Generating lines of code.
"""
import sys
-from dataclasses import dataclass
+from dataclasses import replace
from enum import Enum, auto
from functools import partial, wraps
from typing import Collection, Iterator, List, Optional, Set, Union, cast
from black.comments import FMT_OFF, generate_comments, list_comments
from black.lines import (
Line,
+ RHSResult,
append_leaves,
can_be_split,
can_omit_invisible_parens,
Visitor,
ensure_visible,
is_arith_like,
+ is_async_stmt_or_funcdef,
is_atom_with_invisible_parens,
is_docstring,
is_empty_tuple,
is_stub_body,
is_stub_suite,
is_tuple_containing_walrus,
+ is_type_ignore_comment_string,
is_vararg,
is_walrus_assignment,
is_yield,
self.current_line.depth += indent
return # Line is empty, don't emit. Creating a new one unnecessary.
+ if (
+ Preview.improved_async_statements_handling in self.mode
+ and len(self.current_line.leaves) == 1
+ and is_async_stmt_or_funcdef(self.current_line.leaves[0])
+ ):
+ # Special case for async def/for/with statements. `visit_async_stmt`
+ # adds an `ASYNC` leaf then visits the child def/for/with statement
+ # nodes. Line yields from those nodes shouldn't treat the former
+ # `ASYNC` leaf as a complete line.
+ return
+
complete_line = self.current_line
self.current_line = Line(mode=self.mode, depth=complete_line.depth + indent)
yield complete_line
yield from self.visit(child)
+ def visit_typeparams(self, node: Node) -> Iterator[Line]:
+ yield from self.visit_default(node)
+ node.children[0].prefix = ""
+
+ def visit_typevartuple(self, node: Node) -> Iterator[Line]:
+ yield from self.visit_default(node)
+ node.children[1].prefix = ""
+
+ def visit_paramspec(self, node: Node) -> Iterator[Line]:
+ yield from self.visit_default(node)
+ node.children[1].prefix = ""
+
def visit_dictsetmaker(self, node: Node) -> Iterator[Line]:
if Preview.wrap_long_dict_values_in_parens in self.mode:
for i, child in enumerate(node.children):
break
internal_stmt = next(children)
- for child in internal_stmt.children:
- yield from self.visit(child)
+ if Preview.improved_async_statements_handling in self.mode:
+ yield from self.visit(internal_stmt)
+ else:
+ for child in internal_stmt.children:
+ yield from self.visit(child)
def visit_decorators(self, node: Node) -> Iterator[Line]:
"""Visit decorators."""
and not line.should_split_rhs
and not line.magic_trailing_comma
and (
- is_line_short_enough(line, line_length=mode.line_length, line_str=line_str)
+ is_line_short_enough(line, mode=mode, line_str=line_str)
or line.contains_unsplittable_type_ignore()
)
and not (line.inside_brackets and line.contains_standalone_comments())
bracket pair instead.
"""
for omit in generate_trailers_to_omit(line, mode.line_length):
- lines = list(
- right_hand_split(line, mode.line_length, features, omit=omit)
- )
+ lines = list(right_hand_split(line, mode, features, omit=omit))
# Note: this check is only able to figure out if the first line of the
# *current* transformation fits in the line length. This is true only
# for simple cases. All others require running more transforms via
# `transform_line()`. This check doesn't know if those would succeed.
- if is_line_short_enough(lines[0], line_length=mode.line_length):
+ if is_line_short_enough(lines[0], mode=mode):
yield from lines
return
# This mostly happens to multiline strings that are by definition
# reported as not fitting a single line, as well as lines that contain
# trailing commas (those have to be exploded).
- yield from right_hand_split(
- line, line_length=mode.line_length, features=features
- )
+ yield from right_hand_split(line, mode, features=features)
# HACK: nested functions (like _rhs) compiled by mypyc don't retain their
# __name__ attribute which is needed in `run_transformer` further down.
yield result
-@dataclass
-class _RHSResult:
- """Intermediate split result from a right hand split."""
-
- head: Line
- body: Line
- tail: Line
- opening_bracket: Leaf
- closing_bracket: Leaf
-
-
def right_hand_split(
line: Line,
- line_length: int,
+ mode: Mode,
features: Collection[Feature] = (),
omit: Collection[LeafID] = (),
) -> Iterator[Line]:
"""
rhs_result = _first_right_hand_split(line, omit=omit)
yield from _maybe_split_omitting_optional_parens(
- rhs_result, line, line_length, features=features, omit=omit
+ rhs_result, line, mode, features=features, omit=omit
)
def _first_right_hand_split(
line: Line,
omit: Collection[LeafID] = (),
-) -> _RHSResult:
+) -> RHSResult:
"""Split the line into head, body, tail starting with the last bracket pair.
