
-
-
-def shutdown(loop: asyncio.AbstractEventLoop) -> None:
- """Cancel all pending tasks on `loop`, wait for them, and close the loop."""
- try:
- if sys.version_info[:2] >= (3, 7):
- all_tasks = asyncio.all_tasks
- else:
- all_tasks = asyncio.Task.all_tasks
- # This part is borrowed from asyncio/runners.py in Python 3.7b2.
- to_cancel = [task for task in all_tasks(loop) if not task.done()]
- if not to_cancel:
- return
-
- for task in to_cancel:
- task.cancel()
- loop.run_until_complete(
- asyncio.gather(*to_cancel, loop=loop, return_exceptions=True)
- )
- finally:
- # `concurrent.futures.Future` objects cannot be cancelled once they
- # are already running. There might be some when the `shutdown()` happened.
- # Silence their logger's spew about the event loop being closed.
- cf_logger = logging.getLogger("concurrent.futures")
- cf_logger.setLevel(logging.CRITICAL)
- loop.close()
-
-
-def sub_twice(regex: Pattern[str], replacement: str, original: str) -> str:
- """Replace `regex` with `replacement` twice on `original`.
-
- This is used by string normalization to perform replaces on
- overlapping matches.
- """
- return regex.sub(replacement, regex.sub(replacement, original))
-
-
-def re_compile_maybe_verbose(regex: str) -> Pattern[str]:
- """Compile a regular expression string in `regex`.
-
- If it contains newlines, use verbose mode.
- """
- if "\n" in regex:
- regex = "(?x)" + regex
- return re.compile(regex)
-
-
-def enumerate_reversed(sequence: Sequence[T]) -> Iterator[Tuple[Index, T]]:
- """Like `reversed(enumerate(sequence))` if that were possible."""
- index = len(sequence) - 1
- for element in reversed(sequence):
- yield (index, element)
- index -= 1
-
-
-def enumerate_with_length(
- line: Line, reversed: bool = False
-) -> Iterator[Tuple[Index, Leaf, int]]:
- """Return an enumeration of leaves with their length.
-
- Stops prematurely on multiline strings and standalone comments.
- """
- op = cast(
- Callable[[Sequence[Leaf]], Iterator[Tuple[Index, Leaf]]],
- enumerate_reversed if reversed else enumerate,
- )
- for index, leaf in op(line.leaves):
- length = len(leaf.prefix) + len(leaf.value)
- if "\n" in leaf.value:
- return # Multiline strings, we can't continue.
-
- for comment in line.comments_after(leaf):
- length += len(comment.value)
-
- yield index, leaf, length
-
-
-def is_line_short_enough(line: Line, *, line_length: int, line_str: str = "") -> bool:
- """Return True if `line` is no longer than `line_length`.
-
- Uses the provided `line_str` rendering, if any, otherwise computes a new one.
- """
- if not line_str:
- line_str = str(line).strip("\n")
- return (
- len(line_str) <= line_length
- and "\n" not in line_str # multiline strings
- and not line.contains_standalone_comments()
- )
-
-
-def can_be_split(line: Line) -> bool:
- """Return False if the line cannot be split *for sure*.
-
- This is not an exhaustive search but a cheap heuristic that we can use to
- avoid some unfortunate formattings (mostly around wrapping unsplittable code
- in unnecessary parentheses).
- """
- leaves = line.leaves
- if len(leaves) < 2:
- return False
-
- if leaves[0].type == token.STRING and leaves[1].type == token.DOT:
- call_count = 0
- dot_count = 0
- next = leaves[-1]
- for leaf in leaves[-2::-1]:
- if leaf.type in OPENING_BRACKETS:
- if next.type not in CLOSING_BRACKETS:
- return False
-
- call_count += 1
- elif leaf.type == token.DOT:
- dot_count += 1
- elif leaf.type == token.NAME:
- if not (next.type == token.DOT or next.type in OPENING_BRACKETS):
- return False
-
- elif leaf.type not in CLOSING_BRACKETS:
- return False
-
- if dot_count > 1 and call_count > 1:
- return False
-
- return True
-
-
-def can_omit_invisible_parens(line: Line, line_length: int) -> bool:
- """Does `line` have a shape safe to reformat without optional parens around it?
-
- Returns True for only a subset of potentially nice looking formattings but
- the point is to not return false positives that end up producing lines that
- are too long.
- """
- bt = line.bracket_tracker
- if not bt.delimiters:
- # Without delimiters the optional parentheses are useless.
- return True
-
- max_priority = bt.max_delimiter_priority()
- if bt.delimiter_count_with_priority(max_priority) > 1:
- # With more than one delimiter of a kind the optional parentheses read better.
- return False
-
- if max_priority == DOT_PRIORITY:
- # A single stranded method call doesn't require optional parentheses.
