"""
Generating lines of code.
"""
-from functools import partial, wraps
import sys
+from enum import Enum, auto
+from functools import partial, wraps
from typing import Collection, Iterator, List, Optional, Set, Union, cast
-from black.nodes import WHITESPACE, RARROW, STATEMENT, STANDALONE_COMMENT
-from black.nodes import ASSIGNMENTS, OPENING_BRACKETS, CLOSING_BRACKETS
-from black.nodes import Visitor, syms, is_arith_like, ensure_visible
+from black.brackets import (
+ COMMA_PRIORITY,
+ DOT_PRIORITY,
+ get_leaves_inside_matching_brackets,
+ max_delimiter_priority_in_atom,
+)
+from black.comments import FMT_OFF, generate_comments, list_comments
+from black.lines import (
+ Line,
+ append_leaves,
+ can_be_split,
+ can_omit_invisible_parens,
+ is_line_short_enough,
+ line_to_string,
+)
+from black.mode import Feature, Mode, Preview
from black.nodes import (
+ ASSIGNMENTS,
+ CLOSING_BRACKETS,
+ OPENING_BRACKETS,
+ RARROW,
+ STANDALONE_COMMENT,
+ STATEMENT,
+ WHITESPACE,
+ Visitor,
+ ensure_visible,
+ is_arith_like,
+ is_atom_with_invisible_parens,
is_docstring,
is_empty_tuple,
- is_one_tuple,
+ is_lpar_token,
+ is_multiline_string,
+ is_name_token,
is_one_sequence_between,
+ is_one_tuple,
+ is_rpar_token,
+ is_stub_body,
+ is_stub_suite,
+ is_vararg,
+ is_walrus_assignment,
+ is_yield,
+ syms,
+ wrap_in_parentheses,
)
-from black.nodes import is_name_token, is_lpar_token, is_rpar_token
-from black.nodes import is_walrus_assignment, is_yield, is_vararg, is_multiline_string
-from black.nodes import is_stub_suite, is_stub_body, is_atom_with_invisible_parens
-from black.nodes import wrap_in_parentheses
-from black.brackets import max_delimiter_priority_in_atom
-from black.brackets import DOT_PRIORITY, COMMA_PRIORITY
-from black.lines import Line, line_to_string, is_line_short_enough
-from black.lines import can_omit_invisible_parens, can_be_split, append_leaves
-from black.comments import generate_comments, list_comments, FMT_OFF
from black.numerics import normalize_numeric_literal
-from black.strings import get_string_prefix, fix_docstring
-from black.strings import normalize_string_prefix, normalize_string_quotes
-from black.trans import Transformer, CannotTransform, StringMerger, StringSplitter
-from black.trans import StringParenWrapper, StringParenStripper, hug_power_op
-from black.mode import Mode, Feature, Preview
-
-from blib2to3.pytree import Node, Leaf
+from black.strings import (
+ fix_docstring,
+ get_string_prefix,
+ normalize_string_prefix,
+ normalize_string_quotes,
+)
+from black.trans import (
+ CannotTransform,
+ StringMerger,
+ StringParenStripper,
+ StringParenWrapper,
+ StringSplitter,
+ Transformer,
+ hug_power_op,
+)
from blib2to3.pgen2 import token
-
+from blib2to3.pytree import Leaf, Node
# types
LeafID = int
for child in children:
yield from self.visit(child)
- if child.type == token.ASYNC:
+ if child.type == token.ASYNC or child.type == STANDALONE_COMMENT:
+ # STANDALONE_COMMENT happens when `# fmt: skip` is applied on the async
+ # line.
break
internal_stmt = next(children)
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.
