"""
Generating lines of code.
"""
-from functools import partial, wraps
import sys
-from typing import Collection, Iterator, List, Optional, Set, Union
-
-from dataclasses import dataclass, field
-
-from black.nodes import WHITESPACE, RARROW, STATEMENT, STANDALONE_COMMENT
-from black.nodes import ASSIGNMENTS, OPENING_BRACKETS, CLOSING_BRACKETS
-from black.nodes import Visitor, syms, first_child_is_arith, ensure_visible
-from black.nodes import is_docstring, is_empty_tuple, is_one_tuple, is_one_tuple_between
-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 functools import partial, wraps
+from typing import Collection, Iterator, List, Optional, Set, Union, cast
+
+from black.brackets import COMMA_PRIORITY, DOT_PRIORITY, 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_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.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
-from black.trans import StringSplitter, StringParenWrapper, StringParenStripper
-from black.mode import Mode
-from black.mode import Feature
-
-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
"""A readable split that fits the allotted line length is impossible."""
-@dataclass
+# This isn't a dataclass because @dataclass + Generic breaks mypyc.
+# See also https://github.com/mypyc/mypyc/issues/827.
class LineGenerator(Visitor[Line]):
"""Generates reformatted Line objects. Empty lines are not emitted.
in ways that will no longer stringify to valid Python code on the tree.
"""
- mode: Mode
- remove_u_prefix: bool = False
- current_line: Line = field(init=False)
+ def __init__(self, mode: Mode) -> None:
+ self.mode = mode
+ self.current_line: Line
+ self.__post_init__()
def line(self, indent: int = 0) -> Iterator[Line]:
"""Generate a 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):
+ for comment in generate_comments(node, preview=self.mode.preview):
if any_open_brackets:
# any comment within brackets is subject to splitting
self.current_line.append(comment)
normalize_prefix(node, inside_brackets=any_open_brackets)
if self.mode.string_normalization and node.type == token.STRING:
- node.value = normalize_string_prefix(
- node.value, remove_u_prefix=self.remove_u_prefix
- )
+ node.value = normalize_string_prefix(node.value)
node.value = normalize_string_quotes(node.value)
if node.type == token.NUMBER:
normalize_numeric_literal(node)
"""Visit a statement.
This implementation is shared for `if`, `while`, `for`, `try`, `except`,
- `def`, `with`, `class`, `assert`, `match`, `case` and assignments.
+ `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)
+ normalize_invisible_parens(node, parens_after=parens, preview=self.mode.preview)
for child in node.children:
- if child.type == token.NAME and child.value in keywords: # type: ignore
+ if is_name_token(child) and child.value in keywords:
yield from self.line()
yield from self.visit(child)
+ 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()
+
+ # 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:
+ wrap_in_parentheses(node, child, visible=False)
+ is_return_annotation = False
+
+ 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."""
+ normalize_invisible_parens(node, parens_after=set(), preview=self.mode.preview)
+
+ yield from self.line()
+ for child in node.children:
+ yield from self.visit(child)
+
def visit_suite(self, node: Node) -> Iterator[Line]:
"""Visit a suite."""
if self.mode.is_pyi and is_stub_suite(node):
def visit_simple_stmt(self, node: Node) -> Iterator[Line]:
"""Visit a statement without nested statements."""
