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
"""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, preview=self.mode.preview):
+ for comment in generate_comments(node):
if any_open_brackets:
# any comment within brackets is subject to splitting
self.current_line.append(comment)
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):
def visit_funcdef(self, node: Node) -> Iterator[Line]:
"""Visit function definition."""
- if Preview.annotation_parens not in self.mode:
- yield from self.visit_stmt(node, keywords={"def"}, parens=set())
- else:
- yield from self.line()
+ yield from self.line()
- # Remove redundant brackets around return type annotation.
- is_return_annotation = False
- for child in node.children:
- if child.type == token.RARROW:
- is_return_annotation = True
- elif is_return_annotation:
- if child.type == syms.atom and child.children[0].type == token.LPAR:
- if maybe_make_parens_invisible_in_atom(
- child,
- parent=node,
- remove_brackets_around_comma=False,
- ):
- wrap_in_parentheses(node, child, visible=False)
- else:
+ # Remove redundant brackets around return type annotation.
+ is_return_annotation = False
+ for child in node.children:
+ if child.type == token.RARROW:
+ is_return_annotation = True
+ elif is_return_annotation:
+ if child.type == syms.atom and child.children[0].type == token.LPAR:
+ if maybe_make_parens_invisible_in_atom(
+ child,
+ parent=node,
+ remove_brackets_around_comma=False,
+ ):
wrap_in_parentheses(node, child, visible=False)
- is_return_annotation = False
+ else:
+ wrap_in_parentheses(node, child, visible=False)
+ is_return_annotation = False
- for child in node.children:
- yield from self.visit(child)
+ for child in node.children:
+ yield from self.visit(child)
def visit_match_case(self, node: Node) -> Iterator[Line]:
"""Visit either a match or case statement."""
def visit_suite(self, node: Node) -> Iterator[Line]:
"""Visit a suite."""
- if self.mode.is_pyi and is_stub_suite(node):
+ if (
+ self.mode.is_pyi or Preview.dummy_implementations in self.mode
+ ) and is_stub_suite(node):
yield from self.visit(node.children[2])
else:
yield from self.visit_default(node)
is_suite_like = node.parent and node.parent.type in STATEMENT
if is_suite_like:
- if self.mode.is_pyi and is_stub_body(node):
+ if (
+ self.mode.is_pyi or Preview.dummy_implementations in self.mode
+ ) and is_stub_body(node):
yield from self.visit_default(node)
else:
yield from self.line(+1)
else:
if (
- not self.mode.is_pyi
+ not (self.mode.is_pyi or Preview.dummy_implementations in self.mode)
or not node.parent
or not is_stub_suite(node.parent)
):
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."""
):
wrap_in_parentheses(node, leaf)
- if Preview.remove_redundant_parens in self.mode:
- remove_await_parens(node)
+ remove_await_parens(node)
yield from self.visit_default(node)
node.insert_child(index, Node(syms.atom, [lpar, operand, rpar]))
yield from self.visit_default(node)
+ def visit_tname(self, node: Node) -> Iterator[Line]:
+ """
+ Add potential parentheses around types in function parameter lists to be made
+ into real parentheses in case the type hint is too long to fit on a line
+ Examples:
+ def foo(a: int, b: float = 7): ...
+
+ ->
+
+ def foo(a: (int), b: (float) = 7): ...
+ """
+ if Preview.parenthesize_long_type_hints in self.mode:
+ assert len(node.children) == 3
+ if maybe_make_parens_invisible_in_atom(node.children[2], parent=node):
+ wrap_in_parentheses(node, node.children[2], visible=False)
+
+ yield from self.visit_default(node)
+
def visit_STRING(self, leaf: Leaf) -> Iterator[Line]:
if Preview.hex_codes_in_unicode_sequences in self.mode:
normalize_unicode_escape_sequences(leaf)
if is_docstring(leaf) and "\\\n" not in leaf.value:
# We're ignoring docstrings with backslash newline escapes because changing
# indentation of those changes the AST representation of the code.
- if Preview.normalize_docstring_quotes_and_prefixes_properly in self.mode:
- # There was a bug where --skip-string-normalization wouldn't stop us
- # from normalizing docstring prefixes. To maintain stability, we can
- # only address this buggy behaviour while the preview style is enabled.
- if self.mode.string_normalization:
- docstring = normalize_string_prefix(leaf.value)
- # visit_default() does handle string normalization for us, but
- # since this method acts differently depending on quote style (ex.
- # see padding logic below), there's a possibility for unstable
- # formatting as visit_default() is called *after*. To avoid a
- # situation where this function formats a docstring differently on
- # the second pass, normalize it early.
