FESADev/phases/abaqus-input-parser/step1.md

Step 1: mesh-keyword-parser

Read First

Read these files before editing:

• /AGENTS.md
• /docs/PRD.md
• /docs/ARCHITECTURE.md
• /docs/ADR.md
• /docs/io-definitions/abaqus-input-parser-io.md
• /src/fesa/model/domain.hpp
• /src/fesa/model/node.hpp
• /src/fesa/model/element.hpp
• /tests/unit/model_domain_test.cpp

Review step 0 output before implementing. Keep this step limited to parser API and mesh keyword mapping.

Task

Add the first C++ parser slice under /src/fesa/io/abaqus/.

Required behavior:

• Provide a small InputParser that accepts an in-memory .inp string and returns a parse result containing fesa::model::Domain and fesa::core::Status.
• Parse *HEADING as accepted but not yet stored.
• Parse *NODE data lines into Domain::add_node.
• Parse *ELEMENT, TYPE=<type> data lines into Domain::add_element.
• Support only two-node line/bar element names needed by the current model: T2D2, T3D2, B31, and C3D2.
• Map T2D2, T3D2, and C3D2 to ElementTopology::truss2; map B31 to ElementTopology::bar2.
• Use PropertyId{0} for elements in this first mesh-only slice because section parsing is introduced later.
• Treat keywords and parameter names case-insensitively.
• Skip blank lines and comment lines that begin with **.

Keep implementation C++17/MSVC-compatible. Do not introduce external libraries, regex-heavy parser frameworks, JavaScript, TypeScript, or npm fallbacks.

Tests To Write First

Add /tests/unit/abaqus_input_parser_mesh_test.cpp before production code.

The test must first fail because fesa/io/abaqus/input_parser.hpp does not exist, then pass after implementation. It should verify:

• a small input with *HEADING, *NODE, and *ELEMENT, TYPE=T3D2 returns Status::is_ok() == true;
• the returned Domain contains the expected node ids and 3D coordinates;
• the returned Domain contains the expected element id, topology, connectivity, and PropertyId{0};
• keyword and parameter casing are accepted case-insensitively.

Acceptance Criteria

ctest --test-dir build/msvc-debug --output-on-failure -C Debug -R abaqus_input_parser_mesh_test
python -m unittest discover -s scripts -p "test_*.py"
python scripts/validate_workspace.py

Verification Procedure

1. Run the targeted CTest after writing the test and before production code; confirm the failure is due to the missing parser API.
2. Implement the minimum code needed for the test to pass.
3. Run all acceptance criteria commands.
4. Confirm C++ production changes have a related C++ test file.
5. Update phases/abaqus-input-parser/index.json step 1:
   • success: "status": "completed", "summary": "Mesh keyword parser maps NODE and ELEMENT data into Domain"
   • error after three attempts: "status": "error", "error_message": "<specific error>"
   • blocked: "status": "blocked", "blocked_reason": "<specific reason>"

Forbidden

• Do not add set, material, section, load, boundary condition, output request, include-file, or HDF5 behavior in this step.
• Do not mutate reference artifacts.