import os
from pathlib import Path
import tokenize
+import sys
from typing import (
Dict, Generic, Iterable, Iterator, List, Optional, Set, Tuple, TypeVar, Union
)
-from attr import attrib, dataclass, Factory
+from attr import dataclass, Factory
import click
# lib2to3 fork
from blib2to3.pgen2 import driver, token
from blib2to3.pgen2.parse import ParseError
-__version__ = "18.3a1"
+__version__ = "18.3a2"
DEFAULT_LINE_LENGTH = 88
# types
syms = pygram.python_symbols
comments: List[Line] = []
lines = LineGenerator()
elt = EmptyLineTracker()
+ py36 = is_python36(src_node)
empty_line = Line()
after = 0
for current_line in lines.visit(src_node):
for comment in comments:
dst_contents += str(comment)
comments = []
- for line in split_line(current_line, line_length=line_length):
+ for line in split_line(current_line, line_length=line_length, py36=py36):
dst_contents += str(line)
else:
comments.append(current_line)
- for comment in comments:
- dst_contents += str(comment)
+ if comments:
+ if elt.previous_defs:
+ # Separate postscriptum comments from the last module-level def.
+ dst_contents += str(empty_line)
+ dst_contents += str(empty_line)
+ for comment in comments:
+ dst_contents += str(comment)
return dst_contents
@dataclass
class DebugVisitor(Visitor[T]):
- tree_depth: int = attrib(default=0)
+ tree_depth: int = 0
def visit_default(self, node: LN) -> Iterator[T]:
indent = ' ' * (2 * self.tree_depth)
@dataclass
class BracketTracker:
- depth: int = attrib(default=0)
- bracket_match: Dict[Tuple[Depth, NodeType], Leaf] = attrib(default=Factory(dict))
- delimiters: Dict[LeafID, Priority] = attrib(default=Factory(dict))
- previous: Optional[Leaf] = attrib(default=None)
+ depth: int = 0
+ bracket_match: Dict[Tuple[Depth, NodeType], Leaf] = Factory(dict)
+ delimiters: Dict[LeafID, Priority] = Factory(dict)
+ previous: Optional[Leaf] = None
def mark(self, leaf: Leaf) -> None:
if leaf.type == token.COMMENT:
if leaf.type in CLOSING_BRACKETS:
self.depth -= 1
opening_bracket = self.bracket_match.pop((self.depth, leaf.type))
- leaf.opening_bracket = opening_bracket # type: ignore
- leaf.bracket_depth = self.depth # type: ignore
+ leaf.opening_bracket = opening_bracket
+ leaf.bracket_depth = self.depth
if self.depth == 0:
delim = is_delimiter(leaf)
if delim:
if leaf.type == token.STRING and self.previous.type == token.STRING:
self.delimiters[id(self.previous)] = STRING_PRIORITY
elif (
- leaf.type == token.NAME and
- leaf.value == 'for' and
- leaf.parent and
- leaf.parent.type in {syms.comp_for, syms.old_comp_for}
+ leaf.type == token.NAME
+ and leaf.value == 'for'
+ and leaf.parent
+ and leaf.parent.type in {syms.comp_for, syms.old_comp_for}
):
self.delimiters[id(self.previous)] = COMPREHENSION_PRIORITY
elif (
- leaf.type == token.NAME and
- leaf.value == 'if' and
- leaf.parent and
- leaf.parent.type in {syms.comp_if, syms.old_comp_if}
+ leaf.type == token.NAME
+ and leaf.value == 'if'
+ and leaf.parent
+ and leaf.parent.type in {syms.comp_if, syms.old_comp_if}
):
self.delimiters[id(self.previous)] = COMPREHENSION_PRIORITY
+ elif (
+ leaf.type == token.NAME
+ and leaf.value in LOGIC_OPERATORS
+ and leaf.parent
+ ):
+ self.delimiters[id(self.previous)] = LOGIC_PRIORITY
if leaf.type in OPENING_BRACKETS:
self.bracket_match[self.depth, BRACKET[leaf.type]] = leaf
self.depth += 1
@dataclass
class Line:
- depth: int = attrib(default=0)
- leaves: List[Leaf] = attrib(default=Factory(list))
- comments: Dict[LeafID, Leaf] = attrib(default=Factory(dict))
- bracket_tracker: BracketTracker = attrib(default=Factory(BracketTracker))
- inside_brackets: bool = attrib(default=False)
+ depth: int = 0
+ leaves: List[Leaf] = Factory(list)
+ comments: Dict[LeafID, Leaf] = Factory(dict)
+ bracket_tracker: BracketTracker = Factory(BracketTracker)
+ inside_brackets: bool = False
+ has_for: bool = False
+ _for_loop_variable: bool = False
def append(self, leaf: Leaf, preformatted: bool = False) -> None:
has_value = leaf.value.strip()
