From: Łukasz Langa Date: Fri, 30 Mar 2018 04:06:18 +0000 (-0700) Subject: Remove standalone comment hacks X-Git-Url: https://git.madduck.net/etc/vim.git/commitdiff_plain/c55d08d0b96c8de8bd867ca315e380d9e9d2d7ec?ds=inline;hp=-c Remove standalone comment hacks Now Black properly splits standalone comments within bracketed expressions. They are treated as another type of split instead of being bolted on with whitespace prefixes. A related fix: now multiple comments might appear after a given leaf. Fixes #22 --- c55d08d0b96c8de8bd867ca315e380d9e9d2d7ec diff --git a/black.py b/black.py index dab3f00..6499b22 100644 --- a/black.py +++ b/black.py @@ -3,14 +3,25 @@ import asyncio from asyncio.base_events import BaseEventLoop from concurrent.futures import Executor, ProcessPoolExecutor -from functools import partial +from functools import partial, wraps import keyword import os from pathlib import Path import tokenize import sys from typing import ( - Dict, Generic, Iterable, Iterator, List, Optional, Set, Tuple, Type, TypeVar, Union + Callable, + Dict, + Generic, + Iterable, + Iterator, + List, + Optional, + Set, + Tuple, + Type, + TypeVar, + Union, ) from attr import dataclass, Factory @@ -32,7 +43,9 @@ Depth = int NodeType = int LeafID = int Priority = int +Index = int LN = Union[Leaf, Node] +SplitFunc = Callable[['Line', bool], Iterator['Line']] out = partial(click.secho, bold=True, err=True) err = partial(click.secho, fg='red', err=True) @@ -520,7 +533,7 @@ class Line: depth: int = 0 leaves: List[Leaf] = Factory(list) - comments: Dict[LeafID, Leaf] = Factory(dict) + comments: List[Tuple[Index, Leaf]] = Factory(list) bracket_tracker: BracketTracker = Factory(BracketTracker) inside_brackets: bool = False has_for: bool = False @@ -549,16 +562,31 @@ class Line: self.bracket_tracker.mark(leaf) self.maybe_remove_trailing_comma(leaf) self.maybe_increment_for_loop_variable(leaf) - if self.maybe_adapt_standalone_comment(leaf): - return if not self.append_comment(leaf): self.leaves.append(leaf) + def append_safe(self, leaf: Leaf, preformatted: bool = False) -> None: + """Like :func:`append()` but disallow invalid standalone comment structure. + + Raises ValueError when any `leaf` is appended after a standalone comment + or when a standalone comment is not the first leaf on the line. + """ + if self.bracket_tracker.depth == 0: + if self.is_comment: + raise ValueError("cannot append to standalone comments") + + if self.leaves and leaf.type == STANDALONE_COMMENT: + raise ValueError( + "cannot append standalone comments to a populated line" + ) + + self.append(leaf, preformatted=preformatted) + @property def is_comment(self) -> bool: """Is this line a standalone comment?""" - return bool(self) and self.leaves[0].type == STANDALONE_COMMENT + return len(self.leaves) == 1 and self.leaves[0].type == STANDALONE_COMMENT @property def is_decorator(self) -> bool: @@ -622,6 +650,15 @@ class Line: and self.leaves[0].value == 'yield' ) + @property + def contains_standalone_comments(self) -> bool: + """If so, needs to be split before emitting.""" + for leaf in self.leaves: + if leaf.type == STANDALONE_COMMENT: + return True + + return False + def maybe_remove_trailing_comma(self, closing: Leaf) -> bool: """Remove trailing comma if there is one and it's safe.""" if not ( @@ -632,13 +669,13 @@ class Line: return False if closing.type == token.RBRACE: - self.leaves.pop() + self.remove_trailing_comma() return True if closing.type == token.RSQB: comma = self.leaves[-1] if comma.parent and comma.parent.type == syms.listmaker: - self.leaves.pop() + self.remove_trailing_comma() return True # For parens let's check if it's safe to remove the comma. If the @@ -666,7 +703,7 @@ class Line: break if commas > 1: - self.leaves.pop() + self.remove_trailing_comma() return True return False @@ -694,52 +731,49 @@ class Line: return False - def maybe_adapt_standalone_comment(self, comment: Leaf) -> bool: - """Hack a standalone comment to act as a trailing comment for line splitting. - - If this line has brackets and a standalone `comment`, we need to adapt - it to be able to still reformat the line. - - This is not perfect, the line to which the standalone comment gets - appended will appear "too long" when splitting. - """ - if not ( + def append_comment(self, comment: Leaf) -> bool: + """Add an inline or standalone comment to the line.""" + if ( comment.type == STANDALONE_COMMENT and self.bracket_tracker.any_open_brackets() ): + comment.prefix = '' return False - comment.type = token.COMMENT - comment.prefix = '\n' + ' ' * (self.depth + 1) - return self.append_comment(comment) - - def append_comment(self, comment: Leaf) -> bool: - """Add an inline comment to the line.""" if comment.type != token.COMMENT: return False - try: - after = id(self.last_non_delimiter()) - except LookupError: + after = len(self.leaves) - 1 + if after == -1: comment.type = STANDALONE_COMMENT comment.prefix = '' return False else: - if after in self.comments: - self.comments[after].value += str(comment) - else: - self.comments[after] = comment + self.comments.append((after, comment)) return True - def last_non_delimiter(self) -> Leaf: - """Return the last non-delimiter on the line. Raise LookupError otherwise.""" - for i in range(len(self.leaves)): - last = self.leaves[-i - 1] - if not is_delimiter(last): - return last + def comments_after(self, leaf: Leaf) -> Iterator[Leaf]: + """Generate comments that should appear directly after `leaf`.""" + for _leaf_index, _leaf in enumerate(self.leaves): + if leaf is _leaf: + break + + else: + return - raise LookupError("No non-delimiters found") + for index, comment_after in self.comments: + if _leaf_index == index: + yield comment_after + + def remove_trailing_comma(self) -> None: + """Remove the trailing comma and moves the comments attached to it.""" + comma_index = len(self.leaves) - 1 + for i in range(len(self.comments)): + comment_index, comment = self.comments[i] + if comment_index == comma_index: + self.comments[i] = (comma_index - 1, comment) + self.leaves.pop() def __str__(self) -> str: """Render the line.""" @@ -752,7 +786,7 @@ class Line: res = f'{first.prefix}{indent}{first.value}' for leaf in leaves: res += str(leaf) - for comment in self.comments.values(): + for _, comment in self.comments: res += str(comment) return res + '\n' @@ -809,10 +843,6 @@ class UnformattedLines(Line): """Does nothing and returns False.""" return False - def maybe_adapt_standalone_comment(self, comment: Leaf) -> bool: - """Does nothing and returns False.""" - return False - @dataclass class EmptyLineTracker: @@ -1439,23 +1469,24 @@ def split_line( If `py36` is True, splitting may generate syntax that is only compatible with Python 3.6 and later. """ - if isinstance(line, UnformattedLines): + if isinstance(line, UnformattedLines) or line.is_comment: yield line return line_str = str(line).strip('\n') - if len(line_str) <= line_length and '\n' not in line_str: + if ( + len(line_str) <= line_length + and '\n' not in line_str # multiline strings + and not line.contains_standalone_comments + ): yield line return + split_funcs: List[SplitFunc] if line.is_def: split_funcs = [left_hand_split] elif line.inside_brackets: - split_funcs = [delimiter_split] - if '\n' not in line_str: - # Only attempt RHS if we don't have multiline strings or comments - # on this line. - split_funcs.append(right_hand_split) + split_funcs = [delimiter_split, standalone_comment_split, right_hand_split] else: split_funcs = [right_hand_split] for split_func in split_funcs: @@ -1464,7 +1495,7 @@ def split_line( # split altogether. result: List[Line] = [] try: - for l in split_func(line, py36=py36): + for l in split_func(line, py36): if str(l).strip('\n') == line_str: raise CannotSplit("Split function returned an unchanged result") @@ -1517,8 +1548,7 @@ def left_hand_split(line: Line, py36: bool = False) -> Iterator[Line]: ): for leaf in leaves: result.append(leaf, preformatted=True) - comment_after = line.comments.get(id(leaf)) - if comment_after: + for comment_after in line.comments_after(leaf): result.append(comment_after, preformatted=True) bracket_split_succeeded_or_raise(head, body, tail) for result in (head, body, tail): @@ -1557,8 +1587,7 @@ def right_hand_split(line: Line, py36: bool = False) -> Iterator[Line]: ): for leaf in leaves: result.append(leaf, preformatted=True) - comment_after = line.comments.get(id(leaf)) - if comment_after: + for comment_after in line.comments_after(leaf): result.append(comment_after, preformatted=True) bracket_split_succeeded_or_raise(head, body, tail) for result in (head, body, tail): @@ -1592,10 +1621,25 @@ def bracket_split_succeeded_or_raise(head: Line, body: Line, tail: Line) -> None ) +def dont_increase_indentation(split_func: SplitFunc) -> SplitFunc: + """Normalize prefix of the first leaf in every line returned by `split_func`. + + This is a decorator over relevant split functions. + """ + + @wraps(split_func) + def split_wrapper(line: Line, py36: bool = False) -> Iterator[Line]: + for l in split_func(line, py36): + normalize_prefix(l.leaves[0], inside_brackets=True) + yield l + + return split_wrapper + + +@dont_increase_indentation def delimiter_split(line: Line, py36: bool = False) -> Iterator[Line]: """Split according to delimiters of the highest priority. - This kind of split doesn't increase