- return True
-
- assert len(line.leaves) >= 2, "Stranded delimiter"
-
- first = line.leaves[0]
- second = line.leaves[1]
- penultimate = line.leaves[-2]
- last = line.leaves[-1]
-
- # With a single delimiter, omit if the expression starts or ends with
- # a bracket.
- if first.type in OPENING_BRACKETS and second.type not in CLOSING_BRACKETS:
- remainder = False
- length = 4 * line.depth
- for _index, leaf, leaf_length in enumerate_with_length(line):
- if leaf.type in CLOSING_BRACKETS and leaf.opening_bracket is first:
- remainder = True
- if remainder:
- length += leaf_length
- if length > line_length:
- break
-
- if leaf.type in OPENING_BRACKETS:
- # There are brackets we can further split on.
- remainder = False
-
- else:
- # checked the entire string and line length wasn't exceeded
- if len(line.leaves) == _index + 1:
- return True
-
- # Note: we are not returning False here because a line might have *both*
- # a leading opening bracket and a trailing closing bracket. If the
- # opening bracket doesn't match our rule, maybe the closing will.
-
- if (
- last.type == token.RPAR
- or last.type == token.RBRACE
- or (
- # don't use indexing for omitting optional parentheses;
- # it looks weird
- last.type == token.RSQB
- and last.parent
- and last.parent.type != syms.trailer
- )
- ):
- if penultimate.type in OPENING_BRACKETS:
- # Empty brackets don't help.
- return False
-
- if is_multiline_string(first):
- # Additional wrapping of a multiline string in this situation is
- # unnecessary.
- return True
-
- length = 4 * line.depth
- seen_other_brackets = False
- for _index, leaf, leaf_length in enumerate_with_length(line):
- length += leaf_length
- if leaf is last.opening_bracket:
- if seen_other_brackets or length <= line_length:
- return True
-
- elif leaf.type in OPENING_BRACKETS:
- # There are brackets we can further split on.
- seen_other_brackets = True
-
- return False
-
-
-def get_cache_file(mode: FileMode) -> Path:
- return CACHE_DIR / f"cache.{mode.get_cache_key()}.pickle"
-
-
-def read_cache(mode: FileMode) -> Cache:
- """Read the cache if it exists and is well formed.
-
- If it is not well formed, the call to write_cache later should resolve the issue.
- """
- cache_file = get_cache_file(mode)
- if not cache_file.exists():
- return {}
-
- with cache_file.open("rb") as fobj:
- try:
- cache: Cache = pickle.load(fobj)
- except pickle.UnpicklingError:
- return {}
-
- return cache
-
-
-def get_cache_info(path: Path) -> CacheInfo:
- """Return the information used to check if a file is already formatted or not."""
- stat = path.stat()
- return stat.st_mtime, stat.st_size
-
-
-def filter_cached(cache: Cache, sources: Iterable[Path]) -> Tuple[Set[Path], Set[Path]]:
- """Split an iterable of paths in `sources` into two sets.
-
- The first contains paths of files that modified on disk or are not in the
- cache. The other contains paths to non-modified files.
- """
- todo, done = set(), set()
- for src in sources:
- src = src.resolve()
- if cache.get(src) != get_cache_info(src):
- todo.add(src)
- else:
- done.add(src)
- return todo, done
-
-
-def write_cache(cache: Cache, sources: Iterable[Path], mode: FileMode) -> None:
- """Update the cache file."""
- cache_file = get_cache_file(mode)
- try:
- CACHE_DIR.mkdir(parents=True, exist_ok=True)
- new_cache = {**cache, **{src.resolve(): get_cache_info(src) for src in sources}}
- with tempfile.NamedTemporaryFile(dir=str(cache_file.parent), delete=False) as f:
- pickle.dump(new_cache, f, protocol=pickle.HIGHEST_PROTOCOL)
- os.replace(f.name, cache_file)
- except OSError:
- pass
-
-
-def patch_click() -> None:
- """Make Click not crash.
-
- On certain misconfigured environments, Python 3 selects the ASCII encoding as the
- default which restricts paths that it can access during the lifetime of the
- application. Click refuses to work in this scenario by raising a RuntimeError.
-
- In case of Black the likelihood that non-ASCII characters are going to be used in
- file paths is minimal since it's Python source code. Moreover, this crash was
- spurious on Python 3.7 thanks to PEP 538 and PEP 540.
- """
- try:
- from click import core
- from click import _unicodefun # type: ignore
- except ModuleNotFoundError:
- return
-
- for module in (core, _unicodefun):
- if hasattr(module, "_verify_python3_env"):
- module._verify_python3_env = lambda: None
-
-
-def patched_main() -> None:
- freeze_support()
- patch_click()
- main()
-
-
-if __name__ == "__main__":
- patched_main()