]> git.madduck.net Git - etc/vim.git/blobdiff - black.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:

Update README (change log; acks += skapil; acks += tiran)
[etc/vim.git] / black.py
index 95489f3c0c990a650c8efdc4aacb43159d7f8553..46754566fd4aaac239b93c0250fd9c12da2c9d39 100644 (file)
--- a/black.py
+++ b/black.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 import asyncio
 import pickle
 from asyncio.base_events import BaseEventLoop
@@ -43,8 +41,9 @@ from blib2to3 import pygram, pytree
 from blib2to3.pgen2 import driver, token
 from blib2to3.pgen2.parse import ParseError
 
-__version__ = "18.4a2"
+__version__ = "18.4a4"
 DEFAULT_LINE_LENGTH = 88
+
 # types
 syms = pygram.python_symbols
 FileContent = str
@@ -88,11 +87,11 @@ class FormatError(Exception):
         self.consumed = consumed
 
     def trim_prefix(self, leaf: Leaf) -> None:
-        leaf.prefix = leaf.prefix[self.consumed:]
+        leaf.prefix = leaf.prefix[self.consumed :]
 
     def leaf_from_consumed(self, leaf: Leaf) -> Leaf:
         """Returns a new Leaf from the consumed part of the prefix."""
-        unformatted_prefix = leaf.prefix[:self.consumed]
+        unformatted_prefix = leaf.prefix[: self.consumed]
         return Leaf(token.NEWLINE, unformatted_prefix)
 
 
@@ -193,6 +192,7 @@ def main(
         write_back = WriteBack.YES
     report = Report(check=check, quiet=quiet)
     if len(sources) == 0:
+        out("No paths given. Nothing to do 😴")
         ctx.exit(0)
         return
 
@@ -244,7 +244,7 @@ def reformat_one(
                 )
             ):
                 changed = Changed.YES
-            if write_back != WriteBack.DIFF and changed is not Changed.NO:
+            if write_back == WriteBack.YES and changed is not Changed.NO:
                 write_cache(cache, [src], line_length)
         report.done(src, changed)
     except Exception as exc:
@@ -311,7 +311,7 @@ async def schedule_formatting(
 
     if cancelled:
         await asyncio.gather(*cancelled, loop=loop, return_exceptions=True)
-    if write_back != WriteBack.DIFF and formatted:
+    if write_back == WriteBack.YES and formatted:
         write_cache(cache, formatted, line_length)
 
 
@@ -581,6 +581,23 @@ UNPACKING_PARENTS = {
     syms.listmaker,
     syms.testlist_gexp,
 }
+TEST_DESCENDANTS = {
+    syms.test,
+    syms.lambdef,
+    syms.or_test,
+    syms.and_test,
+    syms.not_test,
+    syms.comparison,
+    syms.star_expr,
+    syms.expr,
+    syms.xor_expr,
+    syms.and_expr,
+    syms.shift_expr,
+    syms.arith_expr,
+    syms.trailer,
+    syms.term,
+    syms.power,
+}
 COMPREHENSION_PRIORITY = 20
 COMMA_PRIORITY = 10
 TERNARY_PRIORITY = 7
@@ -697,6 +714,10 @@ class BracketTracker:
 
         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))
+
 
 @dataclass
 class Line:
@@ -722,14 +743,17 @@ class Line:
         if not has_value:
             return
 
+        if token.COLON == leaf.type and self.is_class_paren_empty:
+            del self.leaves[-2:]
         if self.leaves and not preformatted:
             # Note: at this point leaf.prefix should be empty except for
             # imports, for which we only preserve newlines.
-            leaf.prefix += whitespace(leaf)
+            leaf.prefix += whitespace(
+                leaf, complex_subscript=self.is_complex_subscript(leaf)
+            )
         if self.inside_brackets or not preformatted:
             self.bracket_tracker.mark(leaf)
             self.maybe_remove_trailing_comma(leaf)
-
         if not self.append_comment(leaf):
             self.leaves.append(leaf)
 
@@ -817,6 +841,22 @@ class Line:
             and self.leaves[0].value == "yield"
         )
 
+    @property
+    def is_class_paren_empty(self) -> bool:
+        """Is this a class with no base classes but using parentheses?
+
+        Those are unnecessary and should be removed.
+        """
+        return (
+            bool(self)
+            and len(self.leaves) == 4
+            and self.is_class
+            and self.leaves[2].type == token.LPAR
+            and self.leaves[2].value == "("
+            and self.leaves[3].type == token.RPAR
+            and self.leaves[3].value == ")"
+        )
+
     def contains_standalone_comments(self, depth_limit: int = sys.maxsize) -> bool:
         """If so, needs to be split before emitting."""
         for leaf in self.leaves:
@@ -858,7 +898,7 @@ class Line:
         else:
             return False
 
-        for leaf in self.leaves[_opening_index + 1:]:
+        for leaf in self.leaves[_opening_index + 1 :]:
             if leaf is closing:
                 break
 
@@ -919,6 +959,24 @@ class Line:
                 self.comments[i] = (comma_index - 1, comment)
         self.leaves.pop()
 
