from typing import (
Any,
Callable,
+ Collection,
Dict,
Generic,
Iterable,
`line_length` and `fast` arguments are passed to :func:`format_file_contents`.
"""
src = sys.stdin.read()
+ dst = src
try:
dst = format_file_contents(src, line_length=line_length, fast=fast)
return True
except NothingChanged:
- dst = src
return False
finally:
"""Return the highest priority of a delimiter found on the line.
Values are consistent with what `is_delimiter()` returns.
+ Raises ValueError on no delimiters.
"""
return max(v for k, v in self.delimiters.items() if k not in exclude)
Inline comments are put aside.
"""
- has_value = leaf.value.strip()
+ has_value = leaf.type in BRACKETS or bool(leaf.value.strip())
if not has_value:
return
and self.leaves[0].value == "yield"
)
- @property
- def contains_standalone_comments(self) -> bool:
+ def contains_standalone_comments(self, depth_limit: int = sys.maxsize) -> bool:
"""If so, needs to be split before emitting."""
for leaf in self.leaves:
if leaf.type == STANDALONE_COMMENT:
- return True
+ if leaf.bracket_depth <= depth_limit:
+ return True
return False
# DEDENT has no value. Additionally, in blib2to3 it never holds comments.
yield from self.line(-1)
- def visit_stmt(self, node: Node, keywords: Set[str]) -> Iterator[Line]:
+ def visit_stmt(
+ self, node: Node, keywords: Set[str], parens: Set[str]
+ ) -> Iterator[Line]:
"""Visit a statement.
This implementation is shared for `if`, `while`, `for`, `try`, `except`,
- `def`, `with`, and `class`.
+ `def`, `with`, `class`, and `assert`.
+
+ The relevant Python language `keywords` for a given statement will be
+ NAME leaves within it. This methods puts those on a separate line.
- The relevant Python language `keywords` for a given statement will be NAME
- leaves within it. This methods puts those on a separate line.
+ `parens` holds pairs of nodes where invisible parentheses should be put.
+ Keys hold nodes after which opening parentheses should be put, values
+ hold nodes before which closing parentheses should be put.
"""
+ normalize_invisible_parens(node, parens_after=parens)
for child in node.children:
if child.type == token.NAME and child.value in keywords: # type: ignore
yield from self.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()
def __attrs_post_init__(self) -> None:
"""You are in a twisty little maze of passages."""
v = self.visit_stmt
- self.visit_if_stmt = partial(v, keywords={"if", "else", "elif"})
- self.visit_while_stmt = partial(v, keywords={"while", "else"})
- self.visit_for_stmt = partial(v, keywords={"for", "else"})
- self.visit_try_stmt = partial(v, keywords={"try", "except", "else", "finally"})
- self.visit_except_clause = partial(v, keywords={"except"})
- self.visit_funcdef = partial(v, keywords={"def"})
- self.visit_with_stmt = partial(v, keywords={"with"})
- self.visit_classdef = partial(v, keywords={"class"})
+ Ø: Set[str] = set()
+ self.visit_assert_stmt = partial(v, keywords={"assert"}, parens={"assert", ","})
+ self.visit_if_stmt = partial(v, keywords={"if", "else", "elif"}, parens={"if"})
+ self.visit_while_stmt = partial(v, keywords={"while", "else"}, parens={"while"})
+ self.visit_for_stmt = partial(v, keywords={"for", "else"}, parens={"for", "in"})
+ self.visit_try_stmt = partial(
+ v, keywords={"try", "except", "else", "finally"}, parens=Ø
+ )
+ self.visit_except_clause = partial(v, keywords={"except"}, parens=Ø)
+ self.visit_with_stmt = partial(v, keywords={"with"}, parens=Ø)
+ self.visit_funcdef = partial(v, keywords={"def"}, parens=Ø)
