]> git.madduck.net Git - etc/vim.git/blobdiff - src/black/lines.py

madduck's git repository

Every one of the projects in this repository is available at the canonical URL git://git.madduck.net/madduck/pub/<projectpath> — see each project's metadata for the exact URL.

All patches and comments are welcome. Please squash your changes to logical commits before using git-format-patch and git-send-email to patches@git.madduck.net. If you'd read over the Git project's submission guidelines and adhered to them, I'd be especially grateful.

SSH access, as well as push access can be individually arranged.

If you use my repositories frequently, consider adding the following snippet to ~/.gitconfig and using the third clone URL listed for each project:

[url "git://git.madduck.net/madduck/"]
  insteadOf = madduck:

Bump sphinx-copybutton from 0.5.0 to 0.5.1 in /docs (#3390)
[etc/vim.git] / src / black / lines.py
index 1c4e38a96c14bdcbf4d8d74f79121d677987a41e..08281bcf370a1a987fcffa9602d54a7fe3d71593 100644 (file)
@@ -1,9 +1,8 @@
-from dataclasses import dataclass, field
 import itertools
 import sys
+from dataclasses import dataclass, field
 from typing import (
     Callable,
-    Collection,
     Dict,
     Iterator,
     List,
@@ -14,16 +13,25 @@ from typing import (
     cast,
 )
 
-from blib2to3.pytree import Node, Leaf
+from black.brackets import DOT_PRIORITY, BracketTracker
+from black.mode import Mode, Preview
+from black.nodes import (
+    BRACKETS,
+    CLOSING_BRACKETS,
+    OPENING_BRACKETS,
+    STANDALONE_COMMENT,
+    TEST_DESCENDANTS,
+    child_towards,
+    is_import,
+    is_multiline_string,
+    is_one_sequence_between,
+    is_type_comment,
+    replace_child,
+    syms,
+    whitespace,
+)
 from blib2to3.pgen2 import token
-
-from black.brackets import BracketTracker, DOT_PRIORITY
-from black.mode import Mode
-from black.nodes import STANDALONE_COMMENT, TEST_DESCENDANTS
-from black.nodes import BRACKETS, OPENING_BRACKETS, CLOSING_BRACKETS
-from black.nodes import syms, whitespace, replace_child, child_towards
-from black.nodes import is_multiline_string, is_import, is_type_comment, last_two_except
-from black.nodes import is_one_tuple_between
+from blib2to3.pytree import Leaf, Node
 
 # types
 T = TypeVar("T")
@@ -45,7 +53,9 @@ class Line:
     should_split_rhs: bool = False
     magic_trailing_comma: Optional[Leaf] = None
 
-    def append(self, leaf: Leaf, preformatted: bool = False) -> None:
+    def append(
+        self, leaf: Leaf, preformatted: bool = False, track_bracket: bool = False
+    ) -> None:
         """Add a new `leaf` to the end of the line.
 
         Unless `preformatted` is True, the `leaf` will receive a new consistent
@@ -67,7 +77,7 @@ class Line:
             leaf.prefix += whitespace(
                 leaf, complex_subscript=self.is_complex_subscript(leaf)
             )
-        if self.inside_brackets or not preformatted:
+        if self.inside_brackets or not preformatted or track_bracket:
             self.bracket_tracker.mark(leaf)
             if self.mode.magic_trailing_comma:
                 if self.has_magic_trailing_comma(leaf):
@@ -169,6 +179,13 @@ class Line:
             and self.leaves[0].value.startswith(('"""', "'''"))
         )
 