- if first_child_is_arith(node):
- wrap_in_parentheses(node, node.children[0], visible=False)
+ prev_type: Optional[int] = None
+ for child in node.children:
+ if (prev_type is None or prev_type == token.SEMI) and is_arith_like(child):
+ wrap_in_parentheses(node, child, visible=False)
+ prev_type = child.type
+
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):
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)
yield from self.line()
yield from self.visit(child)
+ def visit_power(self, node: Node) -> Iterator[Line]:
+ for idx, leaf in enumerate(node.children[:-1]):
+ next_leaf = node.children[idx + 1]
+
+ if not isinstance(leaf, Leaf):
+ continue
+
+ value = leaf.value.lower()
+ if (
+ leaf.type == token.NUMBER
+ and next_leaf.type == syms.trailer
+ # Ensure that we are in an attribute trailer
+ and next_leaf.children[0].type == token.DOT
+ # It shouldn't wrap hexadecimal, binary and octal literals
+ and not value.startswith(("0x", "0b", "0o"))
+ # It shouldn't wrap complex literals
+ and "j" not in value
+ ):
+ wrap_in_parentheses(node, leaf)
+
+ if Preview.remove_redundant_parens in self.mode:
+ remove_await_parens(node)
+
+ yield from self.visit_default(node)
+
def visit_SEMI(self, leaf: Leaf) -> Iterator[Line]:
"""Remove a semicolon and put the other statement on a separate line."""
yield from self.line()
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, self.remove_u_prefix)
+ 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, then we need to add the length
+ # of the indent, prefix, and starting quotes. Ending quotes are
+ # handled later.
+ lines = docstring.splitlines()
+ last_line_length = len(lines[-1]) if docstring else 0
+
+ if len(lines) == 1:
+ last_line_length += len(indent) + len(prefix) + quote_len
+
+ # 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 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)
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)
+ 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_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_decorated = self.visit_decorators
# PEP 634
- self.visit_match_stmt = partial(v, keywords={"match"}, parens=Ø)
- self.visit_case_block = partial(v, keywords={"case"}, parens=Ø)
+ self.visit_match_stmt = self.visit_match_case
+ self.visit_case_block = self.visit_match_case
def transform_line(
and not (line.inside_brackets and line.contains_standalone_comments())
):
# Only apply basic string preprocessing, since lines shouldn't be split here.
- if mode.experimental_string_processing:
+ if Preview.string_processing in mode:
transformers = [string_merge, string_paren_strip]
else:
transformers = []
transformers = [left_hand_split]
else:
- def rhs(line: Line, features: Collection[Feature]) -> Iterator[Line]:
+ def _rhs(
+ self: object, line: Line, features: Collection[Feature]
+ ) -> Iterator[Line]:
"""Wraps calls to `right_hand_split`.
The calls increasingly `omit` right-hand trailers (bracket pairs with
line, line_length=mode.line_length, features=features
)
- if mode.experimental_string_processing:
+ # HACK: nested functions (like _rhs) compiled by mypyc don't retain their
+ # __name__ attribute which is needed in `run_transformer` further down.
+ # Unfortunately a nested class breaks mypyc too. So a class must be created
+ # via type ... https://github.com/mypyc/mypyc/issues/884
+ rhs = type("rhs", (), {"__call__": _rhs})()
+
+ if Preview.string_processing in mode:
if line.inside_brackets:
transformers = [
string_merge,
transformers = [delimiter_split, standalone_comment_split, rhs]
else:
transformers = [rhs]
+ # It's always safe to attempt hugging of power operations and pretty much every line
+ # could match.
+ transformers.append(hug_power_op)
for transform in transformers:
# We are accumulating lines in `result` because we might want to abort
current_leaves is body_leaves
and leaf.type in CLOSING_BRACKETS
and leaf.opening_bracket is matching_bracket
+ and isinstance(matching_bracket, Leaf)
):
+ ensure_visible(leaf)
+ ensure_visible(matching_bracket)
current_leaves = tail_leaves if body_leaves else head_leaves
current_leaves.append(leaf)
if current_leaves is head_leaves:
# 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_on_explode=omit)
+ and can_omit_invisible_parens(body, line_length)
):
omit = {id(closing_bracket), *omit}
try:
@wraps(split_func)
def split_wrapper(line: Line, features: Collection[Feature] = ()) -> Iterator[Line]:
- for line in split_func(line, features):
- normalize_prefix(line.leaves[0], inside_brackets=True)
- yield line
+ for split_line in split_func(line, features):
+ normalize_prefix(split_line.leaves[0], inside_brackets=True)
+ yield split_line
return split_wrapper
leaf.prefix = ""
-def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None:
+def normalize_invisible_parens(
+ node: Node, parens_after: Set[str], *, preview: bool
+) -> None:
"""Make existing optional parentheses invisible or create new ones.