+ self.visit_classdef = partial(v, keywords={"class"}, parens=Ø)
self.visit_async_funcdef = self.visit_async_stmt
self.visit_decorated = self.visit_decorators
+IMPLICIT_TUPLE = {syms.testlist, syms.testlist_star_expr, syms.exprlist}
BRACKET = {token.LPAR: token.RPAR, token.LSQB: token.RSQB, token.LBRACE: token.RBRACE}
OPENING_BRACKETS = set(BRACKET.keys())
CLOSING_BRACKETS = set(BRACKET.values())
return prevp.prefix
elif prevp.type == token.DOUBLESTAR:
- if prevp.parent and prevp.parent.type in {
- syms.arglist,
- syms.argument,
- syms.dictsetmaker,
- syms.parameters,
- syms.typedargslist,
- syms.varargslist,
- }:
+ if (
+ prevp.parent
+ and prevp.parent.type in {
+ syms.arglist,
+ syms.argument,
+ syms.dictsetmaker,
+ syms.parameters,
+ syms.typedargslist,
+ syms.varargslist,
+ }
+ ):
return NO
elif prevp.type == token.COLON:
prevp_parent = prevp.parent
assert prevp_parent is not None
- if prevp.type == token.COLON and prevp_parent.type in {
- syms.subscript, syms.sliceop
- }:
+ if (
+ prevp.type == token.COLON
+ and prevp_parent.type in {syms.subscript, syms.sliceop}
+ ):
return NO
elif prevp.type == token.EQUAL and prevp_parent.type == syms.argument:
if (
len(line_str) <= line_length
and "\n" not in line_str # multiline strings
- and not line.contains_standalone_comments
+ and not line.contains_standalone_comments()
):
yield line
return
if body_leaves:
normalize_prefix(body_leaves[0], inside_brackets=True)
# Build the new lines.
- for result, leaves in (
- (head, head_leaves), (body, body_leaves), (tail, tail_leaves)
- ):
+ for result, leaves in (head, head_leaves), (body, body_leaves), (tail, tail_leaves):
for leaf in leaves:
result.append(leaf, preformatted=True)
for comment_after in line.comments_after(leaf):
yield result
-def right_hand_split(line: Line, py36: bool = False) -> Iterator[Line]:
+def right_hand_split(
+ line: Line, py36: bool = False, omit: Collection[LeafID] = ()
+) -> 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)
head_leaves: List[Leaf] = []
current_leaves = tail_leaves
opening_bracket = None
+ closing_bracket = None
for leaf in reversed(line.leaves):
if current_leaves is body_leaves:
if leaf is opening_bracket:
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:
+ if leaf.type in CLOSING_BRACKETS and id(leaf) not in omit:
opening_bracket = leaf.opening_bracket
+ closing_bracket = leaf
current_leaves = body_leaves
tail_leaves.reverse()
body_leaves.reverse()
# Since body is a new indent level, remove spurious leading whitespace.
if body_leaves:
normalize_prefix(body_leaves[0], inside_brackets=True)
+ elif not head_leaves:
+ # No `head` and no `body` means the split failed. `tail` has all content.
+ raise CannotSplit("No brackets found")
+
# Build the new lines.
- for result, leaves in (
- (head, head_leaves), (body, body_leaves), (tail, tail_leaves)
- ):
+ for result, leaves in (head, head_leaves), (body, body_leaves), (tail, tail_leaves):
for leaf in leaves:
result.append(leaf, preformatted=True)
for comment_after in line.comments_after(leaf):
result.append(comment_after, preformatted=True)
bracket_split_succeeded_or_raise(head, body, tail)
+ assert opening_bracket and closing_bracket
+ if (
+ opening_bracket.type == token.LPAR
+ and not opening_bracket.value
+ and closing_bracket.type == token.RPAR
+ and not closing_bracket.value
+ ):
+ # These parens were optional. If there aren't any delimiters or standalone
+ # comments in the body, they were unnecessary and another split without
+ # them should be attempted.