# imports, for which we only preserve newlines.
leaf.prefix += whitespace(leaf)
if self.inside_brackets or not preformatted:
+ self.maybe_decrement_after_for_loop_variable(leaf)
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
@property
def is_class(self) -> bool:
return (
- bool(self) and
- self.leaves[0].type == token.NAME and
- self.leaves[0].value == 'class'
+ bool(self)
+ and self.leaves[0].type == token.NAME
+ and self.leaves[0].value == 'class'
)
@property
except IndexError:
second_leaf = None
return (
- (first_leaf.type == token.NAME and first_leaf.value == 'def') or
- (
- first_leaf.type == token.NAME and
- first_leaf.value == 'async' and
- second_leaf is not None and
- second_leaf.type == token.NAME and
- second_leaf.value == 'def'
+ (first_leaf.type == token.NAME and first_leaf.value == 'def')
+ or (
+ first_leaf.type == token.NAME
+ and first_leaf.value == 'async'
+ and second_leaf is not None
+ and second_leaf.type == token.NAME
+ and second_leaf.value == 'def'
)
)
@property
def is_flow_control(self) -> bool:
return (
- bool(self) and
- self.leaves[0].type == token.NAME and
- self.leaves[0].value in FLOW_CONTROL
+ bool(self)
+ and self.leaves[0].type == token.NAME
+ and self.leaves[0].value in FLOW_CONTROL
)
@property
def is_yield(self) -> bool:
return (
- bool(self) and
- self.leaves[0].type == token.NAME and
- self.leaves[0].value == 'yield'
+ bool(self)
+ and self.leaves[0].type == token.NAME
+ and self.leaves[0].value == 'yield'
)
def maybe_remove_trailing_comma(self, closing: Leaf) -> bool:
if not (
- self.leaves and
- self.leaves[-1].type == token.COMMA and
- closing.type in CLOSING_BRACKETS
+ self.leaves
+ and self.leaves[-1].type == token.COMMA
+ and closing.type in CLOSING_BRACKETS
):
return False
# For parens let's check if it's safe to remove the comma. If the
# trailing one is the only one, we might mistakenly change a tuple
# into a different type by removing the comma.
- depth = closing.bracket_depth + 1 # type: ignore
+ depth = closing.bracket_depth + 1
commas = 0
- opening = closing.opening_bracket # type: ignore
+ opening = closing.opening_bracket
for _opening_index, leaf in enumerate(self.leaves):
if leaf is opening:
break
if leaf is closing:
break
- bracket_depth = leaf.bracket_depth # type: ignore
+ bracket_depth = leaf.bracket_depth
if bracket_depth == depth and leaf.type == token.COMMA:
commas += 1
+ if leaf.parent and leaf.parent.type == syms.arglist:
+ commas += 1
+ break
+
if commas > 1:
self.leaves.pop()
return True
return False
+ def maybe_increment_for_loop_variable(self, leaf: Leaf) -> bool:
+ """In a for loop, or comprehension, the variables are often unpacks.
+
+ To avoid splitting on the comma in this situation, we will increase
+ the depth of tokens between `for` and `in`.
+ """
+ if leaf.type == token.NAME and leaf.value == 'for':
+ self.has_for = True
+ self.bracket_tracker.depth += 1
+ self._for_loop_variable = True
+ return True
+
+ return False
+
+ def maybe_decrement_after_for_loop_variable(self, leaf: Leaf) -> bool:
+ # See `maybe_increment_for_loop_variable` above for explanation.
+ if self._for_loop_variable and leaf.type == token.NAME and leaf.value == 'in':
+ self.bracket_tracker.depth -= 1
+ self._for_loop_variable = False
+ return True
+
+ return False
+
def maybe_adapt_standalone_comment(self, comment: Leaf) -> bool:
"""Hack a standalone comment to act as a trailing comment for line splitting.
appended will appear "too long" when splitting.
"""
if not (
- comment.type == STANDALONE_COMMENT and
- self.bracket_tracker.any_open_brackets()
+ comment.type == STANDALONE_COMMENT
+ and self.bracket_tracker.any_open_brackets()
):
return False
"""Provides a stateful method that returns the number of potential extra
empty lines needed before and after the currently processed line.
- Note: this tracker works on lines that haven't been split yet.
+ Note: this tracker works on lines that haven't been split yet. It assumes
+ the prefix of the first leaf consists of optional newlines. Those newlines
+ are consumed by `maybe_empty_lines()` and included in the computation.
