X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/7c94ed61a55f8ae0c60737cbc6cfee3b5066ce11..a8f68f57fed6cd6bf585b10abd3cc84d37c2fd05:/src/black/nodes.py

diff --git a/src/black/nodes.py b/src/black/nodes.py
index 75a2347..edd201a 100644
--- a/src/black/nodes.py
+++ b/src/black/nodes.py
@@ -3,22 +3,8 @@ blib2to3 Node/Leaf transformation-related utility functions.
 """
 
 import sys
-from typing import (
-    Collection,
-    Generic,
-    Iterator,
-    List,
-    Optional,
-    Set,
-    Tuple,
-    TypeVar,
-    Union,
-)
-
-if sys.version_info >= (3, 8):
-    from typing import Final
-else:
-    from typing_extensions import Final
+from typing import Final, Generic, Iterator, List, Optional, Set, Tuple, TypeVar, Union
+
 if sys.version_info >= (3, 10):
     from typing import TypeGuard
 else:
@@ -26,14 +12,12 @@ else:
 
 from mypy_extensions import mypyc_attr
 
-# lib2to3 fork
-from blib2to3.pytree import Node, Leaf, type_repr, NL
-from blib2to3 import pygram
-from blib2to3.pgen2 import token
-
 from black.cache import CACHE_DIR
+from black.mode import Mode, Preview
 from black.strings import has_triple_quotes
-
+from blib2to3 import pygram
+from blib2to3.pgen2 import token
+from blib2to3.pytree import NL, Leaf, Node, type_repr
 
 pygram.initialize(CACHE_DIR)
 syms: Final = pygram.python_symbols
@@ -121,6 +105,7 @@ TEST_DESCENDANTS: Final = {
     syms.term,
     syms.power,
 }
+TYPED_NAMES: Final = {syms.tname, syms.tname_star}
 ASSIGNMENTS: Final = {
     "=",
     "+=",
@@ -187,15 +172,15 @@ class Visitor(Generic[T]):
                 yield from self.visit(child)
 
 
-def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str:  # noqa: C901
+def whitespace(leaf: Leaf, *, complex_subscript: bool, mode: Mode) -> 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: Final = ""
-    SPACE: Final = " "
-    DOUBLESPACE: Final = "  "
+    NO: Final[str] = ""
+    SPACE: Final[str] = " "
+    DOUBLESPACE: Final[str] = "  "
     t = leaf.type
     p = leaf.parent
     v = leaf.value
@@ -244,6 +229,14 @@ 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
@@ -259,16 +252,6 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str:  # noqa: C901
         ):
             return NO
 
-        elif (
-            prevp.type == token.RIGHTSHIFT
-            and prevp.parent
-            and prevp.parent.type == syms.shift_expr
-            and prevp.prev_sibling
-            and is_name_token(prevp.prev_sibling)
-            and prevp.prev_sibling.value == "print"
-        ):
-            # Python 2 print chevron
-            return NO
         elif prevp.type == token.AT and p.parent and p.parent.type == syms.decorator:
             # no space in decorators
             return NO
@@ -292,7 +275,7 @@ 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:
@@ -303,7 +286,7 @@ 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)
@@ -316,12 +299,7 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str:  # noqa: C901
             return NO
 
         if not prev:
-            if t == token.DOT:
-                prevp = preceding_leaf(p)
-                if not prevp or prevp.type != token.NUMBER:
-                    return NO
-
-            elif t == token.LSQB:
+            if t == token.DOT or t == token.LSQB:
                 return NO
 
         elif prev.type != token.COMMA:
@@ -368,6 +346,11 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str:  # noqa: C901
 
             return NO
 
+        elif Preview.walrus_subscript in mode and (
+            t == token.COLONEQUAL or prev.type == token.COLONEQUAL
+        ):
+            return SPACE
+
         elif not complex_subscript:
             return NO
 
@@ -417,6 +400,10 @@ 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
 
 
@@ -454,27 +441,6 @@ 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:
@@ -538,23 +504,24 @@ def container_of(leaf: Leaf) -> LN:
     return container
 
