ml_switcheroo.core.rewriter.patcher
===================================

.. py:module:: ml_switcheroo.core.rewriter.patcher

.. autoapi-nested-parse::

   Graph Patcher for AST Surgery.

   This module implements the execution phase of the Graph-Guided Rewriting pipeline.
   It applies a set of topological mutations (Deletions, Replacements) generated
   by the ``GraphDiffer`` to the concrete syntax tree (CST) of the source code.

   It bridges the gap between the Abstract Logical Graph and the physical source code
   by using **Provenance Tracking** to locate the exact CST nodes corresponding
   to graph nodes, and the **Snippet Emitter** to generate valid replacement code.



Classes
-------

.. autoapisummary::

   ml_switcheroo.core.rewriter.patcher.PatchAction
   ml_switcheroo.core.rewriter.patcher.DeleteAction
   ml_switcheroo.core.rewriter.patcher.ReplaceAction
   ml_switcheroo.core.rewriter.patcher.GraphPatcher


Module Contents
---------------

.. py:class:: PatchAction

   Base class for patch instructions.


   .. py:attribute:: node_id
      :type:  str


.. py:class:: DeleteAction

   Bases: :py:obj:`PatchAction`


   Instruction to remove a node from the AST.
   Used for nodes that have been fused into others or pruned.


.. py:class:: ReplaceAction

   Bases: :py:obj:`PatchAction`


   Instruction to replace an existing node with a new code snippet.

   Commonly used for:
   1. Replacing a sequence anchor (e.g. Conv2d) with a Fused Block.
   2. Swapping layer definitions in `__init__`.

   .. attribute:: new_node

      The logical definition of the new component.

   .. attribute:: input_vars

      List of variable names to pass as arguments.

   .. attribute:: output_var

      The variable name to assign result to.

   .. attribute:: is_init

      If True, uses `emit_init` logic (assignments).
      If False, uses `emit_call` logic (executions).


   .. py:attribute:: new_node
      :type:  ml_switcheroo.compiler.ir.LogicalNode


   .. py:attribute:: input_vars
      :type:  List[str]
      :value: []



   .. py:attribute:: output_var
      :type:  str
      :value: 'x'



   .. py:attribute:: is_init
      :type:  bool
      :value: False



.. py:class:: GraphPatcher(plan: List[PatchAction], provenance: Dict[str, libcst.CSTNode], emitter: ml_switcheroo.compiler.backends.python_snippet.PythonSnippetEmitter)

   Bases: :py:obj:`libcst.CSTTransformer`


   LibCST Transformer that applies graph optimizations to source code.

   It builds a reverse-lookup map of the Provenance Registry to identify
   CST nodes by object identity, then checks against the Transformation Plan
   during traversal to apply Deletes or Replacements.


   .. py:attribute:: plan


   .. py:attribute:: provenance


   .. py:attribute:: emitter


   .. py:method:: leave_Assign(original_node: libcst.Assign, updated_node: libcst.Assign) -> Union[libcst.Assign, libcst.SimpleStatementLine, libcst.RemovalSentinel]

      Intercepts Assignment statements (e.g. `self.conv = ...`, `y = func(x)`).



   .. py:method:: leave_Expr(original_node: libcst.Expr, updated_node: libcst.Expr) -> Union[libcst.Expr, libcst.SimpleStatementLine, libcst.RemovalSentinel]

      Intercepts Expression statements (e.g. `func(x)` without assignment).



   .. py:method:: leave_Call(original_node: libcst.Call, updated_node: libcst.Call) -> Union[libcst.Call, libcst.BaseExpression, libcst.RemovalSentinel]


   .. py:method:: leave_SimpleStatementLine(original_node: libcst.SimpleStatementLine, updated_node: libcst.SimpleStatementLine) -> Union[libcst.SimpleStatementLine, libcst.RemovalSentinel]

      Cleans up statements that became empty due to children deletion.