"""
- previous_line: Optional[Line] = attrib(default=None)
- previous_after: int = attrib(default=0)
- previous_defs: List[int] = attrib(default=Factory(list))
+ previous_line: Optional[Line] = None
+ previous_after: int = 0
+ previous_defs: List[int] = Factory(list)
def maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
"""Returns the number of extra empty lines before and after the `current_line`.
(two on module-level), as well as providing an extra empty line after flow
control keywords to make them more prominent.
"""
+ if current_line.is_comment:
+ # Don't count standalone comments towards previous empty lines.
+ return 0, 0
+
before, after = self._maybe_empty_lines(current_line)
+ before -= self.previous_after
self.previous_after = after
self.previous_line = current_line
return before, after
def _maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
- before = 0
+ if current_line.leaves:
+ # Consume the first leaf's extra newlines.
+ first_leaf = current_line.leaves[0]
+ before = int('\n' in first_leaf.prefix)
+ first_leaf.prefix = ''
+ else:
+ before = 0
depth = current_line.depth
while self.previous_defs and self.previous_defs[-1] >= depth:
self.previous_defs.pop()
- before = (1 if depth else 2) - self.previous_after
+ before = 1 if depth else 2
is_decorator = current_line.is_decorator
if is_decorator or current_line.is_def or current_line.is_class:
if not is_decorator:
newlines = 2
if current_line.depth:
newlines -= 1
- newlines -= self.previous_after
return newlines, 0
if current_line.is_flow_control:
return before, 1
if (
- self.previous_line and
- self.previous_line.is_import and
- not current_line.is_import and
- depth == self.previous_line.depth
+ self.previous_line
+ and self.previous_line.is_import
+ and not current_line.is_import
+ and depth == self.previous_line.depth
):
return (before or 1), 0
if (
- self.previous_line and
- self.previous_line.is_yield and
- (not current_line.is_yield or depth != self.previous_line.depth)
+ self.previous_line
+ and self.previous_line.is_yield
+ and (not current_line.is_yield or depth != self.previous_line.depth)
):
return (before or 1), 0
Note: destroys the tree it's visiting by mutating prefixes of its leaves
in ways that will no longer stringify to valid Python code on the tree.
"""
- current_line: Line = attrib(default=Factory(Line))
- standalone_comments: List[Leaf] = attrib(default=Factory(list))
+ current_line: Line = Factory(Line)
+ standalone_comments: List[Leaf] = Factory(list)
def line(self, indent: int = 0) -> Iterator[Line]:
"""Generate a line.
OPENING_BRACKETS = set(BRACKET.keys())
CLOSING_BRACKETS = set(BRACKET.values())
BRACKETS = OPENING_BRACKETS | CLOSING_BRACKETS
+ALWAYS_NO_SPACE = CLOSING_BRACKETS | {token.COMMA, token.COLON, STANDALONE_COMMENT}
-def whitespace(leaf: Leaf) -> str:
+def whitespace(leaf: Leaf) -> str: # noqa C901
"""Return whitespace prefix if needed for the given `leaf`."""
NO = ''
SPACE = ' '
t = leaf.type
p = leaf.parent
v = leaf.value
- if t == token.COLON:
- return NO
-
- if t == token.COMMA:
- return NO
-
- if t == token.RPAR:
+ if t in ALWAYS_NO_SPACE:
return NO
if t == token.COMMENT:
return DOUBLESPACE
- if t == STANDALONE_COMMENT:
- return NO
-
- if t in CLOSING_BRACKETS:
- return NO
-
assert p is not None, f"INTERNAL ERROR: hand-made leaf without parent: {leaf!r}"
prev = leaf.prev_sibling
if not prev:
if prevp.parent and prevp.parent.type == syms.subscript:
return NO
- elif prevp.parent and prevp.parent.type == syms.factor:
+ elif prevp.parent and prevp.parent.type in {syms.factor, syms.star_expr}:
return NO
elif prev.type in OPENING_BRACKETS:
elif p.type == syms.subscript:
# indexing
- if not prev or prev.type == token.COLON:
+ if not prev:
+ assert p.parent is not None, "subscripts are always parented"
+ if p.parent.type == syms.subscriptlist:
+ return SPACE
+
+ return NO
+
+ elif prev.type == token.COLON:
return NO
elif p.type == syms.atom:
return NO
elif (
- p.type == syms.listmaker or
- p.type == syms.testlist_gexp or
- p.type == syms.subscriptlist
+ p.type == syms.listmaker
+ or p.type == syms.testlist_gexp
+ or p.type == syms.subscriptlist
):
# list interior, including unpacking
if not prev:
if prev.type == token.DOUBLESTAR:
return NO
