Support multiple top-level as-expressions on case statements (#2716)

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

diff --git a/src/black/nodes.py b/src/black/nodes.py
index e0db9a424264ccf807184a28787be8a053fe23c0..75a234740246ec4efed5aedcbfb5eead998abb26 100644 (file)
--- a/src/black/nodes.py
+++ b/src/black/nodes.py
@@ -15,13 +15,19 @@ from typing import (
     Union,
 )
 
-if sys.version_info < (3, 8):
+if sys.version_info >= (3, 8):
+    from typing import Final
+else:
     from typing_extensions import Final
+if sys.version_info >= (3, 10):
+    from typing import TypeGuard
 else:
-    from typing import Final
+    from typing_extensions import TypeGuard
+
+from mypy_extensions import mypyc_attr
 
 # lib2to3 fork
-from blib2to3.pytree import Node, Leaf, type_repr
+from blib2to3.pytree import Node, Leaf, type_repr, NL
 from blib2to3 import pygram
 from blib2to3.pgen2 import token
 
@@ -30,7 +36,7 @@ from black.strings import has_triple_quotes
 
 
 pygram.initialize(CACHE_DIR)
-syms = pygram.python_symbols
+syms: Final = pygram.python_symbols
 
 
 # types
@@ -50,6 +56,8 @@ STATEMENT: Final = {
     syms.with_stmt,
     syms.funcdef,
     syms.classdef,
+    syms.match_stmt,
+    syms.case_block,
 }
 STANDALONE_COMMENT: Final = 153
 token.tok_name[STANDALONE_COMMENT] = "STANDALONE_COMMENT"
@@ -93,6 +101,8 @@ UNPACKING_PARENTS: Final = {
     syms.listmaker,
     syms.testlist_gexp,
     syms.testlist_star_expr,
+    syms.subject_expr,
+    syms.pattern,
 }
 TEST_DESCENDANTS: Final = {
     syms.test,
@@ -128,14 +138,21 @@ ASSIGNMENTS: Final = {
     "//=",
 }
 
-IMPLICIT_TUPLE = {syms.testlist, syms.testlist_star_expr, syms.exprlist}
-BRACKET = {token.LPAR: token.RPAR, token.LSQB: token.RSQB, token.LBRACE: token.RBRACE}
-OPENING_BRACKETS = set(BRACKET.keys())
-CLOSING_BRACKETS = set(BRACKET.values())
-BRACKETS = OPENING_BRACKETS | CLOSING_BRACKETS
-ALWAYS_NO_SPACE = CLOSING_BRACKETS | {token.COMMA, STANDALONE_COMMENT}
+IMPLICIT_TUPLE: Final = {syms.testlist, syms.testlist_star_expr, syms.exprlist}
+BRACKET: Final = {
+    token.LPAR: token.RPAR,
+    token.LSQB: token.RSQB,
+    token.LBRACE: token.RBRACE,
+}
+OPENING_BRACKETS: Final = set(BRACKET.keys())
+CLOSING_BRACKETS: Final = set(BRACKET.values())
+BRACKETS: Final = OPENING_BRACKETS | CLOSING_BRACKETS
+ALWAYS_NO_SPACE: Final = CLOSING_BRACKETS | {token.COMMA, STANDALONE_COMMENT}
+
+RARROW = 55
 
 
+@mypyc_attr(allow_interpreted_subclasses=True)
 class Visitor(Generic[T]):
     """Basic lib2to3 visitor that yields things of type `T` on `visit()`."""
 
@@ -176,9 +193,9 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str:  # noqa: C901
     `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 = "  "
+    NO: Final = ""
+    SPACE: Final = " "
+    DOUBLESPACE: Final = "  "
     t = leaf.type
     p = leaf.parent
     v = leaf.value
@@ -247,8 +264,8 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str:  # noqa: C901
             and prevp.parent
             and prevp.parent.type == syms.shift_expr
             and prevp.prev_sibling
-            and prevp.prev_sibling.type == token.NAME
-            and prevp.prev_sibling.value == "print"  # type: ignore
+            and is_name_token(prevp.prev_sibling)
+            and prevp.prev_sibling.value == "print"
         ):
             # Python 2 print chevron
             return NO
@@ -439,8 +456,8 @@ def prev_siblings_are(node: Optional[LN], tokens: List[Optional[NodeType]]) -> b
 
 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 = None
-    last = None
+    stop_after: Optional[Leaf] = None
+    last: Optional[Leaf] = None
     for leaf in reversed(leaves):
         if stop_after:
             if leaf is stop_after:
@@ -674,7 +691,7 @@ def is_yield(node: LN) -> bool:
     if node.type == syms.yield_expr:
         return True
 
-    if node.type == token.NAME and node.value == "yield":  # type: ignore
+    if is_name_token(node) and node.value == "yield":
         return True
 
     if node.type != syms.atom:
@@ -841,3 +858,19 @@ def ensure_visible(leaf: Leaf) -> None:
         leaf.value = "("
     elif leaf.type == token.RPAR:
         leaf.value = ")"
+
+
+def is_name_token(nl: NL) -> TypeGuard[Leaf]:
+    return nl.type == token.NAME
+
+
+def is_lpar_token(nl: NL) -> TypeGuard[Leaf]:
+    return nl.type == token.LPAR
+
+
+def is_rpar_token(nl: NL) -> TypeGuard[Leaf]:
+    return nl.type == token.RPAR
+
+
+def is_string_token(nl: NL) -> TypeGuard[Leaf]:
+    return nl.type == token.STRING