"""
String transformers that can split and merge strings.
"""
+import re
+import sys
from abc import ABC, abstractmethod
from collections import defaultdict
from dataclasses import dataclass
-import re
from typing import (
Any,
Callable,
TypeVar,
Union,
)
-import sys
if sys.version_info < (3, 8):
- from typing_extensions import Literal, Final
+ from typing_extensions import Final, Literal
else:
from typing import Literal, Final
from mypy_extensions import trait
-from black.rusty import Result, Ok, Err
-
-from black.mode import Feature
-from black.nodes import syms, replace_child, parent_type
-from black.nodes import is_empty_par, is_empty_lpar, is_empty_rpar
-from black.nodes import OPENING_BRACKETS, CLOSING_BRACKETS, STANDALONE_COMMENT
-from black.lines import Line, append_leaves
from black.brackets import BracketMatchError
from black.comments import contains_pragma_comment
-from black.strings import has_triple_quotes, get_string_prefix, assert_is_leaf_string
-from black.strings import normalize_string_quotes
-
-from blib2to3.pytree import Leaf, Node
+from black.lines import Line, append_leaves
+from black.mode import Feature
+from black.nodes import (
+ CLOSING_BRACKETS,
+ OPENING_BRACKETS,
+ STANDALONE_COMMENT,
+ is_empty_lpar,
+ is_empty_par,
+ is_empty_rpar,
+ parent_type,
+ replace_child,
+ syms,
+)
+from black.rusty import Err, Ok, Result
+from black.strings import (
+ assert_is_leaf_string,
+ get_string_prefix,
+ has_triple_quotes,
+ normalize_string_quotes,
+)
from blib2to3.pgen2 import token
+from blib2to3.pytree import Leaf, Node
class CannotTransform(Exception):
return False
- leaves: List[Leaf] = []
+ new_line = line.clone()
should_hug = False
for idx, leaf in enumerate(line.leaves):
new_leaf = leaf.clone()
if should_hug:
new_leaf.prefix = ""
- leaves.append(new_leaf)
-
- yield Line(
- mode=line.mode,
- depth=line.depth,
- leaves=leaves,
- comments=line.comments,
- bracket_tracker=line.bracket_tracker,
- inside_brackets=line.inside_brackets,
- should_split_rhs=line.should_split_rhs,
- magic_trailing_comma=line.magic_trailing_comma,
- )
+ # We have to be careful to make a new line properly:
+ # - bracket related metadata must be maintained (handled by Line.append)
+ # - comments need to copied over, updating the leaf IDs they're attached to
+ new_line.append(new_leaf, preformatted=True)
+ for comment_leaf in line.comments_after(leaf):
+ new_line.append(comment_leaf, preformatted=True)
+
+ yield new_line
class StringTransformer(ABC):
next_str_idx += 1
+ # Take a note on the index of the non-STRING leaf.
+ non_string_idx = next_str_idx
+
S_leaf = Leaf(token.STRING, S)
if self.normalize_strings:
S_leaf.value = normalize_string_quotes(S_leaf.value)
string_leaf = Leaf(token.STRING, S_leaf.value.replace(BREAK_MARK, ""))
if atom_node is not None:
- replace_child(atom_node, string_leaf)
+ # If not all children of the atom node are merged (this can happen
+ # when there is a standalone comment in the middle) ...
+ if non_string_idx - string_idx < len(atom_node.children):
+ # We need to replace the old STRING leaves with the new string leaf.
+ first_child_idx = LL[string_idx].remove()
+ for idx in range(string_idx + 1, non_string_idx):
+ LL[idx].remove()
+ if first_child_idx is not None:
+ atom_node.insert_child(first_child_idx, string_leaf)
+ else:
+ # Else replace the atom node with the new string leaf.
+ replace_child(atom_node, string_leaf)
# Build the final line ('new_line') that this method will later return.
new_line = line.clone()
max_string_length = self.line_length - offset
return max_string_length
+ @staticmethod
+ def _prefer_paren_wrap_match(LL: List[Leaf]) -> Optional[int]:
+ """
+ Returns:
+ string_idx such that @LL[string_idx] is equal to our target (i.e.
+ matched) string, if this line matches the "prefer paren wrap" statement
+ requirements listed in the 'Requirements' section of the StringParenWrapper
+ class's docstring.
+ OR
+ None, otherwise.
+ """
+ # The line must start with a string.
+ if LL[0].type != token.STRING:
+ return None
+
+ # If the string is surrounded by commas (or is the first/last child)...
+ prev_sibling = LL[0].prev_sibling
+ next_sibling = LL[0].next_sibling
+ if not prev_sibling and not next_sibling and parent_type(LL[0]) == syms.atom:
+ # If it's an atom string, we need to check the parent atom's siblings.
