--- /dev/null
+"""Builds on top of nodes.py to track brackets."""
+
+from dataclasses import dataclass, field
+import sys
+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 blib2to3.pytree import Leaf, Node
+from blib2to3.pgen2 import token
+
+from black.nodes import syms, is_vararg, VARARGS_PARENTS, UNPACKING_PARENTS
+from black.nodes import BRACKET, OPENING_BRACKETS, CLOSING_BRACKETS
+from black.nodes import MATH_OPERATORS, COMPARATORS, LOGIC_OPERATORS
+
+# 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(KeyError):
+ """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
projects / etc / vim.git / blobdiff