506 lines
22 KiB
Python
506 lines
22 KiB
Python
# Copyright 2016 Grist Labs, Inc.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import ast
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import numbers
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import sys
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import token
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from ast import Module
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from typing import Callable, List, Union, cast, Optional, Tuple, TYPE_CHECKING
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import six
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from . import util
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from .asttokens import ASTTokens
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from .util import AstConstant
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from .astroid_compat import astroid_node_classes as nc, BaseContainer as AstroidBaseContainer
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if TYPE_CHECKING:
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from .util import AstNode
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# Mapping of matching braces. To find a token here, look up token[:2].
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_matching_pairs_left = {
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(token.OP, '('): (token.OP, ')'),
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(token.OP, '['): (token.OP, ']'),
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(token.OP, '{'): (token.OP, '}'),
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}
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_matching_pairs_right = {
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(token.OP, ')'): (token.OP, '('),
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(token.OP, ']'): (token.OP, '['),
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(token.OP, '}'): (token.OP, '{'),
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}
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class MarkTokens(object):
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"""
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Helper that visits all nodes in the AST tree and assigns .first_token and .last_token attributes
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to each of them. This is the heart of the token-marking logic.
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"""
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def __init__(self, code):
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# type: (ASTTokens) -> None
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self._code = code
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self._methods = util.NodeMethods()
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self._iter_children = None # type: Optional[Callable]
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def visit_tree(self, node):
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# type: (Module) -> None
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self._iter_children = util.iter_children_func(node)
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util.visit_tree(node, self._visit_before_children, self._visit_after_children)
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def _visit_before_children(self, node, parent_token):
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# type: (AstNode, Optional[util.Token]) -> Tuple[Optional[util.Token], Optional[util.Token]]
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col = getattr(node, 'col_offset', None)
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token = self._code.get_token_from_utf8(node.lineno, col) if col is not None else None
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if not token and util.is_module(node):
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# We'll assume that a Module node starts at the start of the source code.
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token = self._code.get_token(1, 0)
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# Use our own token, or our parent's if we don't have one, to pass to child calls as
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# parent_token argument. The second value becomes the token argument of _visit_after_children.
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return (token or parent_token, token)
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def _visit_after_children(self, node, parent_token, token):
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# type: (AstNode, Optional[util.Token], Optional[util.Token]) -> None
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# This processes the node generically first, after all children have been processed.
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# Get the first and last tokens that belong to children. Note how this doesn't assume that we
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# iterate through children in order that corresponds to occurrence in source code. This
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# assumption can fail (e.g. with return annotations).
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first = token
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last = None
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for child in cast(Callable, self._iter_children)(node):
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# astroid slices have especially wrong positions, we don't want them to corrupt their parents.
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if util.is_empty_astroid_slice(child):
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continue
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if not first or child.first_token.index < first.index:
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first = child.first_token
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if not last or child.last_token.index > last.index:
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last = child.last_token
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# If we don't have a first token from _visit_before_children, and there were no children, then
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# use the parent's token as the first token.
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first = first or parent_token
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# If no children, set last token to the first one.
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last = last or first
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# Statements continue to before NEWLINE. This helps cover a few different cases at once.
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if util.is_stmt(node):
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last = self._find_last_in_stmt(cast(util.Token, last))
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# Capture any unmatched brackets.
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first, last = self._expand_to_matching_pairs(cast(util.Token, first), cast(util.Token, last), node)
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# Give a chance to node-specific methods to adjust.
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nfirst, nlast = self._methods.get(self, node.__class__)(node, first, last)
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if (nfirst, nlast) != (first, last):
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# If anything changed, expand again to capture any unmatched brackets.