+ parent = LL[0].parent
+ assert parent is not None # For type checkers.
+ prev_sibling = parent.prev_sibling
+ next_sibling = parent.next_sibling
+ if (not prev_sibling or prev_sibling.type == token.COMMA) and (
+ not next_sibling or next_sibling.type == token.COMMA
+ ):
+ return 0
+
+ return None
+
def iter_fexpr_spans(s: str) -> Iterator[Tuple[int, int]]:
"""
def do_splitter_match(self, line: Line) -> TMatchResult:
LL = line.leaves
+ if self._prefer_paren_wrap_match(LL) is not None:
+ return TErr("Line needs to be wrapped in parens first.")
+
is_valid_index = is_valid_index_factory(LL)
idx = 0
string_op_leaves = self._get_string_operator_leaves(LL)
string_op_leaves_length = (
- sum([len(str(prefix_leaf)) for prefix_leaf in string_op_leaves]) + 1
+ sum(len(str(prefix_leaf)) for prefix_leaf in string_op_leaves) + 1
if string_op_leaves
else 0
)
class StringParenWrapper(BaseStringSplitter, CustomSplitMapMixin):
"""
- StringTransformer that splits non-"atom" strings (i.e. strings that do not
- exist on lines by themselves).
+ StringTransformer that wraps strings in parens and then splits at the LPAR.
Requirements:
All of the requirements listed in BaseStringSplitter's docstring in
OR
* The line is a dictionary key assignment where some valid key is being
assigned the value of some string.
+ OR
+ * The line is an lambda expression and the value is a string.
+ OR
+ * The line starts with an "atom" string that prefers to be wrapped in
+ parens. It's preferred to be wrapped when the string is surrounded by
+ commas (or is the first/last child).
Transformations:
The chosen string is wrapped in parentheses and then split at the LPAR.
changed such that it no longer needs to be given its own line,
StringParenWrapper relies on StringParenStripper to clean up the
parentheses it created.
+
+ For "atom" strings that prefers to be wrapped in parens, it requires
+ StringSplitter to hold the split until the string is wrapped in parens.
"""
def do_splitter_match(self, line: Line) -> TMatchResult:
or self._else_match(LL)
or self._assert_match(LL)
or self._assign_match(LL)
- or self._dict_match(LL)
+ or self._dict_or_lambda_match(LL)
+ or self._prefer_paren_wrap_match(LL)
)
if string_idx is not None:
return None
@staticmethod
- def _dict_match(LL: List[Leaf]) -> Optional[int]:
+ def _dict_or_lambda_match(LL: List[Leaf]) -> Optional[int]:
"""
Returns:
string_idx such that @LL[string_idx] is equal to our target (i.e.
matched) string, if this line matches the dictionary key assignment
- statement requirements listed in the 'Requirements' section of this
- classes' docstring.
+ statement or lambda expression requirements listed in the
+ 'Requirements' section of this classes' docstring.
OR
None, otherwise.
"""
- # If this line is apart of a dictionary key assignment...
- if syms.dictsetmaker in [parent_type(LL[0]), parent_type(LL[0].parent)]:
+ # If this line is a part of a dictionary key assignment or lambda expression...
+ parent_types = [parent_type(LL[0]), parent_type(LL[0].parent)]
+ if syms.dictsetmaker in parent_types or syms.lambdef in parent_types:
is_valid_index = is_valid_index_factory(LL)
for i, leaf in enumerate(LL):
- # We MUST find a colon...
+ # We MUST find a colon, it can either be dict's or lambda's colon...
if leaf.type == token.COLON:
idx = i + 2 if is_empty_par(LL[i + 1]) else i + 1
f" (left_leaves={left_leaves}, right_leaves={right_leaves})"
)
old_rpar_leaf = right_leaves.pop()
+ elif right_leaves and right_leaves[-1].type == token.RPAR:
+ # Special case for lambda expressions as dict's value, e.g.:
+ # my_dict = {
+ # "key": lambda x: f"formatted: {x},
+ # }
+ # After wrapping the dict's value with parentheses, the string is
+ # followed by a RPAR but its opening bracket is lambda's, not
+ # the string's:
+ # "key": (lambda x: f"formatted: {x}),
+ opening_bracket = right_leaves[-1].opening_bracket
+ if opening_bracket is not None and opening_bracket in left_leaves:
+ index = left_leaves.index(opening_bracket)
+ if (
+ index > 0
+ and index < len(left_leaves) - 1
+ and left_leaves[index - 1].type == token.COLON
+ and left_leaves[index + 1].value == "lambda"
+ ):
+ right_leaves.pop()
append_leaves(string_line, line, right_leaves)