+ if not (
+ body.bracket_tracker.delimiters or line.contains_standalone_comments(0)
+ ):
+ omit = {id(closing_bracket), *omit}
+ yield from right_hand_split(line, py36=py36, omit=omit)
+ return
+
+ ensure_visible(opening_bracket)
+ ensure_visible(closing_bracket)
for result in (head, body, tail):
if result:
yield result
@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:
+ if not line.contains_standalone_comments(0):
raise CannotSplit("Line does not have any standalone comments")
current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
leaf.value = f"{prefix}{new_quote}{new_body}{new_quote}"
+def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None:
+ """Make existing optional parentheses invisible or create new ones.
+
+ Standardizes on visible parentheses for single-element tuples, and keeps
+ existing visible parentheses for other tuples and generator expressions.
+ """
+ check_lpar = False
+ for child in list(node.children):
+ if check_lpar:
+ if child.type == syms.atom:
+ if not (
+ is_empty_tuple(child)
+ or is_one_tuple(child)
+ or max_delimiter_priority_in_atom(child) >= COMMA_PRIORITY
+ ):
+ first = child.children[0]
+ last = child.children[-1]
+ if first.type == token.LPAR and last.type == token.RPAR:
+ # make parentheses invisible
+ first.value = "" # type: ignore
+ last.value = "" # type: ignore
+ elif is_one_tuple(child):
+ # wrap child in visible parentheses
+ lpar = Leaf(token.LPAR, "(")
+ rpar = Leaf(token.RPAR, ")")
+ index = child.remove() or 0
+ node.insert_child(index, Node(syms.atom, [lpar, child, rpar]))
+ else:
+ # wrap child in invisible parentheses
+ lpar = Leaf(token.LPAR, "")
+ rpar = Leaf(token.RPAR, "")
+ index = child.remove() or 0
+ node.insert_child(index, Node(syms.atom, [lpar, child, rpar]))
+
+ check_lpar = isinstance(child, Leaf) and child.value in parens_after
+
+
+def is_empty_tuple(node: LN) -> bool:
+ """Return True if `node` holds an empty tuple."""
+ return (
+ node.type == syms.atom
+ and len(node.children) == 2
+ and node.children[0].type == token.LPAR
+ and node.children[1].type == token.RPAR
+ )
+
+
+def is_one_tuple(node: LN) -> bool:
+ """Return True if `node` holds a tuple with one element, with or without parens."""
+ if node.type == syms.atom:
+ if len(node.children) != 3:
+ return False
+
+ lpar, gexp, rpar = node.children
+ if not (
+ lpar.type == token.LPAR
+ and gexp.type == syms.testlist_gexp
+ and rpar.type == token.RPAR
+ ):
+ return False
+
+ return len(gexp.children) == 2 and gexp.children[1].type == token.COMMA
+
+ return (
+ node.type in IMPLICIT_TUPLE
+ and len(node.children) == 2
+ and node.children[1].type == token.COMMA
+ )
+
+
+def max_delimiter_priority_in_atom(node: LN) -> int:
+ if node.type != syms.atom:
+ return 0
+
+ first = node.children[0]
+ last = node.children[-1]
+ if first.type == token.LPAR and last.type == token.RPAR:
+ bt = BracketTracker()
+ for c in node.children[1:-1]:
+ if isinstance(c, Leaf):
+ bt.mark(c)
+ else:
+ for leaf in c.leaves():
+ bt.mark(leaf)
+ try:
+ return bt.max_delimiter_priority()
+
+ except ValueError:
+ return 0
+
+
+def ensure_visible(leaf: Leaf) -> None:
+ """Make sure parentheses are visible.
+
+ They could be invisible as part of some statements (see
+ :func:`normalize_invible_parens` and :func:`visit_import_from`).
+ """
+ if leaf.type == token.LPAR:
+ leaf.value = "("
+ elif leaf.type == token.RPAR:
+ leaf.value = ")"
+
+
def is_python36(node: Node) -> bool:
"""Return True if the current file is using Python 3.6+ features.