X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/a24e1f795975350f7b1d8898d831916a9f6dbc6a..fc6cea0f0e0f6da99fffbedbfcf3d50cc0e641a4:/src/black/lines.py diff --git a/src/black/lines.py b/src/black/lines.py index f35665c..329dfc4 100644 --- a/src/black/lines.py +++ b/src/black/lines.py @@ -1,6 +1,7 @@ -from dataclasses import dataclass, field import itertools +import math import sys +from dataclasses import dataclass, field from typing import ( Callable, Dict, @@ -10,24 +11,36 @@ from typing import ( Sequence, Tuple, TypeVar, + Union, cast, ) -from blib2to3.pytree import Node, Leaf +from black.brackets import COMMA_PRIORITY, DOT_PRIORITY, BracketTracker +from black.mode import Mode, Preview +from black.nodes import ( + BRACKETS, + CLOSING_BRACKETS, + OPENING_BRACKETS, + STANDALONE_COMMENT, + TEST_DESCENDANTS, + child_towards, + is_import, + is_multiline_string, + is_one_sequence_between, + is_type_comment, + is_with_or_async_with_stmt, + replace_child, + syms, + whitespace, +) from blib2to3.pgen2 import token - -from black.brackets import BracketTracker, DOT_PRIORITY -from black.mode import Mode -from black.nodes import STANDALONE_COMMENT, TEST_DESCENDANTS -from black.nodes import BRACKETS, OPENING_BRACKETS, CLOSING_BRACKETS -from black.nodes import syms, whitespace, replace_child, child_towards -from black.nodes import is_multiline_string, is_import, is_type_comment -from black.nodes import is_one_tuple_between +from blib2to3.pytree import Leaf, Node # types T = TypeVar("T") Index = int LeafID = int +LN = Union[Leaf, Node] @dataclass @@ -44,7 +57,9 @@ class Line: should_split_rhs: bool = False magic_trailing_comma: Optional[Leaf] = None - def append(self, leaf: Leaf, preformatted: bool = False) -> None: + def append( + self, leaf: Leaf, preformatted: bool = False, track_bracket: bool = False + ) -> None: """Add a new `leaf` to the end of the line. Unless `preformatted` is True, the `leaf` will receive a new consistent @@ -66,7 +81,7 @@ class Line: leaf.prefix += whitespace( leaf, complex_subscript=self.is_complex_subscript(leaf) ) - if self.inside_brackets or not preformatted: + if self.inside_brackets or not preformatted or track_bracket: self.bracket_tracker.mark(leaf) if self.mode.magic_trailing_comma: if self.has_magic_trailing_comma(leaf): @@ -108,6 +123,11 @@ class Line: """Is this an import line?""" return bool(self) and is_import(self.leaves[0]) + @property + def is_with_or_async_with_stmt(self) -> bool: + """Is this a with_stmt line?""" + return bool(self) and is_with_or_async_with_stmt(self.leaves[0]) + @property def is_class(self) -> bool: """Is this line a class definition?""" @@ -168,6 +188,13 @@ class Line: and self.leaves[0].value.startswith(('"""', "'''")) ) + @property + def opens_block(self) -> bool: + """Does this line open a new level of indentation.""" + if len(self.leaves) == 0: + return False + return self.leaves[-1].type == token.COLON + def contains_standalone_comments(self, depth_limit: int = sys.maxsize) -> bool: """If so, needs to be split before emitting.""" for leaf in self.leaves: @@ -254,8 +281,10 @@ class Line: """Return True if we have a magic trailing comma, that is when: - there's a trailing comma here - it's not a one-tuple + - it's not a single-element subscript Additionally, if ensure_removable: - it's not from square bracket indexing + (specifically, single-element square bracket indexing) """ if not ( closing.type in CLOSING_BRACKETS @@ -268,15 +297,40 @@ class Line: return True if closing.type == token.RSQB: + if ( + closing.parent + and closing.parent.type == syms.trailer + and closing.opening_bracket + and is_one_sequence_between( + closing.opening_bracket, + closing, + self.leaves, + brackets=(token.LSQB, token.RSQB), + ) + ): + return False + if not ensure_removable: return True + comma = self.leaves[-1] - return bool(comma.parent and comma.parent.type == syms.listmaker) + if comma.parent is None: + return False + return ( + comma.parent.type != syms.subscriptlist + or closing.opening_bracket is None + or not is_one_sequence_between( + closing.opening_bracket, + closing, + self.leaves, + brackets=(token.LSQB, token.RSQB), + ) + ) if self.is_import: return True - if closing.opening_bracket is not None and not is_one_tuple_between( + if closing.opening_bracket is not None and not is_one_sequence_between( closing.opening_bracket, closing, self.leaves ): return True @@ -401,6 +455,39 @@ class Line: return bool(self.leaves or self.comments) +@dataclass +class RHSResult: + """Intermediate split result from a right hand split.""" + + head: Line + body: Line + tail: Line + opening_bracket: Leaf + closing_bracket: Leaf + + +@dataclass +class LinesBlock: + """Class that holds information about a block of formatted lines. + + This