`parens_after` is a set of string leaf values immediately after which parens
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):
+ for pc in list_comments(node.prefix, is_endmarker=False, preview=preview):
if pc.value in FMT_OFF:
# This `node` has a prefix with `# fmt: off`, don't mess with parens.
return
# Fixes a bug where invisible parens are not properly stripped from
# assignment statements that contain type annotations.
if isinstance(child, Node) and child.type == syms.annassign:
- normalize_invisible_parens(child, parens_after=parens_after)
+ normalize_invisible_parens(
+ child, parens_after=parens_after, preview=preview
+ )
# Add parentheses around long tuple unpacking in assignments.
if (
check_lpar = True
if check_lpar:
- if child.type == syms.atom:
- if maybe_make_parens_invisible_in_atom(child, parent=node):
+ if (
+ preview
+ and child.type == syms.atom
+ and node.type == syms.for_stmt
+ and isinstance(child.prev_sibling, Leaf)
+ and child.prev_sibling.type == token.NAME
+ and child.prev_sibling.value == "for"
+ ):
+ if maybe_make_parens_invisible_in_atom(
+ child,
+ parent=node,
+ remove_brackets_around_comma=True,
+ ):
+ wrap_in_parentheses(node, child, visible=False)
+ elif preview and 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(
+ child,
+ parent=node,
+ ):
wrap_in_parentheses(node, child, visible=False)
elif is_one_tuple(child):
wrap_in_parentheses(node, child, visible=True)
elif node.type == syms.import_from:
# "import from" nodes store parentheses directly as part of
# the statement
- if child.type == token.LPAR:
+ if is_lpar_token(child):
+ assert is_rpar_token(node.children[-1])
# make parentheses invisible
- child.value = "" # type: ignore
- node.children[-1].value = "" # type: ignore
+ child.value = ""
+ node.children[-1].value = ""
elif child.type != token.STAR:
# insert invisible parentheses
node.insert_child(index, Leaf(token.LPAR, ""))
node.append_child(Leaf(token.RPAR, ""))
break
+ elif (
+ index == 1
+ and child.type == token.STAR
+ and node.type == syms.except_clause
+ ):
+ # In except* (PEP 654), the star is actually part of
+ # of the keyword. So we need to skip the insertion of
+ # invisible parentheses to work more precisely.
+ continue
elif not (isinstance(child, Leaf) and is_multiline_string(child)):
wrap_in_parentheses(node, child, visible=False)
- check_lpar = isinstance(child, Leaf) and child.value in parens_after
+ comma_check = child.type == token.COMMA if preview else False
+
+ check_lpar = isinstance(child, Leaf) and (
+ child.value in parens_after or comma_check
+ )
-def maybe_make_parens_invisible_in_atom(node: LN, parent: LN) -> bool:
+def remove_await_parens(node: Node) -> None:
+ if node.children[0].type == token.AWAIT and len(node.children) > 1:
+ if (
+ node.children[1].type == syms.atom
+ and node.children[1].children[0].type == token.LPAR
+ ):
+ if maybe_make_parens_invisible_in_atom(
+ node.children[1],
+ parent=node,
+ remove_brackets_around_comma=True,
+ ):
+ wrap_in_parentheses(node, node.children[1], visible=False)
+
+ # Since await is an expression we shouldn't remove
+ # brackets in cases where this would change
+ # the AST due to operator precedence.
+ # Therefore we only aim to remove brackets around
+ # power nodes that aren't also await expressions themselves.
