FESADev/phases/1-linear-static-mitc4/step3.md

Step 3: parser-foundation

Sprint Contract

Objective

Implement the Abaqus input lexical/keyword parser foundation plus Factory + Registry plumbing for Phase 1 objects.

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
• /phases/1-linear-static-mitc4/step2.md

Scope

• Tokenize Abaqus keyword lines, parameters, data lines, comments, continuations if documented, and source locations.
• Add a parser result shape that returns Domain data or diagnostics.
• Add keyword Factory + Registry structure without completing every Phase 1 keyword.
• Add smoke parsing for a tiny supported subset such as *Node and *Element, TYPE=S4.

Allowed Files

• include/**
• src/**
• tests/**
• PLAN.md
• PROGRESS.md
• phases/1-linear-static-mitc4/index.json

Explicit Non-Goals

• Do not complete all Phase 1 Abaqus keywords in this step.
• Do not silently accept unsupported keywords or unknown parameters.
• Do not parse quad_01.inp as a supported Phase 1 case.

Tests To Write First

• Lexer tests for keyword names, parameters, comments, blank lines, and source locations.
• Registry tests for supported and unsupported keyword dispatch.
• Parser smoke tests for minimal nodes and S4 elements.

Reference Artifacts

• None. Existing references/quad_01.inp is not a Phase 1 parser acceptance case.

Acceptance Commands

python scripts/validate_workspace.py

Evaluator Checklist

• Unsupported input produces diagnostics with line context.
• Factory + Registry is present and parser logic is not hardwired into Domain constructors.
• Parser tests do not expand Phase 1 support beyond docs/ABAQUS_INPUT_SUBSET.md.

Handoff Requirements

• Record progress and validation in PROGRESS.md.
• Update PLAN.md if parser-scope risks change.
• Update the matching phase index entry: use completed with a one-line summary, or blocked with blocked_reason, or error with error_message.

Verification

1. Run the acceptance command.
2. Inspect parser tests for line-numbered diagnostic coverage.

Do Not

• Do not normalize away Abaqus labels that later diagnostics or references need.