hakorune/docs/development/current/main/phase46-norm-canon-p2-mid.md

Phase 46: Normalized Canonical P2-Mid Promotion

Status: Implemented ✅ (2025-12-12) Test Coverage: 937/937 PASS

Goal

Promote P2-Mid patterns (_atoi real, _parse_number real) to canonical Normalized→MIR(direct) route, alongside existing P2-Core patterns.

Scope

In Scope (P2 patterns):

• JsonparserAtoiReal → canonical Normalized
• JsonparserParseNumberReal → canonical Normalized

Out of Scope (deferred to future phases):

• Pattern3 (if-sum) → NORM-P3
• Pattern4 (continue) → NORM-P4
• Selfhost complex loops → separate phases

Rationale

With Phase 43/245B infrastructure complete, JsonParser P2-Mid loops (_atoi, _parse_number) are production-ready for canonical Normalized route:

1. Proven infrastructure: DigitPos dual-value, NumberAccumulation, StepSchedule all working
2. Real-world validation: JsonParser _atoi/_parse_number tests passing (937/937)
3. Clear boundary: P2 vs P3/P4 separation simplifies rollout

After Phase 46, P2 line becomes "Normalized-first" - Structured→MIR is legacy/comparison only.

Implementation Checklist

1. Expand Canonical Set (shape_guard.rs)

✅ Update is_canonical_shape() to include:

• JsonparserAtoiReal
• JsonparserParseNumberReal

✅ Update doc comments:

• "Phase 41 canonical set" → "Phase 46 canonical set: P2-Core + P2-Mid"

2. Verify Bridge Routing (bridge.rs)

✅ Confirm canonical_shapes() routing unchanged (already calls is_canonical_shape())

✅ Update comments:

• "Phase 41: P2-Core only" → "Phase 46: P2-Core + P2-Mid (_atoi/_parse_number real)"

3. Add/Update Tests

✅ Verify existing tests cover canonical routing:

• normalized_pattern2_jsonparser_atoi_real_vm_bridge_direct_matches_structured
• normalized_pattern2_jsonparser_parse_number_real_vm_bridge_direct_matches_structured

✅ Add new unit test (normalized_dev feature only):

• Verify canonical_shapes includes _atoi real / _parse_number real
• Verify bridge always routes to Normalized→MIR(direct)

4. Update Documentation

✅ Add Phase 46 section to joinir-architecture-overview.md:

• "JsonParser _skip_whitespace / _atoi / _parse_number now canonical Normalized"
• Link to P3/P4 future work (NORM-P3/NORM-P4)

✅ Add Phase 46 entry to CURRENT_TASK.md:

• Scope: P2-Core/P2-Mid canonical (P3/P4 out of scope)
• Done condition: shape_guard + bridge + tests + docs

Canonical Set Evolution

Phase	Canonical Patterns	Description
Phase 41	P2-Core: Pattern2Mini, skip_ws mini/real, atoi mini	Initial canonical set
Phase 46	+ P2-Mid: atoi real, parse_number real	JsonParser production patterns
Future	P3/P4, Selfhost loops	Deferred to NORM-P3/NORM-P4

Testing Strategy

Existing coverage (no new tests required):

• normalized_joinir_min.rs already tests _atoi real / _parse_number real
• VM output comparison verified (Normalized vs Structured)

New unit test (shape + bridge integration):

• Verify canonical_shapes() includes P2-Mid
• Feature-gated: #[cfg(feature = "normalized_dev")]

Benefits

1. Clear P2 boundary: All JsonParser P2 loops now Normalized-first
2. Simplified mental model: P2 = Normalized canonical, P3/P4 = future work
3. Production-ready: _atoi/_parse_number real validated through Phase 246-EX/247-EX

Next Steps (Out of Scope)

• NORM-P3: Pattern3 (if-sum) Normalized support
• NORM-P4: Pattern4 (continue) Normalized support
• Selfhost: Complex loops from selfhost compiler

References

• Completion Summary: PHASE_43_245B_NORMALIZED_COMPLETION.md
• Phase 44 Capabilities: phase44-shape-capabilities-design.md
• Phase 45 Mode: phase45-norm-mode-design.md