+    @property
+    def opens_block(self) -> bool:
+        """Does this line open a new level of indentation."""
+        if len(self.leaves) == 0:
+            return False
+        return self.leaves[-1].type == token.COLON
+
     def contains_standalone_comments(self, depth_limit: int = sys.maxsize) -> bool:
         """If so, needs to be split before emitting."""
         for leaf in self.leaves:
@@ -255,8 +272,11 @@ class Line:
         """Return True if we have a magic trailing comma, that is when:
         - there's a trailing comma here
         - it's not a one-tuple
+        - it's not a single-element subscript
         Additionally, if ensure_removable:
         - it's not from square bracket indexing
+        (specifically, single-element square bracket indexing with
+        Preview.skip_magic_trailing_comma_in_subscript)
         """
         if not (
             closing.type in CLOSING_BRACKETS
@@ -269,15 +289,43 @@ class Line:
             return True
 
         if closing.type == token.RSQB:
+            if (
+                Preview.one_element_subscript in self.mode
+                and closing.parent
+                and closing.parent.type == syms.trailer
+                and closing.opening_bracket
+                and is_one_sequence_between(
+                    closing.opening_bracket,
+                    closing,
+                    self.leaves,
+                    brackets=(token.LSQB, token.RSQB),
+                )
+            ):
+                return False
+
             if not ensure_removable:
                 return True
+
             comma = self.leaves[-1]
-            return bool(comma.parent and comma.parent.type == syms.listmaker)
+            if comma.parent is None:
+                return False
+            if Preview.skip_magic_trailing_comma_in_subscript in self.mode:
+                return (
+                    comma.parent.type != syms.subscriptlist
+                    or closing.opening_bracket is None
+                    or not is_one_sequence_between(
+                        closing.opening_bracket,
+                        closing,
+                        self.leaves,
+                        brackets=(token.LSQB, token.RSQB),
+                    )
+                )
+            return comma.parent.type == syms.listmaker
 
         if self.is_import:
             return True
 
-        if closing.opening_bracket is not None and not is_one_tuple_between(
+        if closing.opening_bracket is not None and not is_one_sequence_between(
             closing.opening_bracket, closing, self.leaves
         ):
             return True
@@ -402,6 +450,28 @@ class Line:
         return bool(self.leaves or self.comments)
 
 
+@dataclass
+class LinesBlock:
+    """Class that holds information about a block of formatted lines.
+
+    This is introduced so that the EmptyLineTracker can look behind the standalone
+    comments and adjust their empty lines for class or def lines.
+    """
+
+    mode: Mode
+    previous_block: Optional["LinesBlock"]
+    original_line: Line
+    before: int = 0
+    content_lines: List[str] = field(default_factory=list)
+    after: int = 0
+
+    def all_lines(self) -> List[str]:
+        empty_line = str(Line(mode=self.mode))
+        return (
+            [empty_line * self.before] + self.content_lines + [empty_line * self.after]
+        )
+
+
 @dataclass
 class EmptyLineTracker:
     """Provides a stateful method that returns the number of potential extra
@@ -412,33 +482,55 @@ class EmptyLineTracker:
     are consumed by `maybe_empty_lines()` and included in the computation.
     """
 
-    is_pyi: bool = False
+    mode: Mode
     previous_line: Optional[Line] = None
-    previous_after: int = 0
+    previous_block: Optional[LinesBlock] = None
     previous_defs: List[int] = field(default_factory=list)
+    semantic_leading_comment: Optional[LinesBlock] = None
 
-    def maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
+    def maybe_empty_lines(self, current_line: Line) -> LinesBlock:
         """Return the number of extra empty lines before and after the `current_line`.
 
         This is for separating `def`, `async def` and `class` with extra empty
         lines (two on module-level).
         """
         before, after = self._maybe_empty_lines(current_line)
+        previous_after = self.previous_block.after if self.previous_block else 0
         before = (
             # Black should not insert empty lines at the beginning
             # of the file
             0
             if self.previous_line is None
-            else before - self.previous_after
+            else before - previous_after
+        )
+        block = LinesBlock(
+            mode=self.mode,
+            previous_block=self.previous_block,
+            original_line=current_line,
+            before=before,
+            after=after,
         )
-        self.previous_after = after
+
+        # Maintain the semantic_leading_comment state.
+        if current_line.is_comment:
+            if self.previous_line is None or (
+                not self.previous_line.is_decorator
+                # `or before` means this comment already has an empty line before
+                and (not self.previous_line.is_comment or before)
+                and (self.semantic_leading_comment is None or before)
+            ):
+                self.semantic_leading_comment = block
+        elif not current_line.is_decorator:
+            self.semantic_leading_comment = None
+
         self.previous_line = current_line
-        return before, after
+        self.previous_block = block
+        return block
 