- docstring = normalize_string_quotes(docstring)
- else:
- docstring = leaf.value
- else:
- # ... otherwise, we'll keep the buggy behaviour >.<
+ if self.mode.string_normalization:
docstring = normalize_string_prefix(leaf.value)
+ # visit_default() does handle string normalization for us, but
+ # since this method acts differently depending on quote style (ex.
+ # see padding logic below), there's a possibility for unstable
+ # formatting as visit_default() is called *after*. To avoid a
+ # situation where this function formats a docstring differently on
+ # the second pass, normalize it early.
+ docstring = normalize_string_quotes(docstring)
+ else:
+ docstring = leaf.value
prefix = get_string_prefix(docstring)
docstring = docstring[len(prefix) :] # Remove the prefix
quote_char = docstring[0]
quote = quote_char * quote_len
# It's invalid to put closing single-character quotes on a new line.
- if Preview.long_docstring_quotes_on_newline in self.mode and quote_len == 3:
+ if self.mode and quote_len == 3:
# We need to find the length of the last line of the docstring
# to find if we can add the closing quotes to the line without
# exceeding the maximum line length.
self.visit_try_stmt = partial(
v, keywords={"try", "except", "else", "finally"}, parens=Ø
)
- if self.mode.preview:
- self.visit_except_clause = partial(
- v, keywords={"except"}, parens={"except"}
- )
- self.visit_with_stmt = partial(v, keywords={"with"}, parens={"with"})
- else:
- self.visit_except_clause = partial(v, keywords={"except"}, parens=Ø)
- self.visit_with_stmt = partial(v, keywords={"with"}, parens=Ø)
+ self.visit_except_clause = partial(v, keywords={"except"}, parens={"except"})
+ self.visit_with_stmt = partial(v, keywords={"with"}, parens={"with"})
self.visit_classdef = partial(v, keywords={"class"}, parens=Ø)
- self.visit_expr_stmt = partial(v, keywords=Ø, parens=ASSIGNMENTS)
+
+ # When this is moved out of preview, add ":" directly to ASSIGNMENTS in nodes.py
+ if Preview.parenthesize_long_type_hints in self.mode:
+ assignments = ASSIGNMENTS | {":"}
+ else:
+ assignments = ASSIGNMENTS
+ 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"})
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())
transformers = [string_merge, string_paren_strip]
else:
transformers = []
- elif line.is_def:
+ elif line.is_def and not should_split_funcdef_with_rhs(line, mode):
transformers = [left_hand_split]
else:
def _rhs(
- self: object, line: Line, features: Collection[Feature]
+ self: object, line: Line, features: Collection[Feature], mode: Mode
) -> Iterator[Line]:
"""Wraps calls to `right_hand_split`.
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 line
+def should_split_funcdef_with_rhs(line: Line, mode: Mode) -> bool:
+ """If a funcdef has a magic trailing comma in the return type, then we should first
+ split the line with rhs to respect the comma.
+ """
+ if Preview.respect_magic_trailing_comma_in_return_type not in mode:
+ return False
+
+ return_type_leaves: List[Leaf] = []
+ in_return_type = False
+
+ for leaf in line.leaves:
+ if leaf.type == token.COLON:
+ in_return_type = False
+ if in_return_type:
+ return_type_leaves.append(leaf)
+ if leaf.type == token.RARROW:
+ in_return_type = True
+
+ # using `bracket_split_build_line` will mess with whitespace, so we duplicate a
+ # couple lines from it.
+ result = Line(mode=line.mode, depth=line.depth)
+ leaves_to_track = get_leaves_inside_matching_brackets(return_type_leaves)
+ for leaf in return_type_leaves:
+ result.append(
+ leaf,
+ preformatted=True,
+ track_bracket=id(leaf) in leaves_to_track,
+ )
+
+ # we could also return true if the line is too long, and the return type is longer
+ # than the param list. Or if `should_split_rhs` returns True.
+ return result.magic_trailing_comma is not None
+
+
class _BracketSplitComponent(Enum):
head = auto()
body = auto()
tail = auto()
-def left_hand_split(line: Line, _features: Collection[Feature] = ()) -> Iterator[Line]:
+def left_hand_split(
+ line: Line, _features: Collection[Feature], mode: Mode
+) -> 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.
