Wordsmith current_style.md (#3383)

[etc/vim.git] / src / black / linegen.py

diff --git a/src/black/linegen.py b/src/black/linegen.py
index 1f132b7888fe9a07fda7ad738a198d70e0e4e0a4..219495e9a5e12771ce8837ddcae4c60c24018b73 100644 (file)
--- a/src/black/linegen.py
+++ b/src/black/linegen.py
@@ -1,38 +1,73 @@
 """
 Generating lines of code.
 """
 """
 Generating lines of code.
 """

-from functools import partial, wraps

 import sys
 import sys

+from enum import Enum, auto
+from functools import partial, wraps

 from typing import Collection, Iterator, List, Optional, Set, Union, cast
 
 from typing import Collection, Iterator, List, Optional, Set, Union, cast
 

-from black.nodes import WHITESPACE, RARROW, STATEMENT, STANDALONE_COMMENT
-from black.nodes import ASSIGNMENTS, OPENING_BRACKETS, CLOSING_BRACKETS
-from black.nodes import Visitor, syms, is_arith_like, ensure_visible
+from black.brackets import (
+    COMMA_PRIORITY,
+    DOT_PRIORITY,
+    get_leaves_inside_matching_brackets,
+    max_delimiter_priority_in_atom,
+)
+from black.comments import FMT_OFF, generate_comments, list_comments
+from black.lines import (
+    Line,
+    append_leaves,
+    can_be_split,
+    can_omit_invisible_parens,
+    is_line_short_enough,
+    line_to_string,
+)
+from black.mode import Feature, Mode, Preview

 from black.nodes import (
 from black.nodes import (

+    ASSIGNMENTS,
+    CLOSING_BRACKETS,
+    OPENING_BRACKETS,
+    RARROW,
+    STANDALONE_COMMENT,
+    STATEMENT,
+    WHITESPACE,
+    Visitor,
+    ensure_visible,
+    is_arith_like,
+    is_atom_with_invisible_parens,

     is_docstring,
     is_empty_tuple,
     is_docstring,
     is_empty_tuple,

-    is_one_tuple,
+    is_lpar_token,
+    is_multiline_string,
+    is_name_token,

     is_one_sequence_between,
     is_one_sequence_between,

+    is_one_tuple,
+    is_rpar_token,
+    is_stub_body,
+    is_stub_suite,
+    is_vararg,
+    is_walrus_assignment,
+    is_yield,
+    syms,
+    wrap_in_parentheses,

 )
 )

-from black.nodes import is_name_token, is_lpar_token, is_rpar_token
-from black.nodes import is_walrus_assignment, is_yield, is_vararg, is_multiline_string
-from black.nodes import is_stub_suite, is_stub_body, is_atom_with_invisible_parens
-from black.nodes import wrap_in_parentheses
-from black.brackets import max_delimiter_priority_in_atom
-from black.brackets import DOT_PRIORITY, COMMA_PRIORITY
-from black.lines import Line, line_to_string, is_line_short_enough
-from black.lines import can_omit_invisible_parens, can_be_split, append_leaves
-from black.comments import generate_comments, list_comments, FMT_OFF

 from black.numerics import normalize_numeric_literal
 from black.numerics import normalize_numeric_literal

-from black.strings import get_string_prefix, fix_docstring
-from black.strings import normalize_string_prefix, normalize_string_quotes
-from black.trans import Transformer, CannotTransform, StringMerger, StringSplitter
-from black.trans import StringParenWrapper, StringParenStripper, hug_power_op
-from black.mode import Mode, Feature, Preview
-
-from blib2to3.pytree import Node, Leaf
+from black.strings import (
+    fix_docstring,
+    get_string_prefix,
+    normalize_string_prefix,
+    normalize_string_quotes,
+)
+from black.trans import (
+    CannotTransform,
+    StringMerger,
+    StringParenStripper,
+    StringParenWrapper,
+    StringSplitter,
+    Transformer,
+    hug_power_op,
+)

 from blib2to3.pgen2 import token
 from blib2to3.pgen2 import token

-
+from blib2to3.pytree import Leaf, Node

 
 # types
 LeafID = int
 
 # types
 LeafID = int


@@ -220,7 +255,9 @@ class LineGenerator(Visitor[Line]):
         for child in children:
             yield from self.visit(child)
 
         for child in children:
             yield from self.visit(child)
 

-            if child.type == token.ASYNC:
+            if child.type == token.ASYNC or child.type == STANDALONE_COMMENT:
+                # STANDALONE_COMMENT happens when `# fmt: skip` is applied on the async
+                # line.

                 break
 
         internal_stmt = next(children)
                 break
 
         internal_stmt = next(children)


@@ -530,6 +567,12 @@ def transform_line(
         yield line
 
 
         yield line
 
 

+class _BracketSplitComponent(Enum):
+    head = auto()
+    body = auto()
+    tail = auto()
+
+

 def left_hand_split(line: Line, _features: Collection[Feature] = ()) -> Iterator[Line]:
     """Split line into many lines, starting with the first matching bracket pair.
 
 def left_hand_split(line: Line, _features: Collection[Feature] = ()) -> Iterator[Line]:
     """Split line into many lines, starting with the first matching bracket pair.
 