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nfirst, nlast = self._expand_to_matching_pairs(nfirst, nlast, node)
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node.first_token = nfirst
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node.last_token = nlast
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def _find_last_in_stmt(self, start_token):
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# type: (util.Token) -> util.Token
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t = start_token
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while (not util.match_token(t, token.NEWLINE) and
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not util.match_token(t, token.OP, ';') and
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not token.ISEOF(t.type)):
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t = self._code.next_token(t, include_extra=True)
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return self._code.prev_token(t)
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def _expand_to_matching_pairs(self, first_token, last_token, node):
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# type: (util.Token, util.Token, AstNode) -> Tuple[util.Token, util.Token]
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"""
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Scan tokens in [first_token, last_token] range that are between node's children, and for any
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unmatched brackets, adjust first/last tokens to include the closing pair.
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"""
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# We look for opening parens/braces among non-child tokens (i.e. tokens between our actual
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# child nodes). If we find any closing ones, we match them to the opens.
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to_match_right = [] # type: List[Tuple[int, str]]
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to_match_left = []
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for tok in self._code.token_range(first_token, last_token):
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tok_info = tok[:2]
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if to_match_right and tok_info == to_match_right[-1]:
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to_match_right.pop()
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elif tok_info in _matching_pairs_left:
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to_match_right.append(_matching_pairs_left[tok_info])
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elif tok_info in _matching_pairs_right:
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to_match_left.append(_matching_pairs_right[tok_info])
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# Once done, extend `last_token` to match any unclosed parens/braces.
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for match in reversed(to_match_right):
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last = self._code.next_token(last_token)
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# Allow for trailing commas or colons (allowed in subscripts) before the closing delimiter
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while any(util.match_token(last, token.OP, x) for x in (',', ':')):
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last = self._code.next_token(last)
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# Now check for the actual closing delimiter.
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if util.match_token(last, *match):
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last_token = last
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# And extend `first_token` to match any unclosed opening parens/braces.
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for match in to_match_left:
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first = self._code.prev_token(first_token)
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if util.match_token(first, *match):
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first_token = first
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return (first_token, last_token)
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#----------------------------------------------------------------------
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# Node visitors. Each takes a preliminary first and last tokens, and returns the adjusted pair
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# that will actually be assigned.
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def visit_default(self, node, first_token, last_token):
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# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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# pylint: disable=no-self-use
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# By default, we don't need to adjust the token we computed earlier.
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return (first_token, last_token)
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def handle_comp(self, open_brace, node, first_token, last_token):
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# type: (str, AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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# For list/set/dict comprehensions, we only get the token of the first child, so adjust it to
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# include the opening brace (the closing brace will be matched automatically).
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before = self._code.prev_token(first_token)
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util.expect_token(before, token.OP, open_brace)
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return (before, last_token)
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# Python 3.8 fixed the starting position of list comprehensions:
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# https://bugs.python.org/issue31241
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if sys.version_info < (3, 8):
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def visit_listcomp(self, node, first_token, last_token):
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# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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return self.handle_comp('[', node, first_token, last_token)
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if six.PY2:
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# We shouldn't do this on PY3 because its SetComp/DictComp already have a correct start.
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def visit_setcomp(self, node, first_token, last_token):
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# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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return self.handle_comp('{', node, first_token, last_token)
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def visit_dictcomp(self, node, first_token, last_token):
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# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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return self.handle_comp('{', node, first_token, last_token)
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def visit_comprehension(self,
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node, # type: AstNode
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first_token, # type: util.Token
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last_token, # type: util.Token
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):
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# type: (...) -> Tuple[util.Token, util.Token]
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# The 'comprehension' node starts with 'for' but we only get first child; we search backwards
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# to find the 'for' keyword.
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first = self._code.find_token(first_token, token.NAME, 'for', reverse=True)
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return (first, last_token)
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def visit_if(self, node, first_token, last_token):
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# type: (util.Token, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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while first_token.string not in ('if', 'elif'):
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first_token = self._code.prev_token(first_token)
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return first_token, last_token
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def handle_attr(self, node, first_token, last_token):
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# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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# Attribute node has ".attr" (2 tokens) after the last child.
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dot = self._code.find_token(last_token, token.OP, '.')
