Implement support for PEP 646 (#3071)

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

diff --git a/src/black/nodes.py b/src/black/nodes.py
index 51d4cb8618d0a6a2c1f8ac1d55318ed2579fb5d9..918038f69ba4491c7e47492af0f0b3c6f80a3600 100644 (file)
--- a/src/black/nodes.py
+++ b/src/black/nodes.py
@@ -4,7 +4,6 @@ blib2to3 Node/Leaf transformation-related utility functions.
 
 import sys
 from typing import (
-    Collection,
     Generic,
     Iterator,
     List,
@@ -121,6 +120,7 @@ TEST_DESCENDANTS: Final = {
     syms.term,
     syms.power,
 }
+TYPED_NAMES: Final = {syms.tname, syms.tname_star}
 ASSIGNMENTS: Final = {
     "=",
     "+=",
@@ -244,6 +244,14 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str:  # noqa: C901
                     # that, too.
                     return prevp.prefix
 
+        elif (
+            prevp.type == token.STAR
+            and parent_type(prevp) == syms.star_expr
+            and parent_type(prevp.parent) == syms.subscriptlist
+        ):
+            # No space between typevar tuples.
+            return NO
+
         elif prevp.type in VARARGS_SPECIALS:
             if is_vararg(prevp, within=VARARGS_PARENTS | UNPACKING_PARENTS):
                 return NO
@@ -282,7 +290,7 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str:  # noqa: C901
             return NO
 
         if t == token.EQUAL:
-            if prev.type != syms.tname:
+            if prev.type not in TYPED_NAMES:
                 return NO
 
         elif prev.type == token.EQUAL:
@@ -293,7 +301,7 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str:  # noqa: C901
         elif prev.type != token.COMMA:
             return NO
 
-    elif p.type == syms.tname:
+    elif p.type in TYPED_NAMES:
         # type names
         if not prev:
             prevp = preceding_leaf(p)
@@ -402,6 +410,10 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str:  # noqa: C901
     elif p.type == syms.sliceop:
         return NO
 
+    elif p.type == syms.except_clause:
+        if t == token.STAR:
+            return NO
+
     return SPACE
 
 
@@ -439,27 +451,6 @@ def prev_siblings_are(node: Optional[LN], tokens: List[Optional[NodeType]]) -> b
     return prev_siblings_are(node.prev_sibling, tokens[:-1])
 
 
-def last_two_except(leaves: List[Leaf], omit: Collection[LeafID]) -> Tuple[Leaf, Leaf]:
-    """Return (penultimate, last) leaves skipping brackets in `omit` and contents."""
-    stop_after: Optional[Leaf] = None
-    last: Optional[Leaf] = None
-    for leaf in reversed(leaves):
-        if stop_after:
-            if leaf is stop_after:
-                stop_after = None
-            continue
-
-        if last:
-            return leaf, last
-
-        if id(leaf) in omit:
-            stop_after = leaf.opening_bracket
-        else:
-            last = leaf
-    else:
-        raise LookupError("Last two leaves were also skipped")
-
-
 def parent_type(node: Optional[LN]) -> Optional[NodeType]:
     """
     Returns:
@@ -531,15 +522,14 @@ def first_leaf_column(node: Node) -> Optional[int]:
     return None
 
 
-def first_child_is_arith(node: Node) -> bool:
-    """Whether first child is an arithmetic or a binary arithmetic expression"""
-    expr_types = {
+def is_arith_like(node: LN) -> bool:
+    """Whether node is an arithmetic or a binary arithmetic expression"""
+    return node.type in {
         syms.arith_expr,
         syms.shift_expr,
         syms.xor_expr,
         syms.and_expr,
     }
-    return bool(node.children and node.children[0].type in expr_types)
 
 
 def is_docstring(leaf: Leaf) -> bool:
@@ -583,9 +573,14 @@ def is_one_tuple(node: LN) -> bool:
     )
 
 
-def is_one_tuple_between(opening: Leaf, closing: Leaf, leaves: List[Leaf]) -> bool:
-    """Return True if content between `opening` and `closing` looks like a one-tuple."""
-    if opening.type != token.LPAR and closing.type != token.RPAR:
+def is_one_sequence_between(
+    opening: Leaf,
+    closing: Leaf,
+    leaves: List[Leaf],
+    brackets: Tuple[int, int] = (token.LPAR, token.RPAR),
+) -> bool:
+    """Return True if content between `opening` and `closing` is a one-sequence."""
+    if (opening.type, closing.type) != brackets:
         return False
 
     depth = closing.bracket_depth + 1