usse/funda-scraper/venv/lib/python3.10/site-packages/black/brackets.py

343 lines
10 KiB
Python

"""Builds on top of nodes.py to track brackets."""
import sys
from dataclasses import dataclass, field
from typing import Dict, Iterable, List, Optional, Tuple, Union
if sys.version_info < (3, 8):
from typing_extensions import Final
else:
from typing import Final
from black.nodes import (
BRACKET,
CLOSING_BRACKETS,
COMPARATORS,
LOGIC_OPERATORS,
MATH_OPERATORS,
OPENING_BRACKETS,
UNPACKING_PARENTS,
VARARGS_PARENTS,
is_vararg,
syms,
)
from blib2to3.pgen2 import token
from blib2to3.pytree import Leaf, Node
# types
LN = Union[Leaf, Node]
Depth = int
LeafID = int
NodeType = int
Priority = int
COMPREHENSION_PRIORITY: Final = 20
COMMA_PRIORITY: Final = 18
TERNARY_PRIORITY: Final = 16
LOGIC_PRIORITY: Final = 14
STRING_PRIORITY: Final = 12
COMPARATOR_PRIORITY: Final = 10
MATH_PRIORITIES: Final = {
token.VBAR: 9,
token.CIRCUMFLEX: 8,
token.AMPER: 7,
token.LEFTSHIFT: 6,
token.RIGHTSHIFT: 6,
token.PLUS: 5,
token.MINUS: 5,
token.STAR: 4,
token.SLASH: 4,
token.DOUBLESLASH: 4,
token.PERCENT: 4,
token.AT: 4,
token.TILDE: 3,
token.DOUBLESTAR: 2,
}
DOT_PRIORITY: Final = 1
class BracketMatchError(Exception):
"""Raised when an opening bracket is unable to be matched to a closing bracket."""
@dataclass
class BracketTracker:
"""Keeps track of brackets on a line."""
depth: int = 0
bracket_match: Dict[Tuple[Depth, NodeType], Leaf] = field(default_factory=dict)
delimiters: Dict[LeafID, Priority] = field(default_factory=dict)
previous: Optional[Leaf] = None
_for_loop_depths: List[int] = field(default_factory=list)
_lambda_argument_depths: List[int] = field(default_factory=list)
invisible: List[Leaf] = field(default_factory=list)
def mark(self, leaf: Leaf) -> None:
"""Mark `leaf` with bracket-related metadata. Keep track of delimiters.
All leaves receive an int `bracket_depth` field that stores how deep
within brackets a given leaf is. 0 means there are no enclosing brackets
that started on this line.
If a leaf is itself a closing bracket, it receives an `opening_bracket`
field that it forms a pair with. This is a one-directional link to
avoid reference cycles.
If a leaf is a delimiter (a token on which Black can split the line if
needed) and it's on depth 0, its `id()` is stored in the tracker's
`delimiters` field.
"""
if leaf.type == token.COMMENT:
return
self.maybe_decrement_after_for_loop_variable(leaf)
self.maybe_decrement_after_lambda_arguments(leaf)
if leaf.type in CLOSING_BRACKETS:
self.depth -= 1
try:
opening_bracket = self.bracket_match.pop((self.depth, leaf.type))
except KeyError as e:
raise BracketMatchError(
"Unable to match a closing bracket to the following opening"
f" bracket: {leaf}"
) from e
leaf.opening_bracket = opening_bracket
if not leaf.value:
self.invisible.append(leaf)
leaf.bracket_depth = self.depth
if self.depth == 0:
delim = is_split_before_delimiter(leaf, self.previous)
if delim and self.previous is not None:
self.delimiters[id(self.previous)] = delim
else:
delim = is_split_after_delimiter(leaf, self.previous)
if delim:
self.delimiters[id(leaf)] = delim
if leaf.type in OPENING_BRACKETS:
self.bracket_match[self.depth, BRACKET[leaf.type]] = leaf
self.depth += 1
if not leaf.value:
self.invisible.append(leaf)
self.previous = leaf
self.maybe_increment_lambda_arguments(leaf)
self.maybe_increment_for_loop_variable(leaf)
def any_open_brackets(self) -> bool:
"""Return True if there is an yet unmatched open bracket on the line."""
return bool(self.bracket_match)
def max_delimiter_priority(self, exclude: Iterable[LeafID] = ()) -> Priority:
"""Return the highest priority of a delimiter found on the line.
Values are consistent with what `is_split_*_delimiter()` return.
Raises ValueError on no delimiters.
"""
return max(v for k, v in self.delimiters.items() if k not in exclude)
def delimiter_count_with_priority(self, priority: Priority = 0) -> int:
"""Return the number of delimiters with the given `priority`.
