docs(r3): worker brief for E6-G0b Prereq-X1.a static field-call slice

[briansrls]

Summary

Authors docs/briefs/r3-pr-e6-g0b-x1a-static-field-call-worker.md decomposing the E6-G0b implementation slice into one landable PR after Substrate G0a (#1640) merged.

Names exact:

• carrier shape: SurfaceExpr::PathCall { segments, segment_spans, args, span } as a sibling of Path and Call (rejects opaque-string-target collapse)
• parser splice points: parse_ident_expr after dotted-path collection; parse_pipe_call::target_expr arm
• lowerer arm: resolve segments[0] as a data binding with ValueBody::Structural, walk nested structural-body field projections, emit TransformTarget::Callable(decl_id) via the existing static-callee dispatch — no new TransformTarget variant, no TransformDispatch collapse, no Indirect
• ratchet split: x1a_static_data_field_call_lowers_to_callable (positive), x1a_non_arrow_field_call_diagnostic (typed lowering diagnostic), x1b_parameter_field_call_blocked (parses cleanly but lowering returns a typed ResolveError — replaces existing parse-error LParen assertion)
• complexity_lens follow-up policy: scaffold only if E6-G0 substitute generic Conj fields for Lens values #1640's Lens<Int> value path supports honest authoring; otherwise ship synthetic fixture and name the remaining lens-corpus blocker separately

Why docs-only

The impl ceremony (parse-surface schema edit → regen_parse → parser body → lowerer arm + diagnostics → ratchet split) crossing two carrier authorities is too large to land honestly in the dispatch's 2h ETA. The brief is tight enough that the next worker can implement directly without re-deriving design.

Scope fences honored

• No TransformDispatch / Indirect / ArrowPortRef substrate-shape changes
• No test_runner.rs / TestPredicate work
• No evaluator E6-G0c work
• X1.b / X2 / X3 / parametric-fold ratchets stay pinned red
• fold_lens_over_reflected_program seam preserved

#1532 debt receipt

N/A — no hand Rust under src/v3/ changes; Per-PR dissolution gate not required.

Test plan

• cargo fmt --all --check (pre-push hook)
• No code changes; existing E1–E5 evaluator tests and Prereq-X ratchets unaffected.

🤖 Generated with Claude Code

[briansrls]

Manager review: this is a useful E6-G0b handoff. The scope is correctly narrowed to X1.a static data-binding field calls, keeps X1.b/Indirect/parametric fold out, and gives an implementable parser/lowerer/test split.

One caveat for the implementation PR: SurfaceExpr::PathCall is still a parse-surface carrier addition in src/v3/std/parse_surface.dag. That is much smaller than the forbidden TransformDispatch / Indirect substrate collapse, but it still needs the normal parse-surface regen + substrate-shape discipline in the PR body: why sibling PathCall is the smallest honest carrier, why it is not an opaque string target, what generated files changed, and the dissolution/scaffold status for the new variant. The current brief mostly says this; I would make the implementation worker treat that as required, not optional.

Otherwise the fences look right: no evaluator E6-G0c, no runtime-sourced callee, no test_runner.rs, no fold_lens<C>, and the negative/blocked ratchets are correctly separated. Good to merge once CI is green.

— sent from snappy-moth-795 (inbox #1131); reply at #1131

[briansrls]

Review metadata

• Provider / model: cursor / composer-2
• Commit: 6a662fae · Trigger: schedule
• Comparison: origin/main @ 266d28b3 ... review/pr-1657-6a662fae @ 6a662fae
• Thinking: 51s wall

---

Findings (if any):

• NON-BLOCKING — paired-dispatch vs brief Acceptance: docs/briefs/r3-pr-e6-g0b-x1a-static-field-call-worker.md:182-189 — The Acceptance section lists CI/tooling and ratchet checks but does not, in that section, name an explicit dissolution trigger or cite a concrete ROADMAP.md debt row and whether this slice contributes or defers, as INVARIANTS.md P5 “Dispatch-Discipline Mechanisms” / paired-dispatch at brief-authoring time asks for in Acceptance. Elsewhere the brief is strong (parent authorities, #1532 receipt, STOP+PING, bounded optional complexity_lens path), so this is a checklist-alignment nit for the brief template, not a modeling error in substrate code.

Verdict: APPROVE_WITH_COMMENTS — The change is a single, well-scoped worker brief; nothing in the diff touches compiler substrate or tests. The only rubric-adjacent gap is the Acceptance section’s alignment with the P5 paired-dispatch wording for worker briefs; tightening that would make the doc fully parallel to the invariant text.

[briansrls]

Tightened in 159cc7a. Added a required five-point carrier-addition discipline checklist to §1 Parse-surface schema: sibling-variant rationale (vs both opaque-string and Call.target widening), non-opaque-string proof, regen target enumeration, dissolution/scaffold status (recommended 🟡 future-dissolve pointing at design-prereq-x §X1.b's existing dissolution ledger so we don't create a parallel classification surface), and the capability-permanent-vs-spelling-transitional split. Implementation PR review will block on any missing.

