agent: builder model: opus max_turns: 90 budget_usd: 18 effort: medium —
from s / from a | b, parsed and checked (#1213 step 4)Score: the language topics (owner, 2026-11-03), #1213 (ADR-views-3, option D). Needs v3 on develop (the parameter marks): if keep does not parse, stop with blocked. Rust is allowed where the code is Rust (#1214); the check is new Nikaia. Read docs/specification/adr/adr-views-3.md D7-D10 and Part I 6.6 first. S=1, C~3-4 M.
Codes reserved for this brief (supervisor): NK1335 a way out hands back a view of a parameter the written from does not name; NK1336 a result that is a view with no from where there is no body to infer it from (a trait’s method, a function type, a foreign or Rust function). Add their rows to the NK1xxx row of Part III and to the compiler’s codes table. The caller rule (D9) uses the existing NK2305.
Owns:
crates/nikaia/src/parser/mod.rs (result types), crates/nikaia/src/ast/mod.rs, a new checker file crates/nikaia-std/src/tools/check_result_from.nika and its lowered file, the ledger writer’s views entry for a written from (D10: recorded as written), the two code rows, new tests under tests/compiler/.Not yours:
keeps.nika, lowered/keeps.rs, contracts/keeps.rs, contracts/sync.rs: read, never edit; a needed change goes under Needs:.from (D8): -> T from s and -> T from a | b after a result type, on functions, methods, trait methods and function types. Where written, every way out is checked against it (NK1335); where it must be written and is missing, NK1336. The ledger records a written from as written. Tests: first_word with from s (accepted), longest with from a | b (accepted), a body that returns a view of a parameter not named (refused), a trait method with a view result and no from (refused). Commit Part of #1213.keep parameter, while a view the result holds is still used, is refused with NK2305 naming the view, the call and the parameter, for a written and an inferred source alike. Check first whether NK2305 already covers the inferred case; build only what is missing. Tests: change of the source after the last use (accepted), before it (refused), a reassignment of the source while the view lives (accepted: D9 gives the buffer to the view). Commit Part of #1213.List under Body: every Rust function you added or changed, for #557 / #125.
A form Nikaia, std or the toolchain lacks is sorted per CLAUDE.md A missing form stops the work. A further defect: no second fix in this brief, file nothing, report it under Found: with its probe.
Rs2nika: none.
Both steps hold with tests. nikaia test tests/compiler --both-settings and tests/errors give every count as before plus the new tests; the it tests filtered on view, ledger, from; the guard set of .claude/agents/builder.md. Clippy clean; the lower-std fixpoint holds; the committed ledgers unchanged or their change explained in Body:. No changelog line.
from is ambiguous against an existing expression or type form (report both readings under Needs:); the work needs keeps.nika changed.
docs/builder-facts.md first. You work in /home/user/Nikaia on develop (the shared checkout). Build with CARGO_INCREMENTAL=0 cargo build --profile fast -p nikaia; use only /home/user/Nikaia/target/fast/nikaia.git add <files> only, never -a/-A; commit after each step. Never git reset, stash, checkout ., restore .; restore only your own files by name. An error in another agent’s file is escalated, not touched.lower-std changed, yours and others’. Do not edit docs/selfhosting-plan.md, docs/architect.md, docs/priorities.md, docs/bootstrap.md or scripts/self_hosting.py: rows for them go into Body: of your report.cargo fmt, cargo clippy --all-targets -- -D warnings, nikaia run scripts/pre-push.nika, and the gate of .claude/agents/builder.md. You commit; the supervisor pushes.CHANGELOG.md, badges; no new NK code. New tests in Nikaia only; never the full suite. No foreground sleep, no polling; scripts in files.NIKAIA_CACHE_LIMIT=2G; if df -h /home/user shows under 2 GB free, stop and report blocked. Never delete another checkout’s target/./home/user/Nikaia/docs/briefs/views/v4-result-from.md.report.md)Fields of docs/architect.md, Briefs and reports: Result: done|noop|partial|blocked (the bare word alone on that line: Result: done, never a summary after it, which cuts the batch, b869a 2026-10-27; Owner: is a question for the owner or none, never a role), Files, Commit, Body (optional, one paragraph for the commit message), Fixes, Pushed, Tests, Gate (green|red), Deviation, Found, Needs, Changelog, Owner, Disk freed, and for a move Rs2nika: (the kept N of M lines of rs2nika --score, then the three costliest hand edits; none for a task that moves no Rust). none where nothing, and then the bare word: Deviation: none (a note) cuts the batch (batch.nika compares exactly); a note goes into the commit message. Found: is only for a defect outside your change (it cuts the batch); a converter draft that came out wrong is no Found:, it is one of the costliest edits under Rs2nika:, which the converter lane reads (e12-4b 2026-10-27); how you solved your own step goes into the commit message. Deviation: is only a step of the brief built otherwise than written or not built (a choice the brief left to you, such as keep what X needs and say so, is no deviation: it goes into the commit message; nor is building two steps in one commit when every step is built, e12-3a 2026-10-27, nor a step another commit on develop already built, shown by your test failing with that commit’s change reverted, b889 2026-10-27: name the commit in Body:); how you verified (e.g. a test not run against the unfixed compiler) goes under Tests:. A noop says why under Tests: (what was probed), not under Deviation:. Final answer, one line: done <sha>, report <path> (or BLOCKED: ... / PUSH REJECTED ...).
Attribution: Co-Authored-By: Claude Opus 5.5 noreply@anthropic.com Claude-Session: https://claude.ai/code/session_01GFeMqxRbtUMiGVyDMxsvEq