is introduced so that the EmptyLineTracker can look behind the standalone + comments and adjust their empty lines for class or def lines. + """ + + mode: Mode + previous_block: Optional["LinesBlock"] + original_line: Line + before: int = 0 + content_lines: List[str] = field(default_factory=list) + after: int = 0 + + def all_lines(self) -> List[str]: + empty_line = str(Line(mode=self.mode)) + return ( + [empty_line * self.before] + self.content_lines + [empty_line * self.after] + ) + + @dataclass class EmptyLineTracker: """Provides a stateful method that returns the number of potential extra @@ -411,33 +498,56 @@ class EmptyLineTracker: are consumed by `maybe_empty_lines()` and included in the computation. """ - is_pyi: bool = False + mode: Mode previous_line: Optional[Line] = None - previous_after: int = 0 + previous_block: Optional[LinesBlock] = None previous_defs: List[int] = field(default_factory=list) + semantic_leading_comment: Optional[LinesBlock] = None - def maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]: + def maybe_empty_lines(self, current_line: Line) -> LinesBlock: """Return the number of extra empty lines before and after the `current_line`. This is for separating `def`, `async def` and `class` with extra empty lines (two on module-level). """ before, after = self._maybe_empty_lines(current_line) + previous_after = self.previous_block.after if self.previous_block else 0 before = ( # Black should not insert empty lines at the beginning # of the file 0 if self.previous_line is None - else before - self.previous_after + else before - previous_after ) - self.previous_after = after + block = LinesBlock( + mode=self.mode, + previous_block=self.previous_block, + original_line=current_line, + before=before, + after=after, + ) + + # Maintain the semantic_leading_comment state. + if current_line.is_comment: + if self.previous_line is None or ( + not self.previous_line.is_decorator + # `or before` means this comment already has an empty line before + and (not self.previous_line.is_comment or before) + and (self.semantic_leading_comment is None or before) + ): + self.semantic_leading_comment = block + # `or before` means this decorator already has an empty line before + elif not current_line.is_decorator or before: + self.semantic_leading_comment = None + self.previous_line = current_line - return before, after + self.previous_block = block + return block def _maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]: max_allowed = 1 if current_line.depth == 0: - max_allowed = 1 if self.is_pyi else 2 + max_allowed = 1 if self.mode.is_pyi else 2 if current_line.leaves: # Consume the first leaf's extra newlines. first_leaf = current_line.leaves[0] @@ -448,7 +558,7 @@ class EmptyLineTracker: before = 0 depth = current_line.depth while self.previous_defs and self.previous_defs[-1] >= depth: - if self.is_pyi: + if self.mode.is_pyi: assert self.previous_line is not None if depth and not current_line.is_def and self.previous_line.is_def: # Empty lines between attributes and methods should be preserved. @@ -498,6 +608,8 @@ class EmptyLineTracker: ): return before, 1 + if self.previous_line and self.previous_line.opens_block: + return 0, 0 return before, 0 def _maybe_empty_lines_for_class_or_def( @@ -510,7 +622,7 @@ class EmptyLineTracker: return 0, 0 if self.previous_line.is_decorator: - if self.is_pyi and current_line.is_stub_class: + if self.mode.is_pyi and current_line.is_stub_class: # Insert an empty line after a decorated stub class return 0, 1 @@ -521,14 +633,25 @@ class EmptyLineTracker: ): return 0, 0 + comment_to_add_newlines: Optional[LinesBlock] = None if ( self.previous_line.is_comment and self.previous_line.depth == current_line.depth and before == 0 ): - return 0, 0 + slc = self.semantic_leading_comment + if ( + slc is not None + and slc.previous_block is not None + and not slc.previous_block.original_line.is_class + and not slc.previous_block.original_line.opens_block + and slc.before <= 1 + ): + comment_to_add_newlines = slc + else: + return 0, 0 - if self.is_pyi: + if self.mode.is_pyi: if current_line.is_class or self.previous_line.is_class: if self.previous_line.depth < current_line.depth: newlines = 0 @@ -556,6 +679,13 @@ class EmptyLineTracker: newlines = 0 else: newlines = 1 if current_line.depth else 2 + if comment_to_add_newlines is not None: + previous_block = comment_to_add_newlines.previous_block + if previous_block is not None: + comment_to_add_newlines.before = ( + max(comment_to_add_newlines.before, newlines) - previous_block.after + ) + newlines = 0 return newlines, 0 @@ -591,18 +721,93 @@ def append_leaves( new_line.append(comment_leaf, preformatted=True) -def is_line_short_enough(line: Line, *, line_length: int, line_str: str = "") -> bool: - """Return True if `line` is no longer than `line_length`. - +def is_line_short_enough( # noqa: C901 + line: Line, *, mode: Mode, line_str: str = "" +) -> bool: + """For non-multiline strings, return True if `line` is no longer than `line_length`. + For multiline strings, looks at the context around `line` to determine + if it should be inlined or split up. Uses the provided `line_str` rendering, if any, otherwise computes a new one. """ if not line_str: line_str = line_to_string(line) - return ( - len(line_str) <= line_length - and "\n" not in line_str # multiline strings - and not line.contains_standalone_comments() - ) + + if Preview.multiline_string_handling not in mode: + return ( + len(line_str) <= mode.line_length + and "\n" not in line_str # multiline strings + and not line.contains_standalone_comments() + ) + + if line.contains_standalone_comments(): + return False + if "\n" not in line_str: + # No multiline strings (MLS) present + return len(line_str) <= mode.line_length + + first, *_, last = line_str.split("\n") + if len(first) > mode.line_length or len(last) > mode.line_length: + return False + + # Traverse the AST to examine the context of the multiline string (MLS), + # tracking aspects such as depth and comma existence, + # to determine whether to split the MLS or keep it together. + # Depth (which is based on the existing bracket_depth concept) + # is needed to determine nesting level of the MLS. + # Includes special case for trailing commas. + commas: List[int] = [] # tracks number of commas per depth level + multiline_string: Optional[Leaf] = None + # store the leaves that contain parts of the MLS + multiline_string_contexts: List[LN] = [] + + max_level_to_update = math.inf # track the depth of the MLS + for i, leaf in enumerate(line.leaves): + if max_level_to_update == math.inf: + had_comma: Optional[int] = None + if leaf.bracket_depth + 1 > len(commas): + commas.append(0) + elif leaf.bracket_depth + 1 < len(commas): + had_comma = commas.pop() + if ( + had_comma is not None + and multiline_string is not None + and multiline_string.bracket_depth == leaf.bracket_depth + 1 + ): + # Have left the level with the MLS, stop tracking commas + max_level_to_update = leaf.bracket_depth + if had_comma > 0: + # MLS was in parens with at least one comma - force split + return False + + if leaf.bracket_depth <= max_level_to_update and leaf.type == token.COMMA: + # Ignore non-nested trailing comma + # directly after MLS/MLS-containing expression + ignore_ctxs: List[Optional[LN]] = [None] + ignore_ctxs += multiline_string_contexts + if not (leaf.prev_sibling in ignore_ctxs and i == len(line.leaves) - 1): + commas[leaf.bracket_depth] += 1 + if max_level_to_update != math.inf: + max_level_to_update = min(max_level_to_update, leaf.bracket_depth) + + if is_multiline_string(leaf): + if len(multiline_string_contexts) > 0: + # >1 multiline string cannot fit on a single line - force split + return False + multiline_string = leaf + ctx: LN = leaf + # fetch the leaf components of the MLS in the AST + while str(ctx) in line_str: + multiline_string_contexts.append(ctx) + if ctx.parent is None: + break + ctx = ctx.parent + + # May not have a triple-quoted multiline string at all, + # in case of a regular string with embedded newlines and line continuations + if len(multiline_string_contexts) == 0: + return True + + return all(val == 0 for val in commas) def can_be_split(line: Line) -> bool: @@ -642,25 +847,42 @@ def can_be_split(line: Line) -> bool: def can_omit_invisible_parens( - line: Line, + rhs: RHSResult, line_length: int, ) -> bool: - """Does `line` have a shape safe to reformat without optional parens around it? + """Does `rhs.body` 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. """ + line = rhs.body 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: + delimiter_count = bt.delimiter_count_with_priority(max_priority) + if delimiter_count > 1: # With more than one delimiter of a kind the optional parentheses read better. return False + if delimiter_count == 1: + if ( + Preview.wrap_multiple_context_managers_in_parens in line.mode + and max_priority == COMMA_PRIORITY + and rhs.head.is_with_or_async_with_stmt + ): + # For two context manager with statements, the optional parentheses read + # better. In this case, `rhs.body` is the context managers part of + # the with statement. `rhs.head` is the `with (` part on the previous + # line. + return False + # Otherwise it may also read better, but we don't do it today and requires + # careful considerations for all possible cases. See + # https://github.com/psf/black/issues/2156. + if max_priority == DOT_PRIORITY: # A single stranded method call doesn't require optional parentheses. return True