+ # https://peps.python.org/pep-0492/#updated-operator-precedence-table
+ # N.B. We've still removed any redundant nested brackets though :)
+ opening_bracket = cast(Leaf, node.children[1].children[0])
+ closing_bracket = cast(Leaf, node.children[1].children[-1])
+ bracket_contents = cast(Node, node.children[1].children[1])
+ if bracket_contents.type != syms.power:
+ ensure_visible(opening_bracket)
+ ensure_visible(closing_bracket)
+ elif (
+ bracket_contents.type == syms.power
+ and bracket_contents.children[0].type == token.AWAIT
+ ):
+ ensure_visible(opening_bracket)
+ ensure_visible(closing_bracket)
+ # If we are in a nested await then recurse down.
+ remove_await_parens(bracket_contents)
+
+
+def remove_with_parens(node: Node, parent: Node) -> None:
+ """Recursively hide optional parens in `with` statements."""
+ # Removing all unnecessary parentheses in with statements in one pass is a tad
+ # complex as different variations of bracketed statements result in pretty
+ # different parse trees:
+ #
+ # with (open("file")) as f: # this is an asexpr_test
+ # ...
+ #
+ # with (open("file") as f): # this is an atom containing an
+ # ... # asexpr_test
+ #
+ # with (open("file")) as f, (open("file")) as f: # this is asexpr_test, COMMA,
+ # ... # asexpr_test
+ #
+ # with (open("file") as f, open("file") as f): # an atom containing a
+ # ... # testlist_gexp which then
+ # # contains multiple asexpr_test(s)
+ if node.type == syms.atom:
+ if maybe_make_parens_invisible_in_atom(
+ node,
+ parent=parent,
+ remove_brackets_around_comma=True,
+ ):
+ wrap_in_parentheses(parent, node, visible=False)
+ if isinstance(node.children[1], Node):
+ remove_with_parens(node.children[1], node)
+ elif node.type == syms.testlist_gexp:
+ for child in node.children:
+ if isinstance(child, Node):
+ remove_with_parens(child, node)
+ elif node.type == syms.asexpr_test and not any(
+ leaf.type == token.COLONEQUAL for leaf in node.leaves()
+ ):
+ if maybe_make_parens_invisible_in_atom(
+ node.children[0],
+ parent=node,
+ remove_brackets_around_comma=True,
+ ):
+ wrap_in_parentheses(node, node.children[0], visible=False)
+
+
+def maybe_make_parens_invisible_in_atom(
+ node: LN,
+ parent: LN,
+ remove_brackets_around_comma: bool = False,
+) -> 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
+ or (
+ # This condition tries to prevent removing non-optional brackets
+ # around a tuple, however, can be a bit overzealous so we provide
+ # and option to skip this check for `for` and `with` statements.
+ not remove_brackets_around_comma
+ and 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:
+ if is_lpar_token(first) and is_rpar_token(last):
middle = node.children[1]
# make parentheses invisible
- first.value = "" # type: ignore
- last.value = "" # type: ignore
- maybe_make_parens_invisible_in_atom(middle, parent=parent)
+ first.value = ""
+ last.value = ""
+ maybe_make_parens_invisible_in_atom(
+ middle,
+ parent=parent,
+ remove_brackets_around_comma=remove_brackets_around_comma,
+ )
if is_atom_with_invisible_parens(middle):
# Strip the invisible parens from `middle` by replacing
if (
prev
and prev.type == token.COMMA
- and not is_one_tuple_between(
+ and leaf.opening_bracket is not None
+ and not is_one_sequence_between(
leaf.opening_bracket, leaf, line.leaves
)
):
if (
prev
and prev.type == token.COMMA
- and not is_one_tuple_between(leaf.opening_bracket, leaf, line.leaves)
+ and leaf.opening_bracket is not None
+ and not is_one_sequence_between(leaf.opening_bracket, leaf, line.leaves)
):
# Never omit bracket pairs with trailing commas.
# We need to explode on those.
result.extend(transform_line(transformed_line, mode=mode, features=features))
if (
- transform.__name__ != "rhs"
+ transform.__class__.__name__ != "rhs"
or not line.bracket_tracker.invisible
or any(bracket.value for bracket in line.bracket_tracker.invisible)
or line.contains_multiline_strings()
projects / etc / vim.git / blobdiff