Move inference methods to nodes module(s)

ChangeLog

@@ -19,6 +19,13 @@ Release date: TBA
   Closes #1780
   Refs #2140
 
+* Remove the ``inference`` module. Node inference methods are now in the module
+  defining the node, rather than being associated to the node afterward.
+
+  Closes #679
+
+* Move ``LookupMixIn`` to ``astroid.nodes._base_nodes`` and make it private.
+
 * Reduce file system access in ``ast_from_file()``.
 
 * Reduce time to ``import astroid`` by delaying ``astroid_bootstrapping()`` until

astroid/__init__.py

@@ -40,7 +40,7 @@
 
 # isort: on
 
-from astroid import inference, raw_building
+from astroid import raw_building
 from astroid.__pkginfo__ import __version__, version
 from astroid.astroid_manager import MANAGER
 from astroid.bases import BaseInstance, BoundMethod, Instance, UnboundMethod

astroid/bases.py

@@ -10,9 +10,9 @@
 import collections
 import collections.abc
 from collections.abc import Iterable, Iterator
-from typing import TYPE_CHECKING, Any, ClassVar, Literal
+from typing import TYPE_CHECKING, Any, Literal
 
-from astroid import nodes
+from astroid import decorators, nodes
 from astroid.const import PY310_PLUS
 from astroid.context import (
     CallContext,
@@ -28,7 +28,6 @@
 )
 from astroid.interpreter import objectmodel
 from astroid.typing import (
-    InferBinaryOp,
     InferenceErrorInfo,
     InferenceResult,
     SuccessfulInferenceResult,
@@ -346,7 +345,16 @@ class Instance(BaseInstance):
     def __init__(self, proxied: nodes.ClassDef | None) -> None:
         super().__init__(proxied)
 
-    infer_binary_op: ClassVar[InferBinaryOp[Instance]]
+    @decorators.yes_if_nothing_inferred
+    def infer_binary_op(
+        self,
+        opnode: nodes.AugAssign | nodes.BinOp,
+        operator: str,
+        other: InferenceResult,
+        context: InferenceContext,
+        method: SuccessfulInferenceResult,
+    ) -> Generator[InferenceResult, None, None]:
+        return method.infer_call_result(self, context)
 
     def __repr__(self) -> str:
         return "<Instance of {}.{} at 0x{}>".format(

astroid/constraint.py

@@ -8,16 +8,19 @@
 import sys
 from abc import ABC, abstractmethod
 from collections.abc import Iterator
-from typing import Union
+from typing import TYPE_CHECKING, Union
 
-from astroid import bases, nodes, util
+from astroid import nodes, util
 from astroid.typing import InferenceResult
 
 if sys.version_info >= (3, 11):
     from typing import Self
 else:
     from typing_extensions import Self
 
+if TYPE_CHECKING:
+    from astroid import bases
+
 _NameNodes = Union[nodes.AssignAttr, nodes.Attribute, nodes.AssignName, nodes.Name]
 
 

astroid/filter_statements.py

@@ -10,10 +10,14 @@
 
 from __future__ import annotations
 
+from typing import TYPE_CHECKING
+
 from astroid import nodes
-from astroid.nodes import node_classes
 from astroid.typing import SuccessfulInferenceResult
 
+if TYPE_CHECKING:
+    from astroid.nodes import _base_nodes
+
 
 def _get_filtered_node_statements(
     base_node: nodes.NodeNG, stmt_nodes: list[nodes.NodeNG]
@@ -44,7 +48,7 @@ def _get_if_statement_ancestor(node: nodes.NodeNG) -> nodes.If | None:
 
 
 def _filter_stmts(
-    base_node: node_classes.LookupMixIn,
+    base_node: _base_nodes.LookupMixIn,
     stmts: list[SuccessfulInferenceResult],
     frame: nodes.LocalsDictNodeNG,
     offset: int,

astroid/helpers.py

@@ -324,3 +324,25 @@ def object_len(node, context: InferenceContext | None = None):
     raise AstroidTypeError(
         f"'{result_of_len}' object cannot be interpreted as an integer"
     )
+
+
+def _higher_function_scope(node: nodes.NodeNG) -> nodes.FunctionDef | None:
+    """Search for the first function which encloses the given
+    scope.
+
+    This can be used for looking up in that function's
+    scope, in case looking up in a lower scope for a particular
+    name fails.
+
+    :param node: A scope node.
+    :returns:
+        ``None``, if no parent function scope was found,
+        otherwise an instance of :class:`astroid.nodes.scoped_nodes.Function`,
+        which encloses the given node.
+    """
+    current = node
+    while current.parent and not isinstance(current.parent, nodes.FunctionDef):
+        current = current.parent
+    if current and current.parent:
+        return current.parent
+    return None