X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/dd4477b70120bf736144c38ec50144253f34dce2..9a6c88c7f4b4db14631f8dc9e8d44b3aed9d57c9:/black.py?ds=sidebyside diff --git a/black.py b/black.py index c48b8d1..afc37d9 100644 --- a/black.py +++ b/black.py @@ -30,6 +30,7 @@ from typing import ( Type, TypeVar, Union, + cast, ) from appdirs import user_cache_dir @@ -43,11 +44,12 @@ from blib2to3.pgen2 import driver, token from blib2to3.pgen2.parse import ParseError -__version__ = "18.4a6" +__version__ = "18.5b0" DEFAULT_LINE_LENGTH = 88 +CACHE_DIR = Path(user_cache_dir("black", version=__version__)) + # types -syms = pygram.python_symbols FileContent = str Encoding = str Depth = int @@ -64,6 +66,9 @@ Cache = Dict[Path, CacheInfo] out = partial(click.secho, bold=True, err=True) err = partial(click.secho, fg="red", err=True) +pygram.initialize(CACHE_DIR) +syms = pygram.python_symbols + class NothingChanged(UserWarning): """Raised by :func:`format_file` when reformatted code is the same as source.""" @@ -1370,32 +1375,6 @@ class LineGenerator(Visitor[Line]): yield from self.line() yield from self.visit(child) - def visit_import_from(self, node: Node) -> Iterator[Line]: - """Visit import_from and maybe put invisible parentheses. - - This is separate from `visit_stmt` because import statements don't - support arbitrary atoms and thus handling of parentheses is custom. - """ - check_lpar = False - for index, child in enumerate(node.children): - if check_lpar: - if child.type == token.LPAR: - # make parentheses invisible - child.value = "" # type: ignore - node.children[-1].value = "" # type: ignore - else: - # insert invisible parentheses - node.insert_child(index, Leaf(token.LPAR, "")) - node.append_child(Leaf(token.RPAR, "")) - break - - check_lpar = ( - child.type == token.NAME and child.value == "import" # type: ignore - ) - - for child in node.children: - yield from self.visit(child) - def visit_SEMI(self, leaf: Leaf) -> Iterator[Line]: """Remove a semicolon and put the other statement on a separate line.""" yield from self.line() @@ -1442,6 +1421,7 @@ class LineGenerator(Visitor[Line]): 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_import_from = partial(v, keywords=Ø, parens={"import"}) self.visit_async_funcdef = self.visit_async_stmt self.visit_decorated = self.visit_decorators @@ -1741,7 +1721,7 @@ def is_split_before_delimiter(leaf: Leaf, previous: Leaf = None) -> int: leaf.type == token.DOT and leaf.parent and leaf.parent.type not in {syms.import_from, syms.dotted_name} - and (previous is None or previous.type != token.NAME) + and (previous is None or previous.type in CLOSING_BRACKETS) ): return DOT_PRIORITY @@ -1815,7 +1795,7 @@ def is_split_before_delimiter(leaf: Leaf, previous: Leaf = None) -> int: return 0 -def generate_comments(leaf: Leaf) -> Iterator[Leaf]: +def generate_comments(leaf: LN) -> Iterator[Leaf]: """Clean the prefix of the `leaf` and generate comments from it, if any. Comments in lib2to3 are shoved into the whitespace prefix. This happens @@ -1922,12 +1902,14 @@ def split_line( def rhs(line: Line, py36: bool = False) -> Iterator[Line]: for omit in generate_trailers_to_omit(line, line_length): - lines = list(right_hand_split(line, py36, omit=omit)) + lines = list(right_hand_split(line, line_length, py36, omit=omit)) if is_line_short_enough(lines[0], line_length=line_length): yield from lines return # All splits failed, best effort split with no omits. + # This mostly happens to multiline strings that are by definition + # reported as not fitting a single line. yield from right_hand_split(line, py36) if line.inside_brackets: @@ -2001,7 +1983,7 @@ def left_hand_split(line: Line, py36: bool = False) -> Iterator[Line]: def right_hand_split( - line: Line, py36: bool = False, omit: Collection[LeafID] = () + line: Line, line_length: int, py36: bool = False, omit: Collection[LeafID] = () ) -> Iterator[Line]: """Split line into many lines, starting with the last matching bracket pair. @@ -2063,17 +2045,9 @@ def right_hand_split( and not line.is_import ): omit = {id(closing_bracket), *omit} - delimiter_count = body.bracket_tracker.delimiter_count_with_priority() - if ( - delimiter_count == 0 - or delimiter_count == 1 - and ( - body.leaves[0].type in OPENING_BRACKETS - or body.leaves[-1].type in CLOSING_BRACKETS - ) - ): + if can_omit_invisible_parens(body, line_length): try: - yield from right_hand_split(line, py36=py36, omit=omit) + yield from right_hand_split(line, line_length, py36=py36, omit=omit) return except CannotSplit: pass @@ -2338,8 +2312,13 @@ def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None: Standardizes on visible parentheses for single-element tuples, and keeps existing visible parentheses for other tuples and generator expressions. """ + try: + list(generate_comments(node)) + except FormatOff: + return # This `node` has a prefix with `# fmt: off`, don't mess with parens. + check_lpar = False - for child in list(node.children): + for index, child in enumerate(list(node.children)): if check_lpar: if child.type == syms.atom: maybe_make_parens_invisible_in_atom(child) @@ -2347,8 +2326,21 @@ def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None: # wrap child in visible parentheses lpar = Leaf(token.LPAR, "(") rpar = Leaf(token.RPAR, ")") - index = child.remove() or 0 + child.remove() node.insert_child(index, Node(syms.atom, [lpar, child, rpar])) + elif node.type == syms.import_from: + # "import from" nodes store parentheses directly as part of + # the statement + if child.type == token.LPAR: + # make parentheses invisible + child.value = "" # type: ignore + node.children[-1].value = "" # type: ignore + elif child.type != token.STAR: + # insert invisible parentheses + node.insert_child(index, Leaf(token.LPAR, "")) + node.append_child(Leaf(token.RPAR, "")) + break + elif not (isinstance(child, Leaf) and is_multiline_string(child)): # wrap child in invisible parentheses lpar = Leaf(token.LPAR, "") @@ -2537,13 +2529,21 @@ def ensure_visible(leaf: Leaf) -> None: def should_explode(line: Line, opening_bracket: Leaf) -> bool: """Should `line` immediately be split with `delimiter_split()` after RHS?""" - return bool( + if not ( opening_bracket.parent and opening_bracket.parent.type in {syms.atom, syms.import_from} and opening_bracket.value in "[{(" - and line.bracket_tracker.delimiters - and line.bracket_tracker.max_delimiter_priority() == COMMA_PRIORITY - ) + ): + return False + + try: + last_leaf = line.leaves[-1] + exclude = {id(last_leaf)} if last_leaf.type == token.COMMA else set() + max_priority = line.bracket_tracker.max_delimiter_priority(exclude=exclude) + except (IndexError, ValueError): + return False + + return max_priority == COMMA_PRIORITY def is_python36(node: Node) -> bool: @@ -2594,21 +2594,13 @@ def generate_trailers_to_omit(line: Line, line_length: int) -> Iterator[Set[Leaf closing_bracket = None optional_brackets: Set[LeafID] = set() inner_brackets: Set[LeafID] = set() - for index, leaf in enumerate_reversed(line.leaves): - length += len(leaf.prefix) + len(leaf.value) + for index, leaf, leaf_length in enumerate_with_length(line, reversed=True): + length += leaf_length if length > line_length: break - comment: Optional[Leaf] - for comment in line.comments_after(leaf, index): - if "\n" in comment.prefix: - break # Oops, standalone comment! - - length += len(comment.value) - else: - comment = None - if comment is not None: - break # There was a standalone comment, we can't continue. + if leaf.type == STANDALONE_COMMENT: + break optional_brackets.discard(id(leaf)) if opening_bracket: @@ -2930,6 +2922,32 @@ def enumerate_reversed(sequence: Sequence[T]) -> Iterator[Tuple[Index, T]]: index -= 1 +def enumerate_with_length( + line: Line, reversed: bool = False +) -> Iterator[Tuple[Index, Leaf, int]]: + """Return an enumeration of leaves with their length. + + Stops prematurely on multiline strings and standalone comments. + """ + op = cast( + Callable[[Sequence[Leaf]], Iterator[Tuple[Index, Leaf]]], + enumerate_reversed if reversed else enumerate, + ) + for index, leaf in op(line.leaves): + length = len(leaf.prefix) + len(leaf.value) + if "\n" in leaf.value: + return # Multiline strings, we can't continue. + + comment: Optional[Leaf] + for comment in line.comments_after(leaf, index): + if "\n" in comment.prefix: + return # Oops, standalone comment! + + length += len(comment.value) + + yield index, leaf, length + + def is_line_short_enough(line: Line, *, line_length: int, line_str: str = "") -> bool: """Return True if `line` is no longer than `line_length`. @@ -2944,7 +2962,93 @@ def is_line_short_enough(line: Line, *, line_length: int, line_str: str = "") -> ) -CACHE_DIR = Path(user_cache_dir("black", version=__version__)) +def can_omit_invisible_parens(line: Line, line_length: int) -> bool: + """Does `line` have a shape safe to reformat without optional parens around it? + + Returns True for only a subset of potentially nice looking formattings but + the point is to not return false positives that end up producing lines that + are too long. + """ + bt = line.bracket_tracker + if not bt.delimiters: + # Without delimiters the optional parentheses are useless. + return True + + max_priority = bt.max_delimiter_priority() + if bt.delimiter_count_with_priority(max_priority) > 1: + # With more than one delimiter of a kind the optional parentheses read better. + return False + + if max_priority == DOT_PRIORITY: + # A single stranded method call doesn't require optional parentheses. + return True + + assert len(line.leaves) >= 2, "Stranded delimiter" + + first = line.leaves[0] + second = line.leaves[1] + penultimate = line.leaves[-2] + last = line.leaves[-1] + + # With a single delimiter, omit if the expression starts or ends with + # a bracket. + if first.type in OPENING_BRACKETS and second.type not in CLOSING_BRACKETS: + remainder = False + length = 4 * line.depth + for _index, leaf, leaf_length in enumerate_with_length(line): + if leaf.type in CLOSING_BRACKETS and leaf.opening_bracket is first: + remainder = True + if remainder: + length += leaf_length + if length > line_length: + break + + if leaf.type in OPENING_BRACKETS: + # There are brackets we can further split on. + remainder = False + + else: + # checked the entire string and line length wasn't exceeded + if len(line.leaves) == _index + 1: + return True + + # Note: we are not returning False here because a line might have *both* + # a leading opening bracket and a trailing closing bracket. If the + # opening bracket doesn't match our rule, maybe the closing will. + + if ( + last.type == token.RPAR + or last.type == token.RBRACE + or ( + # don't use indexing for omitting optional parentheses; + # it looks weird + last.type == token.RSQB + and last.parent + and last.parent.type != syms.trailer + ) + ): + if penultimate.type in OPENING_BRACKETS: + # Empty brackets don't help. + return False + + if is_multiline_string(first): + # Additional wrapping of a multiline string in this situation is + # unnecessary. + return True + + length = 4 * line.depth + seen_other_brackets = False + for _index, leaf, leaf_length in enumerate_with_length(line): + length += leaf_length + if leaf is last.opening_bracket: + if seen_other_brackets or length <= line_length: + return True + + elif leaf.type in OPENING_BRACKETS: + # There are brackets we can further split on. + seen_other_brackets = True + + return False def get_cache_file(line_length: int) -> Path: