Module engine_bridge 

Phase 4: Engine convergence bridge between OpEvent operations and Formualizer-native structural mutation APIs.

This module provides the mapping layer for routing structural operations through formualizer_eval::Engine instead of the umya token-rewrite path. Currently, this is a stub/interface layer that documents the target API and provides the conversion types. Full integration requires the Formualizer engine to expose insert_rows, delete_rows, insert_columns, delete_columns APIs at the graph/store level.

Migration Path

1. Current state: Structure ops mutate the workbook via umya_spreadsheet and rewrite formula tokens via string manipulation in apply_structure_ops_to_file.

2. Target state: Structure ops mutate the Formualizer dependency graph first, then serialize through umya only at materialization boundaries.

3. Parity requirement: dry_run_impact predictions must match applied mutation results whether executing via umya or Formualizer paths.

Structs

EngineApplyResult

Result of applying a structural operation through the engine.

Enums

EngineStructureOp

Describes a structural mutation to be applied through the engine.

Functions

change_event_to_op_payload

Maps a Formualizer ChangeEvent back to an OpEvent-compatible payload.

op_event_to_engine_op

Convert an OpEvent with a structural kind into an EngineStructureOp.

predict_engine_impact

Predict the impact of an engine structure operation.