indentation. If `py36` is True, the split will add trailing commas also in function signatures that contain `*` and `**`. """ @@ -1615,11 +1659,24 @@ def delimiter_split(line: Line, py36: bool = False) -> Iterator[Line]: current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets) lowest_depth = sys.maxsize trailing_comma_safe = True + + def append_to_line(leaf: Leaf) -> Iterator[Line]: + """Append `leaf` to current line or to new line if appending impossible.""" + nonlocal current_line + try: + current_line.append_safe(leaf, preformatted=True) + except ValueError as ve: + yield current_line + + current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets) + current_line.append(leaf) + for leaf in line.leaves: - current_line.append(leaf, preformatted=True) - comment_after = line.comments.get(id(leaf)) - if comment_after: - current_line.append(comment_after, preformatted=True) + yield from append_to_line(leaf) + + for comment_after in line.comments_after(leaf): + yield from append_to_line(comment_after) + lowest_depth = min(lowest_depth, leaf.bracket_depth) if ( leaf.bracket_depth == lowest_depth @@ -1629,7 +1686,6 @@ def delimiter_split(line: Line, py36: bool = False) -> Iterator[Line]: trailing_comma_safe = trailing_comma_safe and py36 leaf_priority = delimiters.get(id(leaf)) if leaf_priority == delimiter_priority: - normalize_prefix(current_line.leaves[0], inside_brackets=True) yield current_line current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets) @@ -1640,7 +1696,40 @@ def delimiter_split(line: Line, py36: bool = False) -> Iterator[Line]: and trailing_comma_safe ): current_line.append(Leaf(token.COMMA, ',')) - normalize_prefix(current_line.leaves[0], inside_brackets=True) + yield current_line + + +@dont_increase_indentation +def standalone_comment_split(line: Line, py36: bool = False) -> Iterator[Line]: + """Split standalone comments from the rest of the line.""" + for leaf in line.leaves: + if leaf.type == STANDALONE_COMMENT: + if leaf.bracket_depth == 0: + break + + else: + raise CannotSplit("Line does not have any standalone comments") + + current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets) + + def append_to_line(leaf: Leaf) -> Iterator[Line]: + """Append `leaf` to current line or to new line if appending impossible.""" + nonlocal current_line + try: + current_line.append_safe(leaf, preformatted=True) + except ValueError as ve: + yield current_line + + current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets) + current_line.append(leaf) + + for leaf in line.leaves: + yield from append_to_line(leaf) + + for comment_after in line.comments_after(leaf): + yield from append_to_line(comment_after) + + if current_line: yield current_line diff --git a/tests/comments3.py b/tests/comments3.py new file mode 100644 index 0000000..b57f8f3 --- /dev/null +++ b/tests/comments3.py @@ -0,0 +1,38 @@ +def func(): + lcomp3 = [ + # This one is actually too long to fit in a single line. + element.split('\n', 1)[0] + # yup + for element in collection.select_elements() + # right + if element is not None + ] + # Capture each of the exceptions in the MultiError along with each of their causes and contexts + if isinstance(exc_value, MultiError): + embedded = [] + for exc in exc_value.exceptions: + if exc not in _seen: + embedded.append( + # This should be left alone (before) + traceback.TracebackException.from_exception( + exc, + limit=limit, + lookup_lines=lookup_lines, + capture_locals=capture_locals, + # copy the set of _seen exceptions so that duplicates + # shared between sub-exceptions are not omitted + _seen=set(_seen), + ) + # This should be left alone (after) + ) + + # everything is fine if the expression isn't nested + traceback.TracebackException.from_exception( + exc, + limit=limit, + lookup_lines=lookup_lines, + capture_locals=capture_locals, + # copy the set of _seen exceptions so that duplicates + # shared between sub-exceptions are not omitted + _seen=set(_seen), + ) diff --git a/tests/test_black.py b/tests/test_black.py index 759bda5..9d7f579 100644 --- a/tests/test_black.py +++ b/tests/test_black.py @@ -150,6 +150,14 @@ class BlackTestCase(unittest.TestCase): black.assert_equivalent(source, actual) black.assert_stable(source, actual, line_length=ll) + @patch("black.dump_to_file", dump_to_stderr) + def test_comments3(self) -> None: + source, expected = read_data('comments3') + actual = fs(source) + self.assertFormatEqual(expected, actual) + black.assert_equivalent(source, actual) + black.assert_stable(source, actual, line_length=ll) + @patch("black.dump_to_file", dump_to_stderr) def test_cantfit(self) -> None: source, expected = read_data('cantfit')