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name = self._code.next_token(dot)
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util.expect_token(name, token.NAME)
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return (first_token, name)
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visit_attribute = handle_attr
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visit_assignattr = handle_attr
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visit_delattr = handle_attr
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def handle_def(self, node, first_token, last_token):
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# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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# With astroid, nodes that start with a doc-string can have an empty body, in which case we
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# need to adjust the last token to include the doc string.
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if not node.body and (getattr(node, 'doc_node', None) or getattr(node, 'doc', None)): # type: ignore[union-attr]
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last_token = self._code.find_token(last_token, token.STRING)
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# Include @ from decorator
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if first_token.index > 0:
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prev = self._code.prev_token(first_token)
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if util.match_token(prev, token.OP, '@'):
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first_token = prev
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return (first_token, last_token)
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visit_classdef = handle_def
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visit_functiondef = handle_def
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def handle_following_brackets(self, node, last_token, opening_bracket):
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# type: (AstNode, util.Token, str) -> util.Token
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# This is for calls and subscripts, which have a pair of brackets
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# at the end which may contain no nodes, e.g. foo() or bar[:].
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# We look for the opening bracket and then let the matching pair be found automatically
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# Remember that last_token is at the end of all children,
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# so we are not worried about encountering a bracket that belongs to a child.
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first_child = next(cast(Callable, self._iter_children)(node))
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call_start = self._code.find_token(first_child.last_token, token.OP, opening_bracket)
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if call_start.index > last_token.index:
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last_token = call_start
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return last_token
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def visit_call(self, node, first_token, last_token):
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# type: (util.Token, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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last_token = self.handle_following_brackets(node, last_token, '(')
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# Handling a python bug with decorators with empty parens, e.g.
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# @deco()
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# def ...
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if util.match_token(first_token, token.OP, '@'):
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first_token = self._code.next_token(first_token)
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return (first_token, last_token)
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def visit_matchclass(self, node, first_token, last_token):
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# type: (util.Token, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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last_token = self.handle_following_brackets(node, last_token, '(')
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return (first_token, last_token)
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def visit_subscript(self,
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node, # type: AstNode
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first_token, # type: util.Token
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last_token, # type: util.Token
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):
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# type: (...) -> Tuple[util.Token, util.Token]
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last_token = self.handle_following_brackets(node, last_token, '[')
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return (first_token, last_token)
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def visit_slice(self, node, first_token, last_token):
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# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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# consume `:` tokens to the left and right. In Python 3.9, Slice nodes are
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# given a col_offset, (and end_col_offset), so this will always start inside
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# the slice, even if it is the empty slice. However, in 3.8 and below, this
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# will only expand to the full slice if the slice contains a node with a
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# col_offset. So x[:] will only get the correct tokens in 3.9, but x[1:] and
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# x[:1] will even on earlier versions of Python.
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while True:
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prev = self._code.prev_token(first_token)
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if prev.string != ':':
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break
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first_token = prev
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while True:
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next_ = self._code.next_token(last_token)
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if next_.string != ':':
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break
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last_token = next_
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return (first_token, last_token)
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def handle_bare_tuple(self, node, first_token, last_token):
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# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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# A bare tuple doesn't include parens; if there is a trailing comma, make it part of the tuple.
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maybe_comma = self._code.next_token(last_token)
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if util.match_token(maybe_comma, token.OP, ','):
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last_token = maybe_comma
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return (first_token, last_token)
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if sys.version_info >= (3, 8):
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# In Python3.8 parsed tuples include parentheses when present.
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def handle_tuple_nonempty(self, node, first_token, last_token):
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# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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assert isinstance(node, ast.Tuple) or isinstance(node, AstroidBaseContainer)
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# It's a bare tuple if the first token belongs to the first child. The first child may
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# include extraneous parentheses (which don't create new nodes), so account for those too.
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child = node.elts[0]
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if TYPE_CHECKING:
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child = cast(AstNode, child)
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child_first, child_last = self._gobble_parens(child.first_token, child.last_token, True)
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if first_token == child_first:
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return self.handle_bare_tuple(node, first_token, last_token)
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return (first_token, last_token)
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else:
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# Before python 3.8, parsed tuples do not include parens.
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def handle_tuple_nonempty(self, node, first_token, last_token):
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# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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(first_token, last_token) = self.handle_bare_tuple(node, first_token, last_token)
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return self._gobble_parens(first_token, last_token, False)
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def visit_tuple(self, node, first_token, last_token):
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# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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assert isinstance(node, ast.Tuple) or isinstance(node, AstroidBaseContainer)
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if not node.elts:
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# An empty tuple is just "()", and we need no further info.
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return (first_token, last_token)
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return self.handle_tuple_nonempty(node, first_token, last_token)
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def _gobble_parens(self, first_token, last_token, include_all=False):
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# type: (util.Token, util.Token, bool) -> Tuple[util.Token, util.Token]
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# Expands a range of tokens to include one or all pairs of surrounding parentheses, and
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# returns (first, last) tokens that include these parens.
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while first_token.index > 0:
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prev = self._code.prev_token(first_token)
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next = self._code.next_token(last_token)
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if util.match_token(prev, token.OP, '(') and util.match_token(next, token.OP, ')'):
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first_token, last_token = prev, next
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if include_all:
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continue
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break
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return (first_token, last_token)
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def visit_str(self, node, first_token, last_token):
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# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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return self.handle_str(first_token, last_token)
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def visit_joinedstr(self,
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node, # type: AstNode
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first_token, # type: util.Token
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last_token, # type: util.Token
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):
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# type: (...) -> Tuple[util.Token, util.Token]
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if sys.version_info < (3, 12):
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# Older versions don't tokenize the contents of f-strings
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return self.handle_str(first_token, last_token)
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last = first_token
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while True:
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if util.match_token(last, getattr(token, "FSTRING_START")):
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# Python 3.12+ has tokens for the start (e.g. `f"`) and end (`"`)
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# of the f-string. We can't just look for the next FSTRING_END
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# because f-strings can be nested, e.g. f"{f'{x}'}", so we need
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# to treat this like matching balanced parentheses.
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count = 1
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while count > 0:
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last = self._code.next_token(last)
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# mypy complains about token.FSTRING_START and token.FSTRING_END.
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if util.match_token(last, getattr(token, "FSTRING_START")):
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count += 1
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elif util.match_token(last, getattr(token, "FSTRING_END")):
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count -= 1
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last_token = last
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last = self._code.next_token(last_token)
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elif util.match_token(last, token.STRING):
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# Similar to handle_str, we also need to handle adjacent strings.
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last_token = last
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last = self._code.next_token(last_token)
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else:
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break
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return (first_token, last_token)
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def visit_bytes(self, node, first_token, last_token):
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# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
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return self.handle_str(first_token, last_token)
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def handle_str(self, first_token, last_token):
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# type: (util.Token, util.Token) -> Tuple[util.Token, util.Token]
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# Multiple adjacent STRING tokens form a single string.
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last = self._code.next_token(last_token)
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while util.match_token(last, token.STRING):
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last_token = last
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last = self._code.next_token(last_token)
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return (first_token, last_token)
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def handle_num(self,
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node, # type: AstNode
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value, # type: Union[complex, int, numbers.Number]
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first_token, # type: util.Token
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last_token, # type: util.Token
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):
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# type: (...) -> Tuple[util.Token, util.Token]
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# A constant like '-1' gets turned into two tokens; this will skip the '-'.