If no `priority` is passed, defaults to max priority on the line.
"""
if not self.delimiters:
return 0
priority = priority or self.max_delimiter_priority()
return sum(1 for p in self.delimiters.values() if p == priority)
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, increase the depth of
tokens between `for` and `in`.
"""
if leaf.type == token.NAME and leaf.value == "for":
self.depth += 1
self._for_loop_depths.append(self.depth)
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_depths
and self._for_loop_depths[-1] == self.depth
and leaf.type == token.NAME
and leaf.value == "in"
):
self.depth -= 1
self._for_loop_depths.pop()
return True
return False
def maybe_increment_lambda_arguments(self, leaf: Leaf) -> bool:
"""In a lambda expression, there might be more than one argument.
To avoid splitting on the comma in this situation, increase the depth of
tokens between `lambda` and `:`.
"""
if leaf.type == token.NAME and leaf.value == "lambda":
self.depth += 1
self._lambda_argument_depths.append(self.depth)
return True
return False
def maybe_decrement_after_lambda_arguments(self, leaf: Leaf) -> bool:
"""See `maybe_increment_lambda_arguments` above for explanation."""
if (
self._lambda_argument_depths
and self._lambda_argument_depths[-1] == self.depth
and leaf.type == token.COLON
):
self.depth -= 1
self._lambda_argument_depths.pop()
return True
return False
def get_open_lsqb(self) -> Optional[Leaf]:
"""Return the most recent opening square bracket (if any)."""
return self.bracket_match.get((self.depth - 1, token.RSQB))
def is_split_after_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> Priority:
"""Return the priority of the `leaf` delimiter, given a line break after it.
The delimiter priorities returned here are from those delimiters that would
cause a line break after themselves.
Higher numbers are higher priority.
"""
if leaf.type == token.COMMA:
return COMMA_PRIORITY
return 0
def is_split_before_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> Priority:
"""Return the priority of the `leaf` delimiter, given a line break before it.
The delimiter priorities returned here are from those delimiters that would
cause a line break before themselves.
Higher numbers are higher priority.
"""
if is_vararg(leaf, within=VARARGS_PARENTS | UNPACKING_PARENTS):
# * and ** might also be MATH_OPERATORS but in this case they are not.
# Don't treat them as a delimiter.
return 0
if (
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 in CLOSING_BRACKETS)
):
return DOT_PRIORITY
if (
leaf.type in MATH_OPERATORS
and leaf.parent
and leaf.parent.type not in {syms.factor, syms.star_expr}
):
return MATH_PRIORITIES[leaf.type]
if leaf.type in COMPARATORS:
return COMPARATOR_PRIORITY
if (
leaf.type == token.STRING
and previous is not None
and previous.type == token.STRING
):
return STRING_PRIORITY
if leaf.type not in {token.NAME, token.ASYNC}:
return 0
if (
leaf.value == "for"
and leaf.parent
and leaf.parent.type in {syms.comp_for, syms.old_comp_for}
or leaf.type == token.ASYNC
):
if (
not isinstance(leaf.prev_sibling, Leaf)
or leaf.prev_sibling.value != "async"
):
return COMPREHENSION_PRIORITY
if (
leaf.value == "if"
and leaf.parent
and leaf.parent.type in {syms.comp_if, syms.old_comp_if}
):
return COMPREHENSION_PRIORITY
if leaf.value in {"if", "else"} and leaf.parent and leaf.parent.type == syms.test:
return TERNARY_PRIORITY
if leaf.value == "is":
return COMPARATOR_PRIORITY
if (
leaf.value == "in"
and leaf.parent
and leaf.parent.type in {syms.comp_op, syms.comparison}
and not (
previous is not None
and previous.type == token.NAME
and previous.value == "not"
)
):
return COMPARATOR_PRIORITY
if (
leaf.value == "not"
and leaf.parent
and leaf.parent.type == syms.comp_op
and not (
previous is not None
and previous.type == token.NAME
and previous.value == "is"
)
):
return COMPARATOR_PRIORITY
if leaf.value in LOGIC_OPERATORS and leaf.parent:
return LOGIC_PRIORITY
return 0
def max_delimiter_priority_in_atom(node: LN) -> Priority:
"""Return maximum delimiter priority inside `node`.
This is specific to atoms with contents contained in a pair of parentheses.
If `node` isn't an atom or there are no enclosing parentheses, returns 0.
"""
if node.type != syms.atom:
return 0
first = node.children[0]
last = node.children[-1]
if not (first.type == token.LPAR and last.type == token.RPAR):
return 0
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