@@ -560,9 +603,15 @@ def left_hand_split(line: Line, _features: Collection[Feature] = ()) -> Iterator
     if not matching_bracket:
         raise CannotSplit("No brackets found")
 
     if not matching_bracket:
         raise CannotSplit("No brackets found")
 

-    head = bracket_split_build_line(head_leaves, line, matching_bracket)
-    body = bracket_split_build_line(body_leaves, line, matching_bracket, is_body=True)
-    tail = bracket_split_build_line(tail_leaves, line, matching_bracket)
+    head = bracket_split_build_line(
+        head_leaves, line, matching_bracket, component=_BracketSplitComponent.head
+    )
+    body = bracket_split_build_line(
+        body_leaves, line, matching_bracket, component=_BracketSplitComponent.body
+    )
+    tail = bracket_split_build_line(
+        tail_leaves, line, matching_bracket, component=_BracketSplitComponent.tail
+    )

     bracket_split_succeeded_or_raise(head, body, tail)
     for result in (head, body, tail):
         if result:
     bracket_split_succeeded_or_raise(head, body, tail)
     for result in (head, body, tail):
         if result:


@@ -608,9 +657,15 @@ def right_hand_split(
     tail_leaves.reverse()
     body_leaves.reverse()
     head_leaves.reverse()
     tail_leaves.reverse()
     body_leaves.reverse()
     head_leaves.reverse()

-    head = bracket_split_build_line(head_leaves, line, opening_bracket)
-    body = bracket_split_build_line(body_leaves, line, opening_bracket, is_body=True)
-    tail = bracket_split_build_line(tail_leaves, line, opening_bracket)
+    head = bracket_split_build_line(
+        head_leaves, line, opening_bracket, component=_BracketSplitComponent.head
+    )
+    body = bracket_split_build_line(
+        body_leaves, line, opening_bracket, component=_BracketSplitComponent.body
+    )
+    tail = bracket_split_build_line(
+        tail_leaves, line, opening_bracket, component=_BracketSplitComponent.tail
+    )

     bracket_split_succeeded_or_raise(head, body, tail)
     if (
         Feature.FORCE_OPTIONAL_PARENTHESES not in features
     bracket_split_succeeded_or_raise(head, body, tail)
     if (
         Feature.FORCE_OPTIONAL_PARENTHESES not in features


@@ -684,15 +739,23 @@ def bracket_split_succeeded_or_raise(head: Line, body: Line, tail: Line) -> None
 
 
 def bracket_split_build_line(
 
 
 def bracket_split_build_line(

-    leaves: List[Leaf], original: Line, opening_bracket: Leaf, *, is_body: bool = False
+    leaves: List[Leaf],
+    original: Line,
+    opening_bracket: Leaf,
+    *,
+    component: _BracketSplitComponent,

 ) -> Line:
     """Return a new line with given `leaves` and respective comments from `original`.
 
 ) -> Line:
     """Return a new line with given `leaves` and respective comments from `original`.
 

-    If `is_body` is True, the result line is one-indented inside brackets and as such
-    has its first leaf's prefix normalized and a trailing comma added when expected.
+    If it's the head component, brackets will be tracked so trailing commas are
+    respected.
+
+    If it's the body component, the result line is one-indented inside brackets and as
+    such has its first leaf's prefix normalized and a trailing comma added when
+    expected.

     """
     result = Line(mode=original.mode, depth=original.depth)
     """
     result = Line(mode=original.mode, depth=original.depth)

-    if is_body:
+    if component is _BracketSplitComponent.body:

         result.inside_brackets = True
         result.depth += 1
         if leaves:
         result.inside_brackets = True
         result.depth += 1
         if leaves:


@@ -730,12 +793,24 @@ def bracket_split_build_line(
                         leaves.insert(i + 1, new_comma)
                     break
 
                         leaves.insert(i + 1, new_comma)
                     break
 

+    leaves_to_track: Set[LeafID] = set()
+    if (
+        Preview.handle_trailing_commas_in_head in original.mode
+        and component is _BracketSplitComponent.head
+    ):
+        leaves_to_track = get_leaves_inside_matching_brackets(leaves)

     # Populate the line
     for leaf in leaves:
     # Populate the line
     for leaf in leaves:

-        result.append(leaf, preformatted=True)
+        result.append(
+            leaf,
+            preformatted=True,
+            track_bracket=id(leaf) in leaves_to_track,
+        )

         for comment_after in original.comments_after(leaf):
             result.append(comment_after, preformatted=True)
         for comment_after in original.comments_after(leaf):
             result.append(comment_after, preformatted=True)

-    if is_body and should_split_line(result, opening_bracket):
+    if component is _BracketSplitComponent.body and should_split_line(
+        result, opening_bracket
+    ):

         result.should_split_rhs = True
     return result
 
         result.should_split_rhs = True
     return result