Note: this function should not have side effects. It's relied upon by
tail_leaves, line, opening_bracket, component=_BracketSplitComponent.tail
)
bracket_split_succeeded_or_raise(head, body, tail)
- return _RHSResult(head, body, tail, opening_bracket, closing_bracket)
+ return RHSResult(head, body, tail, opening_bracket, closing_bracket)
def _maybe_split_omitting_optional_parens(
- rhs: _RHSResult,
+ rhs: RHSResult,
line: Line,
- line_length: int,
+ mode: Mode,
features: Collection[Feature] = (),
omit: Collection[LeafID] = (),
) -> Iterator[Line]:
# there are no standalone comments in the body
and not rhs.body.contains_standalone_comments(0)
# and we can actually remove the parens
- and can_omit_invisible_parens(rhs.body, line_length)
+ and can_omit_invisible_parens(rhs, mode.line_length)
):
omit = {id(rhs.closing_bracket), *omit}
try:
- # The _RHSResult Omitting Optional Parens.
+ # The RHSResult Omitting Optional Parens.
rhs_oop = _first_right_hand_split(line, omit=omit)
if not (
Preview.prefer_splitting_right_hand_side_of_assignments in line.mode
# the split is right after `=`
and len(rhs.head.leaves) >= 2
and rhs.head.leaves[-2].type == token.EQUAL
- # the left side of assignement contains brackets
+ # the left side of assignment contains brackets
and any(leaf.type in BRACKETS for leaf in rhs.head.leaves[:-1])
# the left side of assignment is short enough (the -1 is for the ending
# optional paren)
- and is_line_short_enough(rhs.head, line_length=line_length - 1)
+ and is_line_short_enough(
+ rhs.head, mode=replace(mode, line_length=mode.line_length - 1)
+ )
# the left side of assignment won't explode further because of magic
# trailing comma
and rhs.head.magic_trailing_comma is None
# the split by omitting optional parens isn't preferred by some other
# reason
- and not _prefer_split_rhs_oop(rhs_oop, line_length=line_length)
+ and not _prefer_split_rhs_oop(rhs_oop, mode)
):
yield from _maybe_split_omitting_optional_parens(
- rhs_oop, line, line_length, features=features, omit=omit
+ rhs_oop, line, mode, features=features, omit=omit
)
return
except CannotSplit as e:
if not (
- can_be_split(rhs.body)
- or is_line_short_enough(rhs.body, line_length=line_length)
+ can_be_split(rhs.body) or is_line_short_enough(rhs.body, mode=mode)
):
raise CannotSplit(
"Splitting failed, body is still too long and can't be split."
yield result
-def _prefer_split_rhs_oop(rhs_oop: _RHSResult, line_length: int) -> bool:
+def _prefer_split_rhs_oop(rhs_oop: RHSResult, mode: Mode) -> bool:
"""
Returns whether we should prefer the result from a split omitting optional parens.
"""
# the first line still contains the `=`)
any(leaf.type == token.EQUAL for leaf in rhs_oop.head.leaves)
# the first line is short enough
- and is_line_short_enough(rhs_oop.head, line_length=line_length)
+ and is_line_short_enough(rhs_oop.head, mode=mode)
)
# contains unsplittable type ignore
or rhs_oop.head.contains_unsplittable_type_ignore()
)
if isinstance(node, Node) and isinstance(node.prev_sibling, Leaf)
)
+ # Except the false negatives above for PEP 604 unions where we
+ # can't add the comma.
+ and not (
+ leaves[0].parent
+ and leaves[0].parent.next_sibling
+ and leaves[0].parent.next_sibling.type == token.VBAR
+ )
)
if original.is_import or no_commas:
if is_lpar_token(first) and is_rpar_token(last):
middle = node.children[1]
# make parentheses invisible
- first.value = ""
- last.value = ""
+ if (
+ # If the prefix of `middle` includes a type comment with
+ # ignore annotation, then we do not remove the parentheses
+ not is_type_ignore_comment_string(middle.prefix.strip())
+ ):
+ first.value = ""
+ last.value = ""
maybe_make_parens_invisible_in_atom(
middle,
parent=parent,
or line.contains_multiline_strings()
or result[0].contains_uncollapsable_type_comments()
or result[0].contains_unsplittable_type_ignore()
- or is_line_short_enough(result[0], line_length=mode.line_length)
+ or is_line_short_enough(result[0], mode=mode)
# If any leaves have no parents (which _can_ occur since
# `transform(line)` potentially destroys the line's underlying node
# structure), then we can't proceed. Doing so would cause the below
second_opinion = run_transformer(
line_copy, transform, mode, features_fop, line_str=line_str
)
- if all(
- is_line_short_enough(ln, line_length=mode.line_length) for ln in second_opinion
- ):
+ if all(is_line_short_enough(ln, mode=mode) for ln in second_opinion):
result = second_opinion
return result