X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/00e7e12a3a412ea386806d5d4eeaed345e912940..84851914488b2f3f6388a0760ee04306e4c2fc18:/src/black/linegen.py diff --git a/src/black/linegen.py b/src/black/linegen.py index 3b811f0..f234913 100644 --- a/src/black/linegen.py +++ b/src/black/linegen.py @@ -5,9 +5,7 @@ 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, STATEMENT, STANDALONE_COMMENT +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 @@ -40,7 +38,8 @@ class CannotSplit(CannotTransform): """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. @@ -48,9 +47,11 @@ class LineGenerator(Visitor[Line]): 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, remove_u_prefix: bool = False) -> None: + self.mode = mode + self.remove_u_prefix = remove_u_prefix + self.current_line: Line + self.__post_init__() def line(self, indent: int = 0) -> Iterator[Line]: """Generate a line. @@ -126,7 +127,7 @@ class LineGenerator(Visitor[Line]): """Visit a statement. This implementation is shared for `if`, `while`, `for`, `try`, `except`, - `def`, `with`, `class`, `assert` 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. @@ -141,6 +142,14 @@ class LineGenerator(Visitor[Line]): 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()) + + 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): @@ -292,6 +301,10 @@ class LineGenerator(Visitor[Line]): self.visit_async_funcdef = self.visit_async_stmt self.visit_decorated = self.visit_decorators + # PEP 634 + self.visit_match_stmt = self.visit_match_case + self.visit_case_block = self.visit_match_case + def transform_line( line: Line, mode: Mode, features: Collection[Feature] = () @@ -335,7 +348,9 @@ def transform_line( 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 @@ -362,6 +377,12 @@ def transform_line( line, line_length=mode.line_length, features=features ) + # 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 mode.experimental_string_processing: if line.inside_brackets: transformers = [ @@ -503,14 +524,14 @@ def right_hand_split( yield from right_hand_split(line, line_length, features=features, omit=omit) return - except CannotSplit: + except CannotSplit as e: 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." - ) + ) from e elif head.contains_multiline_strings() or tail.contains_multiline_strings(): raise CannotSplit( @@ -518,7 +539,7 @@ def right_hand_split( " satisfy the splitting algorithm because the head or the tail" " contains multiline strings which by definition never fit one" " line." - ) + ) from e ensure_visible(opening_bracket) ensure_visible(closing_bracket) @@ -574,6 +595,20 @@ def bracket_split_build_line( original.is_def and opening_bracket.value == "(" and not any(leaf.type == token.COMMA for leaf in leaves) + # In particular, don't add one within a parenthesized return annotation. + # Unfortunately the indicator we're in a return annotation (RARROW) may + # be defined directly in the parent node, the parent of the parent ... + # and so on depending on how complex the return annotation is. + # This isn't perfect and there's some false negatives but they are in + # contexts were a comma is actually fine. + and not any( + node.prev_sibling.type == RARROW + for node in ( + leaves[0].parent, + getattr(leaves[0].parent, "parent", None), + ) + if isinstance(node, Node) and isinstance(node.prev_sibling, Leaf) + ) ) if original.is_import or no_commas: @@ -621,13 +656,13 @@ def delimiter_split(line: Line, features: Collection[Feature] = ()) -> Iterator[ try: last_leaf = line.leaves[-1] except IndexError: - raise CannotSplit("Line empty") + raise CannotSplit("Line empty") from None bt = line.bracket_tracker try: delimiter_priority = bt.max_delimiter_priority(exclude={id(last_leaf)}) except ValueError: - raise CannotSplit("No delimiters found") + raise CannotSplit("No delimiters found") from None if delimiter_priority == DOT_PRIORITY: if bt.delimiter_count_with_priority(delimiter_priority) == 1: @@ -961,14 +996,19 @@ def run_transformer( result.extend(transform_line(transformed_line, mode=mode, features=features)) - if not ( - transform.__name__ == "rhs" - and line.bracket_tracker.invisible - and not any(bracket.value for bracket in line.bracket_tracker.invisible) - and not line.contains_multiline_strings() - and not result[0].contains_uncollapsable_type_comments() - and not result[0].contains_unsplittable_type_ignore() - and not is_line_short_enough(result[0], line_length=mode.line_length) + if ( + 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() + 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) + # 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 + # call to `append_leaves()` to fail. + or any(leaf.parent is None for leaf in line.leaves) ): return result