- elif p.type == syms.factor or p.type == syms.star_expr:
+ elif p.type in {syms.factor, syms.star_expr}:
# unary ops
if not prev:
prevp = preceding_leaf(p)
if leaf.type == token.COMMA:
return COMMA_PRIORITY
- if leaf.type == token.NAME and leaf.value in LOGIC_OPERATORS:
- return LOGIC_PRIORITY
-
if leaf.type in COMPARATORS:
return COMPARATOR_PRIORITY
if (
- leaf.type in MATH_OPERATORS and
- leaf.parent and
- leaf.parent.type not in {syms.factor, syms.star_expr}
+ leaf.type in MATH_OPERATORS
+ and leaf.parent
+ and leaf.parent.type not in {syms.factor, syms.star_expr}
):
return MATH_PRIORITY
if content and (content[0] not in {' ', '!', '#'}):
content = ' ' + content
is_standalone_comment = (
- '\n' in before_comment or '\n' in content or leaf.type == token.DEDENT
+ '\n' in before_comment or '\n' in content or leaf.type == token.ENDMARKER
)
if not is_standalone_comment:
# simple trailing comment
yield Leaf(STANDALONE_COMMENT, line)
-def split_line(line: Line, line_length: int, inner: bool = False) -> Iterator[Line]:
+def split_line(
+ line: Line, line_length: int, inner: bool = False, py36: bool = False
+) -> Iterator[Line]:
"""Splits a `line` into potentially many lines.
They should fit in the allotted `line_length` but might not be able to.
`inner` signifies that there were a pair of brackets somewhere around the
current `line`, possibly transitively. This means we can fallback to splitting
by delimiters if the LHS/RHS don't yield any results.
+
+ If `py36` is True, splitting may generate syntax that is only compatible
+ with Python 3.6 and later.
"""
line_str = str(line).strip('\n')
if len(line_str) <= line_length and '\n' not in line_str:
# split altogether.
result: List[Line] = []
try:
- for l in split_func(line):
+ for l in split_func(line, py36=py36):
if str(l).strip('\n') == line_str:
raise CannotSplit("Split function returned an unchanged result")
- result.extend(split_line(l, line_length=line_length, inner=True))
+ result.extend(
+ split_line(l, line_length=line_length, inner=True, py36=py36)
+ )
except CannotSplit as cs:
continue
yield line
-def left_hand_split(line: Line) -> Iterator[Line]:
+def left_hand_split(line: Line, py36: bool = False) -> Iterator[Line]:
"""Split line into many lines, starting with the first matching bracket pair.
Note: this usually looks weird, only use this for function definitions.
matching_bracket = None
for leaf in line.leaves:
if (
- current_leaves is body_leaves and
- leaf.type in CLOSING_BRACKETS and
- leaf.opening_bracket is matching_bracket # type: ignore
+ current_leaves is body_leaves
+ and leaf.type in CLOSING_BRACKETS
+ and leaf.opening_bracket is matching_bracket
):
- current_leaves = tail_leaves
+ current_leaves = tail_leaves if body_leaves else head_leaves
current_leaves.append(leaf)
if current_leaves is head_leaves:
if leaf.type in OPENING_BRACKETS:
comment_after = line.comments.get(id(leaf))
if comment_after:
result.append(comment_after, preformatted=True)
- # Check if the split succeeded.
- tail_len = len(str(tail))
- if not body:
- if tail_len == 0:
- raise CannotSplit("Splitting brackets produced the same line")
-
- elif tail_len < 3:
- raise CannotSplit(
- f"Splitting brackets on an empty body to save "
- f"{tail_len} characters is not worth it"
- )
-
+ split_succeeded_or_raise(head, body, tail)
for result in (head, body, tail):
if result:
yield result
-def right_hand_split(line: Line) -> Iterator[Line]:
+def right_hand_split(line: Line, py36: bool = False) -> Iterator[Line]:
"""Split line into many lines, starting with the last matching bracket pair."""
head = Line(depth=line.depth)
body = Line(depth=line.depth + 1, inside_brackets=True)
for leaf in reversed(line.leaves):
if current_leaves is body_leaves:
if leaf is opening_bracket:
- current_leaves = head_leaves
+ current_leaves = head_leaves if body_leaves else tail_leaves
current_leaves.append(leaf)
if current_leaves is tail_leaves:
if leaf.type in CLOSING_BRACKETS:
- opening_bracket = leaf.opening_bracket # type: ignore
+ opening_bracket = leaf.opening_bracket
current_leaves = body_leaves
tail_leaves.reverse()
body_leaves.reverse()
comment_after = line.comments.get(id(leaf))
if comment_after:
result.append(comment_after, preformatted=True)
- # Check if the split succeeded.