- docstring = normalize_string_prefix(leaf.value)
+ 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 >.<
+ docstring = normalize_string_prefix(leaf.value)
prefix = get_string_prefix(docstring)
docstring = docstring[len(prefix) :] # Remove the prefix
quote_char = docstring[0]
quote_len = 1 if docstring[1] != quote_char else 3
docstring = docstring[quote_len:-quote_len]
docstring_started_empty = not docstring
+ indent = " " * 4 * self.current_line.depth
if is_multiline_string(leaf):
- indent = " " * 4 * self.current_line.depth
docstring = fix_docstring(docstring, indent)
else:
docstring = docstring.strip()
# We could enforce triple quotes at this point.
quote = quote_char * quote_len
- leaf.value = prefix + quote + docstring + quote
+
+ # 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:
+ # 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.
+ # If docstring is one line, we don't put the closing quotes on a
+ # separate line because it looks ugly (#3320).
+ lines = docstring.splitlines()
+ last_line_length = len(lines[-1]) if docstring else 0
+
+ # If adding closing quotes would cause the last line to exceed
+ # the maximum line length then put a line break before the
+ # closing quotes
+ if (
+ len(lines) > 1
+ and last_line_length + quote_len > self.mode.line_length
+ ):
+ leaf.value = prefix + quote + docstring + "\n" + indent + quote
+ else:
+ leaf.value = prefix + quote + docstring + quote
+ else:
+ leaf.value = prefix + quote + docstring + quote
yield from self.visit_default(leaf)
yield line
+class _BracketSplitComponent(Enum):
+ head = auto()
+ body = auto()
+ tail = auto()
+
+
def left_hand_split(line: Line, _features: Collection[Feature] = ()) -> Iterator[Line]:
"""Split line into many lines, starting with the first matching bracket pair.
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)
+ head = bracket_split_build_line(
+ head_leaves, line, matching_bracket, component=_BracketSplitComponent.head
+ )
+ body = bracket_split_build_line(
+ body_leaves, line, matching_bracket, component=_BracketSplitComponent.body
+ )
+ tail = bracket_split_build_line(
+ tail_leaves, line, matching_bracket, component=_BracketSplitComponent.tail
+ )
bracket_split_succeeded_or_raise(head, body, tail)
for result in (head, body, tail):
if result:
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)
+ head = bracket_split_build_line(
+ head_leaves, line, opening_bracket, component=_BracketSplitComponent.head
+ )
+ body = bracket_split_build_line(
+ body_leaves, line, opening_bracket, component=_BracketSplitComponent.body
+ )
+ tail = bracket_split_build_line(
+ tail_leaves, line, opening_bracket, component=_BracketSplitComponent.tail
+ )
bracket_split_succeeded_or_raise(head, body, tail)
if (
Feature.FORCE_OPTIONAL_PARENTHESES not in features
def bracket_split_build_line(
- leaves: List[Leaf], original: Line, opening_bracket: Leaf, *, is_body: bool = False
+ leaves: List[Leaf],
+ original: Line,
+ opening_bracket: Leaf,
+ *,
+ component: _BracketSplitComponent,
) -> 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.
+ If it's the head component, brackets will be tracked so trailing commas are
+ respected.
+
+ If it's the body component, 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(mode=original.mode, depth=original.depth)
- if is_body:
+ if component is _BracketSplitComponent.body:
result.inside_brackets = True
result.depth += 1
if leaves:
leaves.insert(i + 1, new_comma)
break
+ leaves_to_track: Set[LeafID] = set()
+ if (
+ Preview.handle_trailing_commas_in_head in original.mode
+ and component is _BracketSplitComponent.head
+ ):
+ leaves_to_track = get_leaves_inside_matching_brackets(leaves)
# Populate the line
for leaf in leaves:
- result.append(leaf, preformatted=True)
+ result.append(
+ leaf,
+ preformatted=True,
+ track_bracket=id(leaf) in leaves_to_track,
+ )
for comment_after in original.comments_after(leaf):
result.append(comment_after, preformatted=True)
- if is_body and should_split_line(result, opening_bracket):
+ if component is _BracketSplitComponent.body and should_split_line(
+ result, opening_bracket
+ ):
result.should_split_rhs = True
return result