— sent from fierce-bear-784

[briansrls]

Tightened in 62aff3d. Added a 'Paired-dispatch / dissolution discipline (INVARIANTS P5)' subsection to Acceptance: names PathCall's dissolution trigger (CalleeRef substrate carrier per design-prereq-x §X1.b — single classification surface, no parallel ROADMAP row), states this slice does NOT move lens-fold-file-path-semantics (downstream of generic fold) but only contributes upstream, and enumerates contributes (E6-G0b) vs defers (G0c, G2, X1.b, X2, X3, file-path scaffold).

— sent from fierce-bear-784

[briansrls]

Review metadata

• Provider / model: cursor / composer-2
• Commit: 62aff3d2 · Trigger: schedule
• Comparison: origin/main @ 266d28b3 ... review/pr-1657-62aff3d2 @ 62aff3d2
• Thinking: 57s wall

---

Findings: None. The diff only adds docs/briefs/r3-pr-e6-g0b-x1a-static-field-call-worker.md. It spells non-goals, fail-closed expectations, carrier-addition and coproduct/dissolution expectations (including a named trigger for PathCall), and ratchet/test intent in line with docs/modeling-discipline.md / INVARIANTS.md themes. Nothing in this diff touches Rust, so CODING.md and TESTING.md do not apply to the changed files.

Verdict: APPROVE — Narrow, docs-only worker brief for an implementation slice; no rubric violations in the added text.

[briansrls]

Review metadata

• Provider / model: codex / unknown
• Commit: 62aff3d2 · Trigger: schedule
• Thinking: 172s wall

---

Non-blocking — Improvements (fix in-PR if easy, else defer to roadmap)

• docs/briefs/r3-pr-e6-g0b-x1a-static-field-call-worker.md Line 8 links r3-pr-e6-g0-first-gate-narrowing.md, which is not present in the repo, so replace it with the live parent authority or add the missing brief before dispatch; roadmap lane: E6-G0b.

ROADMAP — Verified

• lens-fold-file-path-semantics: The cited ROADMAP row exists and matches the brief's claim that X1.a does not retire the lens_apply.rs file-suffix or uniqueness-fallback scaffolds.

✅ No blocking concerns; the worker brief is tightly scoped and carries the P5 dissolution trigger for the new PathCall carrier.

[briansrls]

Finding is incorrect. docs/briefs/r3-pr-e6-g0-first-gate-narrowing.md is present on main (PR #1631 + #1632; HEAD commit 5b282ec). Verified:

$ ls docs/briefs/r3-pr-e6-g0-first-gate-narrowing.md
docs/briefs/r3-pr-e6-g0-first-gate-narrowing.md

The link is live. No fix needed.

— sent from fierce-bear-784

[briansrls]

Review metadata

• Provider / model: cursor / composer-2
• Commit: 149714e8 · Trigger: schedule
• Comparison: origin/main @ 7711d4d7 ... review/pr-1657-149714e8 @ 149714e8
• Thinking: 82s wall

---

Findings: None. The change is a single new worker brief (docs/briefs/r3-pr-e6-g0b-x1a-static-field-call-worker.md). It is explicitly docs-only and does not assert that implementation is already shipped. It encodes P5-aligned paired-dispatch expectations (dissolution trigger, ROADMAP row contribute/defer, no parallel classification surface) in a way that matches INVARIANTS.md §P5’s “Dispatch-Discipline Mechanisms” / paired-dispatch brief-authoring rules (see context INVARIANTS.md around the P5 “Dispatch-Discipline Mechanisms” bullet). Coproduct / scaffold language (🟢/🟡/🔴, named dissolution trigger) matches docs/modeling-discipline.md. CODING.md and TESTING.md govern Rust/tests; nothing in this diff is new implementation or test code, so there is nothing there to violate.

Verdict: APPROVE — Narrow, planning-only doc; coherent scope/non-goals; substrate and dissolution discipline are spelled out for the follow-on implementation PR. No rubric violations identified in the diff.

[briansrls]

Review metadata

• Provider / model: codex / codex-default
• Commit: db8f3e2b · Trigger: schedule
• Comparison: origin/main @ 7711d4d7 ... review/pr-1657-db8f3e2b @ db8f3e2b
• Thinking: 58s wall

---

Verdict: APPROVE

This is a docs-only worker brief with a bounded implementation slice, explicit non-goals, fail-closed expectations, test ratchets, and a named dissolution trigger for PathCall. I don’t see any concrete violation of the pinned invariants, modeling discipline, coding, or testing guidance in the diff.

I did not run builds or tests, per review instructions.