FESADev/phases/1-structure-alignment-refactor/step4.md

Sprint Contract: IO Parser Extraction

Objective

Move the Abaqus Phase 1 input parser into the IO module while preserving the documented strict parser subset and unsupported-feature diagnostics.

Required Reading

• /AGENTS.md
• /PROGRESS.md
• /PLAN.md
• /docs/README.md
• /docs/HARNESS_ENGINEERING.md
• /docs/ARCHITECTURE.md
• /docs/ADR.md
• /docs/ABAQUS_INPUT_SUBSET.md
• /docs/VERIFICATION_PLAN.md
• /phases/1-structure-alignment-refactor/step0-architecture-map.md
• /phases/1-structure-alignment-refactor/step2.md

Scope

• Extract KeywordLine, ParseResult, AbaqusInputParser, and parser-only helpers into IO.
• Keep parser output in Domain.
• Preserve strict rejection for S4R, Part/Assembly/Instance, *Include, NLGEOM=YES, nonzero prescribed displacement, and unsupported keyword parameters.
• Keep normalized reference behavior for references/quad_02_phase1.inp.

Allowed Files

• include/fesa/fesa.hpp
• include/fesa/IO/
• src/IO/
• include/fesa/Core/
• src/Core/
• tests/
• CMakeLists.txt
• phases/1-structure-alignment-refactor/index.json
• PLAN.md
• PROGRESS.md

Explicit Non-Goals

• Do not add new Abaqus keyword support.
• Do not accept original references/quad_02.inp as a Phase 1 parser input.
• Do not change docs/ABAQUS_INPUT_SUBSET.md unless a purely clarifying note is required.
• Do not move results or reference comparator code in this step.

Tests To Write First

• Add or update an include/link test for fesa/IO parser headers.
• Preserve parser acceptance and rejection tests as characterization tests.
• Ensure original quad_02.inp unsupported provenance remains rejected where tested.

Reference Artifacts

• references/quad_02.inp
• references/quad_02_phase1.inp

Do not edit these files.

Acceptance Commands

python scripts/validate_workspace.py

Evaluator Checklist

• Parser code lives in IO and does not own analysis or assembly behavior.
• Parser subset discipline is unchanged.
• Diagnostics still include enough source context for malformed input.
• Domain remains the parser output boundary.
• Stored reference compatibility notes remain true.

Handoff Requirements

• Update this step status in phases/1-structure-alignment-refactor/index.json.
• Record moved parser files and any unsupported-feature behavior verified.

Do Not

• Do not normalize reference files inside parser code.
• Do not silently broaden parser compatibility while refactoring.