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while util.match_token(last_token, token.OP):
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last_token = self._code.next_token(last_token)
|
|
|
|
if isinstance(value, complex):
|
|
# A complex number like -2j cannot be compared directly to 0
|
|
# A complex number like 1-2j is expressed as a binary operation
|
|
# so we don't need to worry about it
|
|
value = value.imag
|
|
|
|
# This makes sure that the - is included
|
|
if value < 0 and first_token.type == token.NUMBER: # type: ignore[operator]
|
|
first_token = self._code.prev_token(first_token)
|
|
return (first_token, last_token)
|
|
|
|
def visit_num(self, node, first_token, last_token):
|
|
# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
|
|
return self.handle_num(node, cast(ast.Num, node).n, first_token, last_token)
|
|
|
|
# In Astroid, the Num and Str nodes are replaced by Const.
|
|
def visit_const(self, node, first_token, last_token):
|
|
# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
|
|
assert isinstance(node, AstConstant) or isinstance(node, nc.Const)
|
|
if isinstance(node.value, numbers.Number):
|
|
return self.handle_num(node, node.value, first_token, last_token)
|
|
elif isinstance(node.value, (six.text_type, six.binary_type)):
|
|
return self.visit_str(node, first_token, last_token)
|
|
return (first_token, last_token)
|
|
|
|
# In Python >= 3.6, there is a similar class 'Constant' for literals
|
|
# In 3.8 it became the type produced by ast.parse
|
|
# https://bugs.python.org/issue32892
|
|
visit_constant = visit_const
|
|
|
|
def visit_keyword(self, node, first_token, last_token):
|
|
# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
|
|
# Until python 3.9 (https://bugs.python.org/issue40141),
|
|
# ast.keyword nodes didn't have line info. Astroid has lineno None.
|
|
assert isinstance(node, ast.keyword) or isinstance(node, nc.Keyword)
|
|
if node.arg is not None and getattr(node, 'lineno', None) is None:
|
|
equals = self._code.find_token(first_token, token.OP, '=', reverse=True)
|
|
name = self._code.prev_token(equals)
|
|
util.expect_token(name, token.NAME, node.arg)
|
|
first_token = name
|
|
return (first_token, last_token)
|
|
|
|
def visit_starred(self, node, first_token, last_token):
|
|
# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
|
|
# Astroid has 'Starred' nodes (for "foo(*bar)" type args), but they need to be adjusted.
|
|
if not util.match_token(first_token, token.OP, '*'):
|
|
star = self._code.prev_token(first_token)
|
|
if util.match_token(star, token.OP, '*'):
|
|
first_token = star
|
|
return (first_token, last_token)
|
|
|
|
def visit_assignname(self, node, first_token, last_token):
|
|
# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
|
|
# Astroid may turn 'except' clause into AssignName, but we need to adjust it.
|
|
if util.match_token(first_token, token.NAME, 'except'):
|
|
colon = self._code.find_token(last_token, token.OP, ':')
|
|
first_token = last_token = self._code.prev_token(colon)
|
|
return (first_token, last_token)
|
|
|
|
if six.PY2:
|
|
# No need for this on Python3, which already handles 'with' nodes correctly.
|
|
def visit_with(self, node, first_token, last_token):
|
|
# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
|
|
first = self._code.find_token(first_token, token.NAME, 'with', reverse=True)
|
|
return (first, last_token)
|
|
|
|
# Async nodes should typically start with the word 'async'
|
|
# but Python < 3.7 doesn't put the col_offset there
|
|
# AsyncFunctionDef is slightly different because it might have
|
|
# decorators before that, which visit_functiondef handles
|
|
def handle_async(self, node, first_token, last_token):
|
|
# type: (AstNode, util.Token, util.Token) -> Tuple[util.Token, util.Token]
|
|
if not first_token.string == 'async':
|
|
first_token = self._code.prev_token(first_token)
|
|
return (first_token, last_token)
|
|
|
|
visit_asyncfor = handle_async
|
|
visit_asyncwith = handle_async
|
|
|
|
def visit_asyncfunctiondef(self,
|
|
node, # type: AstNode
|
|
first_token, # type: util.Token
|
|
last_token, # type: util.Token
|
|
):
|
|
# type: (...) -> Tuple[util.Token, util.Token]
|
|
if util.match_token(first_token, token.NAME, 'def'):
|
|
# Include the 'async' token
|
|
first_token = self._code.prev_token(first_token)
|
|
return self.visit_functiondef(node, first_token, last_token)
|