     def _maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
         max_allowed = 1
         if current_line.depth == 0:
-            max_allowed = 1 if self.is_pyi else 2
+            max_allowed = 1 if self.mode.is_pyi else 2
         if current_line.leaves:
             # Consume the first leaf's extra newlines.
             first_leaf = current_line.leaves[0]
@@ -449,7 +541,7 @@ class EmptyLineTracker:
             before = 0
         depth = current_line.depth
         while self.previous_defs and self.previous_defs[-1] >= depth:
-            if self.is_pyi:
+            if self.mode.is_pyi:
                 assert self.previous_line is not None
                 if depth and not current_line.is_def and self.previous_line.is_def:
                     # Empty lines between attributes and methods should be preserved.
@@ -499,6 +591,12 @@ class EmptyLineTracker:
         ):
             return before, 1
 
+        if (
+            Preview.remove_block_trailing_newline in current_line.mode
+            and self.previous_line
+            and self.previous_line.opens_block
+        ):
+            return 0, 0
         return before, 0
 
     def _maybe_empty_lines_for_class_or_def(
@@ -511,7 +609,7 @@ class EmptyLineTracker:
             return 0, 0
 
         if self.previous_line.is_decorator:
-            if self.is_pyi and current_line.is_stub_class:
+            if self.mode.is_pyi and current_line.is_stub_class:
                 # Insert an empty line after a decorated stub class
                 return 0, 1
 
@@ -522,14 +620,27 @@ class EmptyLineTracker:
         ):
             return 0, 0
 
+        comment_to_add_newlines: Optional[LinesBlock] = None
         if (
             self.previous_line.is_comment
             and self.previous_line.depth == current_line.depth
             and before == 0
         ):
-            return 0, 0
+            slc = self.semantic_leading_comment
+            if (
+                Preview.empty_lines_before_class_or_def_with_leading_comments
+                in current_line.mode
+                and slc is not None
+                and slc.previous_block is not None
+                and not slc.previous_block.original_line.is_class
+                and not slc.previous_block.original_line.opens_block
+                and slc.before <= 1
+            ):
+                comment_to_add_newlines = slc
+            else:
+                return 0, 0
 
-        if self.is_pyi:
+        if self.mode.is_pyi:
             if current_line.is_class or self.previous_line.is_class:
                 if self.previous_line.depth < current_line.depth:
                     newlines = 0
@@ -557,6 +668,13 @@ class EmptyLineTracker:
                 newlines = 0
         else:
             newlines = 1 if current_line.depth else 2
+        if comment_to_add_newlines is not None:
+            previous_block = comment_to_add_newlines.previous_block
+            if previous_block is not None:
+                comment_to_add_newlines.before = (
+                    max(comment_to_add_newlines.before, newlines) - previous_block.after
+                )
+                newlines = 0
         return newlines, 0
 
 
@@ -645,7 +763,6 @@ def can_be_split(line: Line) -> bool:
 def can_omit_invisible_parens(
     line: Line,
     line_length: int,
-    omit_on_explode: Collection[LeafID] = (),
 ) -> bool:
     """Does `line` have a shape safe to reformat without optional parens around it?
 
@@ -683,12 +800,6 @@ def can_omit_invisible_parens(
 
     penultimate = line.leaves[-2]
     last = line.leaves[-1]
-    if line.magic_trailing_comma:
-        try:
-            penultimate, last = last_two_except(line.leaves, omit=omit_on_explode)
-        except LookupError:
-            # Turns out we'd omit everything.  We cannot skip the optional parentheses.
-            return False
 
     if (
         last.type == token.RPAR
@@ -710,10 +821,6 @@ def can_omit_invisible_parens(
             # unnecessary.
             return True
 
-        if line.magic_trailing_comma and penultimate.type == token.COMMA:
-            # The rightmost non-omitted bracket pair is the one we want to explode on.
-            return True
-
         if _can_omit_closing_paren(line, last=last, line_length=line_length):
             return True