+    def is_complex_subscript(self, leaf: Leaf) -> bool:
+        """Return True iff `leaf` is part of a slice with non-trivial exprs."""
+        open_lsqb = (
+            leaf if leaf.type == token.LSQB else self.bracket_tracker.get_open_lsqb()
+        )
+        if open_lsqb is None:
+            return False
+
+        subscript_start = open_lsqb.next_sibling
+        if (
+            isinstance(subscript_start, Node)
+            and subscript_start.type == syms.subscriptlist
+        ):
+            subscript_start = child_towards(subscript_start, leaf)
+        return subscript_start is not None and any(
+            n.type in TEST_DESCENDANTS for n in subscript_start.pre_order()
+        )
+
     def __str__(self) -> str:
         """Render the line."""
         if not self:
@@ -1302,8 +1360,12 @@ BRACKETS = OPENING_BRACKETS | CLOSING_BRACKETS
 ALWAYS_NO_SPACE = CLOSING_BRACKETS | {token.COMMA, STANDALONE_COMMENT}
 
 
-def whitespace(leaf: Leaf) -> str:  # noqa C901
-    """Return whitespace prefix if needed for the given `leaf`."""
+def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str:  # noqa C901
+    """Return whitespace prefix if needed for the given `leaf`.
+
+    `complex_subscript` signals whether the given leaf is part of a subscription
+    which has non-trivial arguments, like arithmetic expressions or function calls.
+    """
     NO = ""
     SPACE = " "
     DOUBLESPACE = "  "
@@ -1317,7 +1379,10 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
         return DOUBLESPACE
 
     assert p is not None, f"INTERNAL ERROR: hand-made leaf without parent: {leaf!r}"
-    if t == token.COLON and p.type not in {syms.subscript, syms.subscriptlist}:
+    if (
+        t == token.COLON
+        and p.type not in {syms.subscript, syms.subscriptlist, syms.sliceop}
+    ):
         return NO
 
     prev = leaf.prev_sibling
@@ -1327,7 +1392,13 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
             return NO
 
         if t == token.COLON:
-            return SPACE if prevp.type == token.COMMA else NO
+            if prevp.type == token.COLON:
+                return NO
+
+            elif prevp.type != token.COMMA and not complex_subscript:
+                return NO
+
+            return SPACE
 
         if prevp.type == token.EQUAL:
             if prevp.parent:
@@ -1348,7 +1419,7 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
 
         elif prevp.type == token.COLON:
             if prevp.parent and prevp.parent.type in {syms.subscript, syms.sliceop}:
-                return NO
+                return SPACE if complex_subscript else NO
 
         elif (
             prevp.parent
@@ -1454,7 +1525,7 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
         if prev and prev.type == token.LPAR:
             return NO
 
-    elif p.type == syms.subscript:
+    elif p.type in {syms.subscript, syms.sliceop}:
         # indexing
         if not prev:
             assert p.parent is not None, "subscripts are always parented"
@@ -1463,7 +1534,7 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
 
             return NO
 
-        else:
+        elif not complex_subscript:
             return NO
 
     elif p.type == syms.atom:
@@ -1533,6 +1604,14 @@ def preceding_leaf(node: Optional[LN]) -> Optional[Leaf]:
     return None
 
 
+def child_towards(ancestor: Node, descendant: LN) -> Optional[LN]:
+    """Return the child of `ancestor` that contains `descendant`."""
+    node: Optional[LN] = descendant
+    while node and node.parent != ancestor:
+        node = node.parent
+    return node
+
+
 def is_split_after_delimiter(leaf: Leaf, previous: Leaf = None) -> int:
     """Return the priority of the `leaf` delimiter, given a line break after it.
 
@@ -1712,6 +1791,8 @@ def split_line(
     split_funcs: List[SplitFunc]
     if line.is_def:
         split_funcs = [left_hand_split]
+    elif line.is_import:
+        split_funcs = [explode_split]
     elif line.inside_brackets:
         split_funcs = [delimiter_split, standalone_comment_split, right_hand_split]
     else:
@@ -1978,6 +2059,26 @@ def standalone_comment_split(line: Line, py36: bool = False) -> Iterator[Line]:
         yield current_line
 
 
+def explode_split(
+    line: Line, py36: bool = False, omit: Collection[LeafID] = ()
+) -> Iterator[Line]:
+    """Split by rightmost bracket and immediately split contents by a delimiter."""
+    new_lines = list(right_hand_split(line, py36, omit))
+    if len(new_lines) != 3:
+        yield from new_lines
+        return
+
+    yield new_lines[0]
+
+    try:
+        yield from delimiter_split(new_lines[1], py36)
+
+    except CannotSplit:
+        yield new_lines[1]
+
+    yield new_lines[2]
+
+
 def is_import(leaf: Leaf) -> bool:
     """Return True if the given leaf starts an import statement."""
     p = leaf.parent
@@ -2039,7 +2140,7 @@ def normalize_string_quotes(leaf: Leaf) -> None:
     unescaped_new_quote = re.compile(rf"(([^\\]|^)(\\\\)*){new_quote}")
     escaped_new_quote = re.compile(rf"([^\\]|^)\\(\\\\)*{new_quote}")
     escaped_orig_quote = re.compile(rf"([^\\]|^)\\(\\\\)*{orig_quote}")
-    body = leaf.value[first_quote_pos + len(orig_quote):-len(orig_quote)]
+    body = leaf.value[first_quote_pos + len(orig_quote) : -len(orig_quote)]
     if "r" in prefix.casefold():
         if unescaped_new_quote.search(body):
             # There's at least one unescaped new_quote in this raw string