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:
break
leaves_to_track: Set[LeafID] = set()
- if (
- Preview.handle_trailing_commas_in_head in original.mode
- and component is _BracketSplitComponent.head
- ):
+ if component is _BracketSplitComponent.head:
leaves_to_track = get_leaves_inside_matching_brackets(leaves)
# Populate the line
for leaf in leaves:
"""
@wraps(split_func)
- def split_wrapper(line: Line, features: Collection[Feature] = ()) -> Iterator[Line]:
- for split_line in split_func(line, features):
+ def split_wrapper(
+ line: Line, features: Collection[Feature], mode: Mode
+ ) -> Iterator[Line]:
+ for split_line in split_func(line, features, mode):
normalize_prefix(split_line.leaves[0], inside_brackets=True)
yield split_line
return split_wrapper
+def _get_last_non_comment_leaf(line: Line) -> Optional[int]:
+ for leaf_idx in range(len(line.leaves) - 1, 0, -1):
+ if line.leaves[leaf_idx].type != STANDALONE_COMMENT:
+ return leaf_idx
+ return None
+
+
+def _safe_add_trailing_comma(safe: bool, delimiter_priority: int, line: Line) -> Line:
+ if (
+ safe
+ and delimiter_priority == COMMA_PRIORITY
+ and line.leaves[-1].type != token.COMMA
+ and line.leaves[-1].type != STANDALONE_COMMENT
+ ):
+ new_comma = Leaf(token.COMMA, ",")
+ line.append(new_comma)
+ return line
+
+
@dont_increase_indentation
-def delimiter_split(line: Line, features: Collection[Feature] = ()) -> Iterator[Line]:
+def delimiter_split(
+ line: Line, features: Collection[Feature], mode: Mode
+) -> Iterator[Line]:
"""Split according to delimiters of the highest priority.
If the appropriate Features are given, the split will add trailing commas
)
current_line.append(leaf)
- for leaf in line.leaves:
+ last_non_comment_leaf = _get_last_non_comment_leaf(line)
+ for leaf_idx, leaf in enumerate(line.leaves):
yield from append_to_line(leaf)
for comment_after in line.comments_after(leaf):
trailing_comma_safe and Feature.TRAILING_COMMA_IN_CALL in features
)
+ if (
+ Preview.add_trailing_comma_consistently in mode
+ and last_leaf.type == STANDALONE_COMMENT
+ and leaf_idx == last_non_comment_leaf
+ ):
+ current_line = _safe_add_trailing_comma(
+ trailing_comma_safe, delimiter_priority, current_line
+ )
+
leaf_priority = bt.delimiters.get(id(leaf))
if leaf_priority == delimiter_priority:
yield current_line
mode=line.mode, 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
- ):
- new_comma = Leaf(token.COMMA, ",")
- current_line.append(new_comma)
+ current_line = _safe_add_trailing_comma(
+ trailing_comma_safe, delimiter_priority, current_line
+ )
yield current_line
@dont_increase_indentation
def standalone_comment_split(
- line: Line, features: Collection[Feature] = ()
+ line: Line, features: Collection[Feature], mode: Mode
) -> Iterator[Line]:
"""Split standalone comments from the rest of the line."""
if not line.contains_standalone_comments(0):
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, preview=mode.preview):
+ 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
if check_lpar:
if (
- mode.preview
- and child.type == syms.atom
+ child.type == syms.atom
and node.type == syms.for_stmt
and isinstance(child.prev_sibling, Leaf)
and child.prev_sibling.type == token.NAME
remove_brackets_around_comma=True,
):
wrap_in_parentheses(node, child, visible=False)
- elif (
- mode.preview and isinstance(child, Node) and node.type == syms.with_stmt
- ):
+ elif isinstance(child, Node) and node.type == syms.with_stmt:
remove_with_parens(child, node)
elif child.type == syms.atom:
if maybe_make_parens_invisible_in_atom(
elif not (isinstance(child, Leaf) and is_multiline_string(child)):
wrap_in_parentheses(node, child, visible=False)
- comma_check = child.type == token.COMMA if mode.preview else False
+ comma_check = child.type == token.COMMA
check_lpar = isinstance(child, Leaf) and (
child.value in parens_after or comma_check
Returns whether the node should itself be wrapped in invisible parentheses.
"""
if (
- node.type != syms.atom
+ node.type not in (syms.atom, syms.expr)
or is_empty_tuple(node)
or is_one_tuple(node)
or (is_yield(node) and parent.type != syms.expr_stmt)
syms.except_clause,
syms.funcdef,
syms.with_stmt,
+ syms.tname,
# these ones aren't useful to end users, but they do please fuzzers
syms.for_stmt,
syms.del_stmt,
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,
if not line_str:
line_str = line_to_string(line)
result: List[Line] = []
- for transformed_line in transform(line, features):
+ for transformed_line in transform(line, features, mode):
if str(transformed_line).strip("\n") == line_str:
raise CannotTransform("Line transformer returned an unchanged result")
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
projects / etc / vim.git / blobdiff