- tail_len = len(str(tail).strip('\n'))
+ split_succeeded_or_raise(head, body, tail)
+ for result in (head, body, tail):
+ if result:
+ yield result
+
+
+def split_succeeded_or_raise(head: Line, body: Line, tail: Line) -> None:
+ tail_len = len(str(tail).strip())
if not body:
if tail_len == 0:
raise CannotSplit("Splitting brackets produced the same line")
f"{tail_len} characters is not worth it"
)
- for result in (head, body, tail):
- if result:
- yield result
-
-def delimiter_split(line: Line) -> Iterator[Line]:
+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 **.
"""
try:
last_leaf = line.leaves[-1]
raise CannotSplit("No delimiters found")
current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
+ lowest_depth = sys.maxsize
+ trailing_comma_safe = True
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)
+ lowest_depth = min(lowest_depth, leaf.bracket_depth)
+ if (
+ leaf.bracket_depth == lowest_depth
+ and leaf.type == token.STAR
+ or leaf.type == token.DOUBLESTAR
+ ):
+ 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])
current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
if current_line:
if (
- delimiter_priority == COMMA_PRIORITY and
- current_line.leaves[-1].type != token.COMMA
+ delimiter_priority == COMMA_PRIORITY
+ and current_line.leaves[-1].type != token.COMMA
+ and trailing_comma_safe
):
current_line.append(Leaf(token.COMMA, ','))
normalize_prefix(current_line.leaves[0])
t = leaf.type
v = leaf.value
return bool(
- t == token.NAME and
- (
- (v == 'import' and p and p.type == syms.import_name) or
- (v == 'from' and p and p.type == syms.import_from)
+ t == token.NAME
+ and (
+ (v == 'import' and p and p.type == syms.import_name)
+ or (v == 'from' and p and p.type == syms.import_from)
)
)
if is_import(leaf):
spl = leaf.prefix.split('#', 1)
nl_count = spl[0].count('\n')
- if len(spl) > 1:
- # Skip one newline since it was for a standalone comment.
- nl_count -= 1
leaf.prefix = '\n' * nl_count
return
leaf.prefix = ''
+def is_python36(node: Node) -> bool:
+ """Returns True if the current file is using Python 3.6+ features.
+
+ Currently looking for:
+ - f-strings; and
+ - trailing commas after * or ** in function signatures.
+ """
+ for n in node.pre_order():
+ if n.type == token.STRING:
+ value_head = n.value[:2] # type: ignore
+ if value_head in {'f"', 'F"', "f'", "F'", 'rf', 'fr', 'RF', 'FR'}:
+ return True
+
+ elif (
+ n.type == syms.typedargslist
+ and n.children
+ and n.children[-1].type == token.COMMA
+ ):
+ for ch in n.children:
+ if ch.type == token.STAR or ch.type == token.DOUBLESTAR:
+ return True
+
+ return False
+
+
PYTHON_EXTENSIONS = {'.py'}
BLACKLISTED_DIRECTORIES = {
'build', 'buck-out', 'dist', '_build', '.git', '.hg', '.mypy_cache', '.tox', '.venv'
@dataclass
class Report:
"""Provides a reformatting counter."""
- change_count: int = attrib(default=0)
- same_count: int = attrib(default=0)
- failure_count: int = attrib(default=0)
+ change_count: int = 0
+ same_count: int = 0
+ failure_count: int = 0
def done(self, src: Path, changed: bool) -> None:
"""Increment the counter for successful reformatting. Write out a message."""
raise AssertionError(
f"INTERNAL ERROR: Black produced invalid code: {exc}. "
f"Please report a bug on https://github.com/ambv/black/issues. "
- f"This invalid output might be helpful: {log}",
+ f"This invalid output might be helpful: {log}"
) from None
src_ast_str = '\n'.join(_v(src_ast))
f"INTERNAL ERROR: Black produced code that is not equivalent to "
f"the source. "
f"Please report a bug on https://github.com/ambv/black/issues. "
- f"This diff might be helpful: {log}",
+ f"This diff might be helpful: {log}"
) from None
f"INTERNAL ERROR: Black produced different code on the second pass "
f"of the formatter. "
f"Please report a bug on https://github.com/ambv/black/issues. "
- f"This diff might be helpful: {log}",
+ f"This diff might be helpful: {log}"
) from None
projects / etc / vim.git / blobdiff