 
-def first_leaf_column(node: Node) -> Optional[int]:
-    """Returns the column of the first leaf child of a node."""
-    for child in node.children:
-        if isinstance(child, Leaf):
-            return child.column
-    return None
+def first_leaf_of(node: LN) -> Optional[Leaf]:
+    """Returns the first leaf of the node tree."""
+    if isinstance(node, Leaf):
+        return node
+    if node.children:
+        return first_leaf_of(node.children[0])
+    else:
+        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:
@@ -598,9 +565,25 @@ 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_tuple_containing_walrus(node: LN) -> bool:
+    """Return True if `node` holds a tuple that contains a walrus operator."""
+    if node.type != syms.atom:
+        return False
+    gexp = unwrap_singleton_parenthesis(node)
+    if gexp is None or gexp.type != syms.testlist_gexp:
+        return False
+
+    return any(child.type == syms.namedexpr_test for child in gexp.children)
+
+
+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
@@ -737,6 +720,11 @@ def is_multiline_string(leaf: Leaf) -> bool:
 
 def is_stub_suite(node: Node) -> bool:
     """Return True if `node` is a suite with a stub body."""
+
+    # If there is a comment, we want to keep it.
+    if node.prefix.strip():
+        return False
+
     if (
         len(node.children) != 4
         or node.children[0].type != token.NEWLINE
@@ -745,6 +733,9 @@ def is_stub_suite(node: Node) -> bool:
     ):
         return False
 
+    if node.children[3].prefix.strip():
+        return False
+
     return is_stub_body(node.children[2])
 
 
@@ -758,7 +749,8 @@ def is_stub_body(node: LN) -> bool:
 
     child = node.children[0]
     return (
-        child.type == syms.atom
+        not child.prefix.strip()
+        and child.type == syms.atom
         and len(child.children) == 3
         and all(leaf == Leaf(token.DOT, ".") for leaf in child.children)
     )
@@ -808,12 +800,54 @@ def is_import(leaf: Leaf) -> bool:
     )
 
 
-def is_type_comment(leaf: Leaf, suffix: str = "") -> bool:
-    """Return True if the given leaf is a special comment.
-    Only returns true for type comments for now."""
+def is_with_or_async_with_stmt(leaf: Leaf) -> bool:
+    """Return True if the given leaf starts a with or async with statement."""
+    return bool(
+        leaf.type == token.NAME
+        and leaf.value == "with"
+        and leaf.parent
+        and leaf.parent.type == syms.with_stmt
+    ) or bool(
+        leaf.type == token.ASYNC
+        and leaf.next_sibling
+        and leaf.next_sibling.type == syms.with_stmt
+    )
+
+
+def is_async_stmt_or_funcdef(leaf: Leaf) -> bool:
+    """Return True if the given leaf starts an async def/for/with statement.
+
+    Note that `async def` can be either an `async_stmt` or `async_funcdef`,
+    the latter is used when it has decorators.
+    """
+    return bool(
+        leaf.type == token.ASYNC
+        and leaf.parent
+        and leaf.parent.type in {syms.async_stmt, syms.async_funcdef}
+    )
+
+
+def is_type_comment(leaf: Leaf) -> bool:
+    """Return True if the given leaf is a type comment. This function should only
+    be used for general type comments (excluding ignore annotations, which should
+    use `is_type_ignore_comment`). Note that general type comments are no longer
+    used in modern version of Python, this function may be deprecated in the future."""
+    t = leaf.type
+    v = leaf.value
+    return t in {token.COMMENT, STANDALONE_COMMENT} and v.startswith("# type:")
+
+
+def is_type_ignore_comment(leaf: Leaf) -> bool:
+    """Return True if the given leaf is a type comment with ignore annotation."""
     t = leaf.type
     v = leaf.value
-    return t in {token.COMMENT, STANDALONE_COMMENT} and v.startswith("# type:" + suffix)
+    return t in {token.COMMENT, STANDALONE_COMMENT} and is_type_ignore_comment_string(v)
+
+
+def is_type_ignore_comment_string(value: str) -> bool:
+    """Return True if the given string match with type comment with
+    ignore annotation."""
+    return value.startswith("# type: ignore")
 
 
 def wrap_in_parentheses(parent: Node, child: LN, *, visible: bool = True) -> None:
@@ -874,3 +908,19 @@ def is_rpar_token(nl: NL) -> TypeGuard[Leaf]:
 
 def is_string_token(nl: NL) -> TypeGuard[Leaf]:
     return nl.type == token.STRING
+
+
+def is_number_token(nl: NL) -> TypeGuard[Leaf]:
+    return nl.type == token.NUMBER
+
+
+def is_part_of_annotation(leaf: Leaf) -> bool:
+    """Returns whether this leaf is part of type annotations."""
+    ancestor = leaf.parent
+    while ancestor is not None:
+        if ancestor.prev_sibling and ancestor.prev_sibling.type == token.RARROW:
+            return True
+        if ancestor.parent and ancestor.parent.type == syms.tname:
+            return True
+        ancestor = ancestor.parent
+    return False