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1# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
2# For details: https://github.com/pylint-dev/astroid/blob/main/LICENSE
3# Copyright (c) https://github.com/pylint-dev/astroid/blob/main/CONTRIBUTORS.txt
5"""This module contains mixin classes for scoped nodes."""
7from __future__ import annotations
9import sys
10from typing import TYPE_CHECKING, overload
12from astroid.exceptions import ParentMissingError
13from astroid.filter_statements import _filter_stmts
14from astroid.nodes import _base_nodes, scoped_nodes
15from astroid.nodes.scoped_nodes.utils import builtin_lookup
16from astroid.typing import InferenceResult, SuccessfulInferenceResult
18if sys.version_info >= (3, 11):
19 from typing import Self
20else:
21 from typing_extensions import Self
22if TYPE_CHECKING:
23 from astroid import nodes
26class LocalsDictNodeNG(_base_nodes.LookupMixIn):
27 """this class provides locals handling common to Module, FunctionDef
28 and ClassDef nodes, including a dict like interface for direct access
29 to locals information
30 """
32 # attributes below are set by the builder module or by raw factories
33 locals: dict[str, list[InferenceResult]]
34 """A map of the name of a local variable to the node defining the local."""
36 def qname(self) -> str:
37 """Get the 'qualified' name of the node.
39 For example: module.name, module.class.name ...
41 :returns: The qualified name.
42 :rtype: str
43 """
44 # pylint: disable=no-member; github.com/pylint-dev/astroid/issues/278
45 if self.parent is None:
46 return self.name
47 try:
48 return f"{self.parent.frame().qname()}.{self.name}"
49 except ParentMissingError:
50 return self.name
52 def scope(self) -> Self:
53 """The first parent node defining a new scope.
55 :returns: The first parent scope node.
56 :rtype: Module or FunctionDef or ClassDef or Lambda or GenExpr
57 """
58 return self
60 def scope_lookup(
61 self, node: _base_nodes.LookupMixIn, name: str, offset: int = 0
62 ) -> tuple[LocalsDictNodeNG, list[nodes.NodeNG]]:
63 """Lookup where the given variable is assigned.
65 :param node: The node to look for assignments up to.
66 Any assignments after the given node are ignored.
68 :param name: The name of the variable to find assignments for.
70 :param offset: The line offset to filter statements up to.
72 :returns: This scope node and the list of assignments associated to the
73 given name according to the scope where it has been found (locals,
74 globals or builtin).
75 """
76 raise NotImplementedError
78 def _scope_lookup(
79 self, node: _base_nodes.LookupMixIn, name: str, offset: int = 0
80 ) -> tuple[LocalsDictNodeNG, list[nodes.NodeNG]]:
81 """XXX method for interfacing the scope lookup"""
82 try:
83 stmts = _filter_stmts(node, self.locals[name], self, offset)
84 except KeyError:
85 stmts = ()
86 if stmts:
87 return self, stmts
89 # Handle nested scopes: since class names do not extend to nested
90 # scopes (e.g., methods), we find the next enclosing non-class scope
91 pscope = self.parent and self.parent.scope()
92 while pscope is not None:
93 if not isinstance(pscope, scoped_nodes.ClassDef):
94 return pscope.scope_lookup(node, name)
95 pscope = pscope.parent and pscope.parent.scope()
97 # self is at the top level of a module, or is enclosed only by ClassDefs
98 return builtin_lookup(name)
100 def set_local(self, name: str, stmt: nodes.NodeNG) -> None:
101 """Define that the given name is declared in the given statement node.
103 .. seealso:: :meth:`scope`
105 :param name: The name that is being defined.
107 :param stmt: The statement that defines the given name.
108 """
109 # assert not stmt in self.locals.get(name, ()), (self, stmt)
110 self.locals.setdefault(name, []).append(stmt)
112 __setitem__ = set_local
114 def _append_node(self, child: nodes.NodeNG) -> None:
115 """append a child, linking it in the tree"""
116 # pylint: disable=no-member; depending by the class
117 # which uses the current class as a mixin or base class.
118 # It's rewritten in 2.0, so it makes no sense for now
119 # to spend development time on it.
120 self.body.append(child) # type: ignore[attr-defined]
121 child.parent = self
123 @overload
124 def add_local_node(
125 self, child_node: nodes.ClassDef, name: str | None = ...
126 ) -> None: ...
128 @overload
129 def add_local_node(self, child_node: nodes.NodeNG, name: str) -> None: ...
131 def add_local_node(self, child_node: nodes.NodeNG, name: str | None = None) -> None:
132 """Append a child that should alter the locals of this scope node.
134 :param child_node: The child node that will alter locals.
136 :param name: The name of the local that will be altered by
137 the given child node.
138 """
139 if name != "__class__":
140 # add __class__ node as a child will cause infinite recursion later!
141 self._append_node(child_node)
142 self.set_local(name or child_node.name, child_node) # type: ignore[attr-defined]
144 def __getitem__(self, item: str) -> SuccessfulInferenceResult:
145 """The first node the defines the given local.
147 :param item: The name of the locally defined object.
149 :raises KeyError: If the name is not defined.
150 """
151 return self.locals[item][0]
153 def __iter__(self):
154 """Iterate over the names of locals defined in this scoped node.
156 :returns: The names of the defined locals.
157 :rtype: iterable(str)
158 """
159 return iter(self.keys())
161 def keys(self):
162 """The names of locals defined in this scoped node.
164 :returns: The names of the defined locals.
165 :rtype: list(str)
166 """
167 return list(self.locals.keys())
169 def values(self):
170 """The nodes that define the locals in this scoped node.
172 :returns: The nodes that define locals.
173 :rtype: list(NodeNG)
174 """
175 # pylint: disable=consider-using-dict-items
176 # It look like this class override items/keys/values,
177 # probably not worth the headache
178 return [self[key] for key in self.keys()]
180 def items(self):
181 """Get the names of the locals and the node that defines the local.
183 :returns: The names of locals and their associated node.
184 :rtype: list(tuple(str, NodeNG))
185 """
186 return list(zip(self.keys(), self.values()))
188 def __contains__(self, name) -> bool:
189 """Check if a local is defined in this scope.
191 :param name: The name of the local to check for.
192 :type name: str
194 :returns: Whether this node has a local of the given name,
195 """
196 return name in self.locals
199class ComprehensionScope(LocalsDictNodeNG):
200 """Scoping for different types of comprehensions."""
202 scope_lookup = LocalsDictNodeNG._scope_lookup
204 generators: list[nodes.Comprehension]
205 """The generators that are looped through."""